ORCID Profile
0000-0002-2680-7473
Current Organisation
University of South Australia
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Publisher: S. Karger AG
Date: 1991
DOI: 10.1159/000177631
Abstract: Fat-free mass was measured by hydrodensitometry, electrical impedance and total body potassium before and after water and electrolyte loss induced by (a) the administration of the diuretic frusemide, and (b) sweat loss. All methods of measuring fat-free mass were shown by pilot experiments to have procedural reliability. The diuretic caused a reduction in apparent fat-free mass of 2.63 kg by the impedance method, of 2.33 kg by hydrodensitometry and of 1.8 kg by total body potassium. Water and electrolyte loss from sweating caused a fat-free loss of 2.3 kg, 2.7 kg and 1.3 kg by the same three procedures. Urinary potassium accounted for about one fifth of the observed 40K fat-free mass loss. Each method was thus clearly sensitive to the induced water loss. These data suggest that in evaluating the composition of weight loss, existing methods of measuring body composition do not distinguish between water and other more critical components of fat-free mass. It is thus essential that stable hydration levels are established for any longitudinal comparison of weight loss by these methods.
Publisher: Public Library of Science (PLoS)
Date: 23-10-2017
Publisher: Elsevier BV
Date: 08-2009
DOI: 10.1016/J.YPMED.2009.06.012
Abstract: To assess whether the activity pattern differs between normal weight and overweight boys across weekdays and weekend days. Physical activity was recorded every 2 s by accelerometry in 32 normal weight and 15 overweight boys aged 8-10 years for four weekdays and two weekend days (South-West England 2007). Summary activity measures and activity pattern characteristics (frequency, intensity and duration of > or =4 s (short) and > or =5-min (long) bouts of > or =light, > or =moderate, > or =vigorous, and > or =hard activity) were recorded. Normal weight boys accumulated more > or =hard activity (p<0.05) but other summary measures did not differ by weight status. However, the activity pattern differed in overweight relative to normal weight boys. The most frequent short bouts were shorter and less intense (p or =moderate long bouts were shorter and less frequent (p or =light, > or =moderate (and for overweight boys > or =vigorous) short bouts dropped-off) (p or =moderate bouts, relative to normal weight boys suggesting that the activity pattern may be important for weight control.
Publisher: Physical Education and Sport Faculty
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 26-07-2016
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.APMR.2013.03.018
Abstract: To investigate the utility of the differentiated rating of perceived exertion (RPE) for the self-regulation of submaximal wheelchair propulsion in novice users. Each participant completed a submaximal incremental test and a graded test to exhaustion to determine peak oxygen consumption (Vo(2)peak) on a wheelchair ergometer. On a separate day, two 12-minute intermittent bouts consisting of three 4-minute stages were completed at in idualized imposed power outputs equating to light (40% Vo(2)peak) and moderate (60% Vo(2)peak) intensity exercise. On a third occasion, participants were assigned to either the overall group or the peripheral group and were required to self-regulate 12-minute intermittent exercise according to either overall RPE or peripheral RPE reported during the corresponding imposed intensity trial. Laboratory facilities at a university. Preliminary population of able-bodied participants with no prior experience of wheelchair propulsion (N=18). Not applicable. Differences in oxygen consumption (Vo(2)), heart rate, blood lactate concentration, and power output between the imposed and self-regulated exercise trials. No difference was found in physiological responses between the moderate-intensity imposed and RPE-regulated trials in the peripheral group, whereas a significant (P<.05) underproduction in Vo(2) (1.76±.31 vs 1.59±.25L/min) and blood lactate concentration (2.8±0.90 vs 2.21±.83mmol/L) was seen in the overall group. In contrast, a significant (P<.05) overproduction was seen in the peripheral group at a light exercise intensity, whereas no difference was found between all variables during the light-intensity imposed and RPE-regulated trials in the overall group. Peripheral RPE enabled a more precise self-regulation during moderate-intensity wheelchair exercise in novice users. In contrast, overall RPE provided a more accurate stimulus when performing light-intensity propulsion.
Publisher: Informa UK Limited
Date: 2001
DOI: 10.1080/02640410152006108
Abstract: This study assessed the effects of stride length on symptoms of exercise-induced muscle damage after downhill running and whether the extent of the symptoms sustained in a repeated bout of downhill running are influenced by stride length manipulation in the first bout. Eighteen males aged 21.1 +/- 0.6 years (mean +/- s) were allocated to one of three groups for bout one: preferred stride frequency, overstride and understride. Bout two was performed 2 weeks later at the participants' preferred stride frequency. Maximal isometric force and perceived muscle soreness were assessed pre-test and 30 min, 24, 48 and 72 h post-exercise for each downhill run. Three-factor analyses of variance with repeated measures on time and bout were used for analysis. Results revealed a three-way interaction for soreness (F8,60 = 3.56, P < 0.05) and relative isometric strength (F5.0,37.8 = 3.2, P < 0.05). Post-hoc analyses revealed that, after bout one, the overstride group perceived most soreness and the understride group retained most strength. After the second bout, the overstride and preferred stride frequency groups perceived less soreness than the preferred stride frequency group in bout one. Strength retention was greater after bout two for all groups. In conclusion, strength retention after a repeated bout appears to be independent of the damage experienced in the initial bout of downhill running. However, understriding may provide least protection against soreness in a subsequent bout.
Publisher: Springer Science and Business Media LLC
Date: 07-2011
DOI: 10.1007/S00421-011-2053-6
Abstract: We examined whether a prior bout of eccentric exercise in the elbow flexors provided protection against exercise-induced muscle damage in the contralateral arm. Fifteen males (age 22.7 ± 2.1 years height 178.6 ± 6.8 cm, mass 75.8 ± 9.3 kg) were randomly assigned to two groups who performed two bouts of 60 eccentric contractions (30°/s) separated by 2 weeks: ipsilateral (n = 7, both bouts performed in the same arm), contralateral (n = 8, one bout performed in each arm). Strength, muscle soreness and resting arm angle (RAA) were measured at baseline and at 1, 24 and 48 h post exercise. Surface electromyography was recorded during both bouts of exercise. The degree of strength loss was attenuated (p < 0.05) in the ipsilateral group after the second bout of eccentric exercise (-22 cf. -3% for bout 1 and 2 at 24 h, respectively). Strength loss following eccentric exercise was also attenuated (p < 0.05) at 24 h in the contralateral group (-30 cf. 13% for bout 1 and 2, respectively). Muscle soreness (≈34 cf 19 mm) and change in RAA (≈5 cf. 3%) were also lower following the second bout of eccentric exercise (p < 0.05), although there was no difference in the overall change in these values between groups. Median frequency (MF) was decreased by 31% between bouts, with no difference between groups. Data support observations that the repeated bout effect transfers to the opposite (untrained) limb. The similar reduction in MF between bouts for the two groups provides evidence for a centrally mediated, neural adaptation.
Publisher: Elsevier BV
Date: 05-2004
Publisher: Springer Science and Business Media LLC
Date: 20-01-2016
DOI: 10.1007/S40279-015-0465-X
Abstract: Recently, several authors have proposed the use of a submaximal 'perceptually regulated exercise test' (PRET) to predict maximal oxygen uptake ([Formula: see text]). The PRET involves asking the in idual to self-regulate a series of short bouts of exercise corresponding to pre-set ratings of perceived exertion (RPE). The in idual linear relationship between RPE and oxygen uptake (RPE:[Formula: see text]) is then extrapolated to the [Formula: see text], which corresponds to the theoretical maximal RPE (RPE20). Studies suggest that prediction accuracy from this method may be better improved during a second PRET. Similarly, some authors have recommended an extrapolation to RPE19 rather than RPE20. The purpose of the meta-analysis was to examine the validity of the method of predicting [Formula: see text] from the RPE:[Formula: see text] during a PRET, and to determine the level of agreement and accuracy of predicting [Formula: see text] from an initial PRET and retest using RPE19 and RPE20. From a systematic search of the literature, 512 research articles were identified. The eligible manuscripts were those which used the relationship between the RPE≤15 and [Formula: see text], and used only the Borg's RPE scale. Ten studies (n = 274 in iduals) were included. For each study, actual and predicted [Formula: see text] from four subgroup outcomes (RPE19 in the initial test, RPE19 in the retest, RPE20 in the initial test, RPE20 in the retest) were identified, and then compared. The magnitude of the difference regardless of subgroup outcomes was examined to determine if it is better to predict [Formula: see text] from extrapolation to RPE19 or RPE20. The magnitude of differences was examined for the best PRET (test vs retest). The results revealed that [Formula: see text] may be predicted from RPE:[Formula: see text] during PRET in different populations and in various PRET modalities, regardless of the subgroup outcomes. To obtain greater accuracy of predictions, extrapolation to RPE20 during a retest may be recommended. The included studies reported poor selection bias and data collection methods. The [Formula: see text] may be predicted from RPE:[Formula: see text] during PRET, especially when [Formula: see text] is extrapolated to RPE20 during a second PRET.
Publisher: Wiley
Date: 17-04-2014
DOI: 10.1111/SMS.12234
Abstract: The study examined which of a number of different magnetic resonance (MR) methods were sensitive to detecting muscle damage induced by eccentric exercise. Seventeen healthy, physically active participants, with muscle damage confirmed by non-MR methods were tested 24 h after performing eccentric exercise. Techniques investigated whether damage could be detected within the quadriceps muscle as a whole, and in idually within the rectus femoris, vastus lateralis (VL), vastus medialis (VM), and vastus intermedius (VI). Relative to baseline values, significant changes were seen in leg and muscle cross-sectional areas and volumes and the resting inorganic phosphate concentration. Significant time effects over all muscles were also seen in the transverse relaxation time (T2) and apparent diffusion coefficient (ADC) values, with in idually significant changes seen in the VL, VM, and VI for T2 and in the VI for ADC. A significant correlation was found between muscle volume and the average T2 change (r = 0.59) but not between T2 and ADC or Pi alterations. There were no significant time effects over all muscles for magnetization transfer contrast images, for baseline pH, phosphocreatine (PCr), phosphodiester, or ATP metabolite concentrations or the time constant describing the rate of PCr recovery following exercise.
Publisher: Springer Science and Business Media LLC
Date: 12-1992
DOI: 10.1007/BF00665662
Publisher: Springer Science and Business Media LLC
Date: 23-08-2018
DOI: 10.1007/S40279-018-0969-2
Abstract: Intensified training is important for inducing adaptations to improve athletic performance, but detrimental performance effects can occur if prescribed inappropriately. Monitoring biomarker responses to training may inform changes in training load to optimize performance. This systematic review and meta-analysis aimed to identify biomarkers associated with altered exercise performance following intensified training. Embase, MEDLINE, CINAHL, Scopus and SPORTDiscus were searched up until September 2017. Included articles were peer reviewed and reported on biomarkers collected at rest in well-trained male athletes before and after periods of intensified training. The full text of 161 articles was reviewed, with 59 included (708 participants) and 42 (550 participants) meta-analysed. In total, 118 biomarkers were evaluated, with most being cellular communication and immunity markers (n = 54). Studies most frequently measured cortisol (n = 34), creatine kinase (n = 25) and testosterone (n = 20). Many studies reported decreased immune cell counts following intensified training, irrespective of performance. Moreover, reduced performance was associated with a decrease in neutrophils (d = - 0.57 95% confidence interval (CI) - 1.07 to - 0.07) and glutamine (d = - 0.37 95% CI - 0.43 to - 0.31) and an increase in urea concentration (d = 0.80 95% CI 0.30 to 1.30). In contrast, increased performance was associated with an increased testosterone:cortisol ratio (d = 0.89 95% CI 0.54 to 1.24). All remaining biomarkers showed no consistent patterns of change with performance. Many biomarkers were altered with intensified training but not in a manner related to changes in exercise performance. Neutrophils, glutamine, urea and the testosterone:cortisol ratio exhibited some evidence of directional changes that corresponded with performance changes therefore indicating potential to track performance. Additional investigations of the potential for these markers to track altered performance are warranted.
Publisher: Elsevier BV
Date: 1993
Publisher: Informa UK Limited
Date: 14-12-2019
DOI: 10.1080/02640414.2018.1522941
Abstract: This study compares test-retest reliability and peak exercise responses from r -incremented (RAMP) and maximal perceptually-regulated (PRET
Publisher: Human Kinetics
Date: 03-2018
Abstract: Purpose: To assess and compare the validity of internal and external Australian football (AF) training-load measures for predicting match exercise intensity (MEI/min) and player-rank score (PR Score ) using a variable dose-response model. Methods: A cohort of 25 professional AF players (23 ± 3 y, 188.3 ± 7.2 cm, 87.7 ± 8.4 kg) completed a 24-wk in-season macrocycle. In-season internal training and match load were quantified using session rating of perceived exertion (sRPE) and external load from satellite and accelerometer data. Using a training-impulse (TRIMP) calculation, external load (au) was represented as distance (TRIMP Dist ), distance ≥4.16 m/s (TRIMP HSDist ), and PlayerLoad (TRIMP PL ). In-season training load, MEI/min, and PR Score were applied to a variable dose-response model, which provided estimates of MEI/min and PR Score . Predicted MEI/min and PR Score were correlated with actual measures from each match. The magnitude of the difference between MEI/min and PR Score estimates for each model input and the difference between the precision of internal and external load measures to predict MEI/min and PR Score were calculated using the effect size ± 90% confidence interval (CI). Results: Estimates of MEI/min demonstrated very large associations with actual MEI/min ( r , 90% CI) (eg, TRIMP Dist .76 ± .13, and sRPE Skills .73 ± .14). Estimates of PR Score demonstrated associations of large magnitude with actual PR Score using the same inputs. Precision of actual MEI/min was lowest using sRPE compared with (ES ± 90% CI) TRIMP Dist , −.67 ± .34, and TRIMP PL , −.91 ± .39. There were trivial and unclear differences in the precision of PR Score estimates between TRIMP and sRPE inputs. Conclusions: Dose-response models from multiple training-load inputs can predict within-in idual variation of MEI/min and PR Score . Internal and external training-input methods exhibited comparable predictive power.
Publisher: Wiley
Date: 15-10-2008
DOI: 10.1111/J.1469-8986.2008.00712.X
Abstract: This study assessed the relationship of the rating of perceived exertion (RPE) with heart rate and pacing strategy during competitive running races of differing distance and course elevation. Nine men and women competed in a 7-mile road race (7-MR) and the Great West Run half marathon (GWR 13.1 miles). Heart rate, split mile time, and RPE were recorded throughout the races. The RPE was regressed against time and %time to complete the 7-MR and GWR. Although the rate of increase in RPE was greater in the 7-MR, there were no differences when expressed against %time (inferring that the brain uses a scalar timing mechanism). As the course elevation, distance, pacing strategy, and heart rate response varied between conditions, this study has provided evidence that the perceptual response may have distinct temporal characteristics during distance running. The results provide further evidence that RPE scales with the proportion of exercise time that remains.
Publisher: Elsevier BV
Date: 11-2014
Publisher: Human Kinetics
Date: 11-2022
Abstract: Purpose : To continuously measure body core temperature ( T c ) throughout a mass-participation ultramarathon in subelite recreational runners to quantify T c magnitude and the influence of aerobic fitness and body fat. Methods : Twenty-three participants (19 men and 4 women age 45 [9] y body mass 72.0 [9.3] kg body fat 26% [6%] peak oxygen uptake 50 [6] mL·kg −1 ·min −1 ) had gastrointestinal temperature measured during an 89-km ultramarathon. Prerace-to-postrace changes in body mass, plasma sodium, and fluid and food recall quantified body water balance. Results : In maximal environmental conditions of 26.3 °C and 53% humidity, 21 of the 23 participants finished in 10:28 (01:10) h:min while replacing 49% (27%) of sweat losses, maintaining plasma sodium (140 [3] mmol·L −1 ), and dehydrating by 4.1% (1.3%). Mean maximum T c was 39.0 (0.5) (range 38.2–40.1 °C) with 90% of race duration ≤39.0 °C. Mean maximum Δ T c was 1.9 (0.9) (0.9–2.7 °C) with 95% of race duration ≤2.0 °C. Over 0 to 45 km, associations between Δ T c and peak oxygen uptake (positive) and body fat (negative) were observed. Over 58 to 89 km, associations between T c and peak oxygen uptake (negative) and body fat (positive) were observed. Conclusions : Modest T c responses were observed in recreational ultramarathon runners. Runners with higher levels of aerobic fitness and lower levels of body fat demonstrated the greatest changes in T c during the first half of the race. Conversely, runners with lower levels of aerobic fitness and higher levels of body fat demonstrated the greatest absolute T c in the final third of the race.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2010
Publisher: Springer Science and Business Media LLC
Date: 22-04-0012
Publisher: Human Kinetics
Date: 2019
Abstract: Purpose : To determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football players. Methods : A total of 23 professional and semiprofessional Australian rules football players performed 6 CMJs and three 8-second 50-m runs every 30 seconds (SRT), 7 days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation, CV (±90% confidence intervals). Test–retest reliability was examined using the magnitude of the difference (effect size [±90% confidence interval]) from week 1 to week 2. The smallest worthwhile change was calculated as 0.25 × SD. Results : Good reliability (CVs = 6.6%–9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV less than smallest worthwhile change, indicating an ability to detect practically important changes in performance. Only peak velocity from the CMJ test possessed a CV less than smallest worthwhile change, exhibiting a limitation of this test in detecting practically meaningful changes within this environment. Conclusions : The results suggest that while all variables possess acceptable reliability, a SRT might offer to be a more sensitive monitoring tool than a CMJ test within high-performance Australian rules football, due to its greater ability for detecting practically important changes in performance.
Publisher: Elsevier BV
Date: 04-1997
Publisher: Springer Science and Business Media LLC
Date: 09-06-2006
DOI: 10.1007/S00421-006-0213-X
Abstract: The purpose of this study was to assess the validity of predicting maximal oxygen uptake [V(.-)((O)(2)(max))] from sub-maximal V(.-)((O)(2)) values elicited during perceptually regulated exercise tests of 2- and 4-min duration. Nineteen physically active men and women (age range 19-23 years) volunteered to participate in two graded exercise tests to volitional exhaustion to measure V(.-)((O)(2)(max)) [V(.-)((O)(2)(max))(GXT)], at the beginning and end of a 2-week period, and four incremental, perceptually regulated tests to predict [V(.-)((O)(2)(max))] in the intervening period. Effort production tests comprised 2 x 2-min and 2 x 4-min bouts on a cycle ergometer, perceptually regulated at intensities of 9, 11, 13, 15 and 17 on the Borg 6-20 rating of perceived (RPE) scale, in that order. In idual linear relationships between RPE and V(.-)((O)(2) for RPE ranges of 9-17, 11-17 and 9-15 were extrapolated to RPE 20 to predict [V(.-)((O)(2)(max))]. The prediction of [V(.-)((O)(2)(max))] was not moderated by gender. Although, [V(.-)((O)(2)(max))] estimated from RPE 9-17 of trial 1 of the 2-min protocol was significantly lower (P < 0.05) than [V(.-)((O)(2)(max))(GXT)], and V(.-)((O)(2)(max)) predicted from the 4-min trials, the V(.-)((O)(2)(max)) predicted from trial 2 of the 2-min protocol was a more accurate prediction of [V(.-)((O)(2)(max))(GXT)], across all trials. The intraclass correlation coefficient (R) was also higher between [V(.-)((O)(2)(max))(GXT)], and [V(.-)((O)(2)(max))] predicted from trial 2 of the 2-min protocol compared to both trials in the 4-min protocol (R = 0.95, 0.88 and 0.79, respectively). Similar results were observed for RPE ranges 9-15 and 11-17. Results suggest that a sub-maximal, perceptually guided, graded exercise protocol, particularly of a 2-min duration, provides acceptable estimates of maximal aerobic power, which are not moderated by gender.
Publisher: Springer Science and Business Media LLC
Date: 15-12-2015
DOI: 10.1007/S40279-015-0445-1
Abstract: Aerobic capacity (VO2max) is a strong predictor of health and fitness and is considered a key physiological measure in the healthy adult population. Submaximal step tests provide a safe, simple and ecologically valid means of assessing VO2max in both the general population and a rehabilitation setting. However, no studies have attempted to synthesize the existing knowledge regarding the validity of the multiple step-test protocols available to estimate VO2max in the healthy adult population. The objective of this study was to systematically review literature on the validity and reliability of submaximal step-test protocols to estimate VO2max in healthy adults (age 18-65 years). A systematic literature search of the MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library databases was performed. The search returned 690 studies that underwent the initial screening process. To be included, the study had to (1) have participants deemed to be healthy and aged between 18 and 65 years (2) assess VO2max by means of a submaximal step test against a graded exercise test (GXT) to volitional exhaustion and (3) be available in English. Reference lists from included articles were screened for additional articles. The primary outcome measures used were the validity statistics between the actual measured VO2max and predicted VO2max values, and the reported direction of the statistically significant difference between the measured VO2max and the predicted VO2max. The Quality Assessment Tool for Quantitative Studies was used to assess the risk of bias in each included study, and was adapted to the type of quantitative study design used. The combined database search produced 690 studies, from which 644 were excluded during the screening process. Following full-text assessment, a further 39 studies were excluded based on the eligibility criteria detailed previously. Four additional studies were located via the reference lists of the included studies, leaving 11 studies that fulfilled the inclusion criteria and which compared eight different step-test protocols against a direct measure of VO2max incurred during a maximal GXT. Validity measures varied, with a broad range of correlation coefficients reported across the 11 studies (r = 0.469-0.95). Of the 11 studies, two reported reliability measures, demonstrating good test-retest reliability [mean -0.8 ± 3.7 mL kg(-1) min(-1) (±7.7 % of the mean measured VO2max)]. Considering the relationship between VO2max and various markers of health, the use of step tests as a measure of health in both the general adult population and rehabilitation settings is advocated. Step tests provide a simple, effective and ecologically valid method of submaximally assessing VO2max that can be implemented in a variety of situations within the general adult population. Future research is needed to assess the reliability of the majority of the step-test procedures reviewed. Based on the validity measures, submaximal step-test protocols are an acceptable means of estimating VO2max in the generally healthy adult population. For tracking changes in cardiorespiratory fitness, the Chester Step test appears to be an appropriate tool due to its high test-retest reliability.
Publisher: BMJ
Date: 29-11-2007
Abstract: The purpose of this study was to assess whether maximal oxygen uptake (V.O(2 max)) could be predicted from submaximal ratings of perceived exertion (RPE) elicited during the multistage fitness test (MFT). Eleven female volunteers completed three maximal exercise tests in random order the MFT, a simulated MFT on a motorized treadmill and a graded exercise test to volitional exhaustion (GXT), also on a motorized treadmill. RPE values were recorded at the end of each 1 min stage in all three tests. Oxygen consumption (VO(2)) was recorded continuously during the treadmill tests. Measured V.O(2 max) values from the GXT and simulated MFT were not significantly different (48.2 and 47.5 ml/kg/min, respectively), but they were significantly higher than V.O(2 max) values predicted by the MFT (41.2 ml/kg/min, p<0.05). Regression of submaximal RPE values (7-17) elicited from the MFT and VO(2) values predicted by the MFT were extrapolated to RPE 20 to predict V.O(2 max). The RPE-predicted V.O(2 max) from the MFT (47.5 ml/kg/min) was similar to measured V.O(2 max). The findings suggest that submaximal RPE values can be used to provide acceptable estimates of V.O(2 max) which are more accurate than the published table values for the MFT. Furthermore, the use of RPE measures in conjunction with the MFT enhances the accuracy of V.O(2 max) prediction by the MFT.
Publisher: Frontiers Media SA
Date: 15-01-2021
DOI: 10.3389/FSPOR.2020.579278
Abstract: Purpose: This study aims to (1) establish GENEActiv intensity cutpoints in older adults and (2) compare the classification accuracy between dominant (D) or non-dominant (ND) wrist, using both laboratory and free-living data. Methods: Thirty-one older adults participated in the study. They wore a GENEActiv Original on each wrist and performed nine activities of daily living. A portable gas analyzer was used to measure energy expenditure for each task. Testing was performed on two occasions separated by at least 8 days. Some of the same participants ( n = 13) also wore one device on each wrist during 3 days of free-living. Receiver operating characteristic analysis was performed to establish the optimal cutpoints. Results: For sedentary time, both dominant and non-dominant wrist had excellent classification accuracy (sensitivity 0.99 and 0.97, respectively specificity 0.91 and 0.86, respectively). For Moderate to Vigorous Physical Activity (MVPA), the non-dominant wrist device had better accuracy (ND sensitivity: 0.90, specificity 0.79 D sensitivity: 0.90, specificity 0.64). The corresponding cutpoints for sedentary-to-light were 255 and 375 g · min (epoch independent: 42.5 and 62.5 mg), and those for the light-to-moderate were 588 and 555 g · min (epoch-independent: 98.0 and 92.5 mg) for the non-dominant and dominant wrist, respectively. For free-living data, the dominant wrist device resulted in significantly more sedentary time and significantly less light and MVPA time compared to the non-dominant wrist.
Publisher: Informa UK Limited
Date: 17-07-2008
DOI: 10.1080/02640410801930168
Abstract: The purpose of this study was to determine the effects of plyometric exercise on unilateral balance performance. Nine healthy adults performed baseline measurements on the dominant limb that consisted of: a 20-s unilateral stability test on a tilt balance board, where a higher stability index represented deterioration in balance performance isokinetic plantar flexion torque at 0.52 and 3.14 rad s(-1) muscle soreness in the calf region and resting plantar flexion angle. Plyometric exercise consisted of 200 counter-movement jumps designed to elicit symptoms of muscle damage, after which baseline measurements were repeated at 30 min, 24, 48, and 72 h. Perceived muscle soreness of the calf region increased significantly following the plyometric exercise protocol (F(4,32) = 17.24, P < 0.01). Peak torque was significantly reduced after the plyometric exercise protocol (F(4,32) = 7.49, P < 0.05), with greater loss of force at the lower angular velocity (F(4,32) = 3.46, P 0.05). The stability index was significantly increased (F(4,32) = 3.10, P < 0.05) above baseline (mean 2.3, s = 0.3) at 24 h (3.3, s = 0.4), after which values recovered. These results indicate that there is a latent impairment of balance performance following a bout of plyometric exercise, which has implications for both the use of skill-based activities and for increased injury risk following high-intensity plyometric training.
Publisher: BMJ
Date: 23-03-2004
Abstract: Objectives: To evaluate the reliability and validity of measures taken during the Chester step test (CST) used to predict VO 2 max and prescribe subsequent exercise. Methods: The CST was performed twice on separate days by 7 males and 6 females aged 22.4 (SD 4.6) years. Heart rate (HR), ratings of perceived exertion (RPE), and oxygen uptake (VO 2 ) were measured at each stage of the CST. Results: RPE, HR, and actual VO 2 were the same at each stage for both trials but each of these measures was significantly different between CST stages (p .0005). Intertrial bias ±95% limits of agreement (95% LoA) of HR reached acceptable limits at CST stage IV (−2±10 beats/min) and for RPE at stages III (0.2±1.4) and IV (0.5±1.9). Age estimated HRmax significantly overestimated actual HRmax of 5 beats/min (p = 0.016) and the 95% LoA showed that this error could range from an underestimation of 17 beats/min to an overestimation of 7 beats/min. Estimated versus actual VO 2 at each CST stage during both trials showed errors ranging between 11% and 19%. Trial 1 underestimated actual VO 2 max by 2.8 ml/kg/min (p = 0.006) and trial 2 by 1.6 ml/kg/min (not significant). The intertrial agreement in predicted VO 2 max was relatively narrow with a bias ±95% LoA of −0.8±3.7 ml/kg/min. The RPE and %HRmax (actual) correlation improved with a second trial. At all CST stages in trial 2 RPE:%HRmax coefficients were significant with the highest correlations at CST stages III ( r = 0.78) and IV ( r = 0.84). Conclusion: CST VO 2 max prediction validity is questioned but the CST is reliable on a test-retest basis. VO 2 max prediction error is due more to VO 2 estimation error at each CST stage compared with error in age estimated HRmax. The HR/RPE relation at % VO 2 max reliably represents the recommended intensity for developing cardiorespiratory fitness, but only when a practice trial of the CST is first performed.
Publisher: Springer Science and Business Media LLC
Date: 08-1990
DOI: 10.1007/BF00664342
Publisher: Informa UK Limited
Date: 2001
DOI: 10.1080/026404101750095295
Abstract: The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P < 0.05). Strength, pain and tenderness were unaffected by either bout of concentric exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.
Publisher: Oxford University Press (OUP)
Date: 27-07-2023
Abstract: Workplace health and safety (WHS) is an important responsibility falling on both employers and employees and is most effective when the perspectives of all stakeholders are considered. This study aimed to explore the facilitators and barriers to a voluntary workplace lung function surveillance program from the perspective of urban firefighters and describe their perceptions of its value. Using a qualitative, descriptive methodology, firefighters who had participated in a longitudinal lung function surveillance study were invited to participate in semi-structured interviews. Purposeful, maximum variation s ling was used to achieve ersity in those firefighters invited to participate. We used inductive content analysis to identify themes. Interviews with 15 firefighters identified 3 main themes: (i) practical experience of surveillance (administration, communication, workplace culture change, convenience, acceptability, and appeal) (ii) value of surveillance (lung health efficacy and control, social support, workplace management support/motivations, contribution to global firefighter health) and (iii) contribution of surveillance to health (occupational risk, relevance in the context of total health, workability, and fitness and future value). Practical and psychosocial facilitators and barriers to providing lung function surveillance in the fire service were identified. In addition to the personal benefits of detecting adverse lung health and allowing for medical intervention, factors known to positively influence firefighter workplace wellbeing, such as providing peace of mind, feedback on good work practices, motivation to utilize control measures, management commitment to health, and providing data to assist with global knowledge were valued aspects of longitudinal lung function surveillance.
Publisher: Human Kinetics
Date: 10-2015
Abstract: The purpose of this study was to test the reliability and validity of 2 standardized methods for calculating speed at the second lactate-threshold point (LT 2 ) based on the preexisting D max (LT D ) and modified D max (LT MOD ) procedures. 13 trained male road runners and triathletes completed 2 incremental laboratory running tests to determine LT 2 , followed by separate time trials (5, 10, 15 km) on an outdoor running track. Two new methods were proposed for calculating the speed at LT 2 : (1) the single standardized lactate threshold (LT SDs ) and (2) the paired standardized lactate threshold (LT SDp ) for quantifying changes over time. The LT SDs and LT SDp methods had high relative (ICC ≥ .98) and absolute (CV ≤ 1.9%) reliability in identifying the speed at LT 2 . The speed at LT2 according to the LT SDs and LT SDp methods had a strong correlation and was not different to the performance speed during the 10- and 15-km time trials (≤2.3% ρ c 0.8 P .05). The following natural logbased formula was created to estimate the percentage of LT 2 speed (using the LT SDs method) that could be sustained for events ~15–75 min: y = –7.256(ln x ) + 157.64, where y = %LT 2 speed, x = time-trial performance (s), and ln = natural log. The standardized methods are reliable for determining LT 2 . The LT SDs and LT SDp methods for calculating the speed at LT 2 from a near-maximal incremental test calculated speeds similar to those exhibited in 10- and 15-km running time trials. A prediction equation for estimating the percentage of LT 2 that can be sustained for events of ~15–75 min was generated.
Publisher: Elsevier
Date: 2007
Publisher: Routledge
Date: 11-09-2008
Publisher: Human Kinetics
Date: 2021
Abstract: Purpose : To determine the effect of biological maturation on athletic movement competency as measured using the Athletic Ability Assessment-6. Methods : Fifty-two junior Australian Rules football players were split into 3 groups based on proximity to peak height velocity, while 46 senior players were split into 2 groups based on playing status. The subjects completed the Athletic Ability Assessment-6 (inclusive of the overhead squat, double lunge, single-leg Romanian dead lift, push-up, and chin-up). All subjects were filmed and retrospectively assessed by a single rater. A 1-way analysis of variance and effect-size statistics (Cohen d ) with corresponding 90% confidence intervals were used to describe between-groups differences in the component movement scores. The statistical significance was set a priori at P .05. Results : There were significant between-groups differences for all component movements ( P .05). Post hoc testing revealed that older, more mature subjects possessed greater competency in all movements except the overhead squat. The effect sizes revealed predominantly moderate to very large differences in competency between the senior and junior groups (range of d [90% confidence interval]: 0.70 [0.06 to 1.30] to 3.01 [2.18 to 3.72]), with unclear to moderate differences found when comparing the 3 junior groups (0.08 [−0.50 to 0.65] to 0.97 [0.22–1.61]). Conclusions : The findings suggest that biological maturation may be associated with changes in athletic movement competency in youth Australian Rules football players. Therefore, it is recommended that strength and conditioning coaches monitor maturity status when working with 12- to 15-y-old players. This can allow for a comparison of an in idual’s athletic movement competency to maturity-based standards and help guide developmentally appropriate training programs.
Publisher: Springer Science and Business Media LLC
Date: 10-05-2014
DOI: 10.1007/S40279-014-0178-6
Abstract: Studies have demonstrated that longer-term heat acclimation training (≥8 heat exposures) improves physical performance. The physiological adaptations gained through short-term heat acclimation (STHA) training suggest that physical performance can be enhanced within a brief timeframe. The aim of this systematic review was to determine if STHA training (≤7 heat exposures) can improve physical performance in healthy adults. MEDLINE, PubMed, and SPORTDiscus™ databases were searched for available literature. Studies were included if they met the following criteria: STHA intervention, performance measure outcome, apparently healthy participants, adult participants (≥18 years of age), primary data, and human participants. A modified McMaster critical appraisal tool determined the level of bias in each included study. Eight papers met the inclusion criteria. Studies varied from having a low to a high risk of bias. The review identified aerobic-based tests of performance benefit from STHA training. Peak anaerobic power efforts have not been demonstrated to improve. At the review level, this systematic review did not include tolerance time exercise tests however, certain professions may be interested in this type of exercise (e.g. fire-fighters). At the outcome level, the review was limited by the moderate level of bias that exists in the field. Only two randomized controlled trials were included. Furthermore, a limited number of studies could be identified (eight), and only one of these articles focused on women participants. The review identified that aerobic-based tests of performance benefit from STHA training. This is possibly through a number of cardiovascular, thermoregulatory, and metabolic adaptations improving the perception of effort and fatigue through a reduction in anaerobic energy release and elevation of the anaerobic threshold. These results should be viewed with caution due to the level of available evidence, and the limited number of papers that met the inclusion criteria of the review. STHA training can be applied in the team-sport environment during a range of instances within the competitive season. A mixed high-intensity protocol may only require five sessions with a duration of 60 min to potentially improve aerobic-based performance in trained athletes.
Publisher: Human Kinetics
Date: 08-2014
Abstract: Many equations to predict maximal oxygen uptake (V̇O 2 max) from submaximal exercise tests have been proposed for young people, but the composition and accuracy of these equations vary greatly. The purpose of this systematic review was to analyze all submaximal exercise-based equations to predict V̇O 2 max measured via direct gas analysis for use with young people. Five databases were systematically searched in February 2013. Studies were included if they used a submaximal, exercise-based method to predict V̇O 2 max the actual V̇O 2 max was gas analyzed participants were younger than 18 years and equations included at least one submaximal exercise-based variable. A meta-analysis and narrative synthesis were conducted. Sixteen studies were included. The mean equation validity statistic was strong, r = .786 (95% CI 0.747–0.819). Subgroup meta-analysis suggests exercise mode may contribute to the overall model, with running- and walking-based predictive equations reporting the highest mean r values (running r = .880 walking r = .821) and cycling the weakest ( r = .743). Selection of the most appropriate equation should be guided by factors such as purpose, logistic limitations, appropriateness of the validation s le, the level of study bias, and the degree of accuracy. Suggestions regarding the most accurate equation for each exercise mode are provided.
Publisher: Wiley
Date: 09-1997
DOI: 10.1016/S1090-3801(97)90108-7
Abstract: Downhill running, particularly for the untrained subject, is a mode of eccentric exercise that produces delayed-onset muscle soreness (DOMS) in the quadriceps femoris muscle which is maximal between 24 and 72 h after the exercise. It is not clear whether sensitivity to pain is uniform over the surface of the muscle, or whether some locations become more sensitive following eccentric exercise. The purpose of this investigation was to compare pressure pain tolerance (PPTO) at various sites on the quadriceps femoris muscle on 2 days prior to exercise, immediately after, and at 24, 48 and 72 h following a bout of eccentric exercise. Fifteen untrained female subjects performed a 40 min downhill run on a motorized treadmill with a gradient of -12%, where running speed was adjusted to elicit a heart rate of approximately 60% of age-related maximum heart rate reserve, and were measured for PPTO at seven sites on the right thigh. Sites were visited sequentially three times and repeated on each of 6 days. Pressure pain tolerance as an index of tenderness was determined using a strain gauge algometer. Two sites were close to the distal myotendinous junction, three sites were located on the mid belly of the muscle and two sites were located at the proximal myotendinous junction. There was a significant difference (p<0.01) in PPTO between muscle sites prior to eccentric exercise (Days 1 and 2), and a significant difference between sites following eccentric exercise (p<0.01). Sites close to the distal and proximal myotendinous junction were most sensitive to pain (p<0.01). There was no difference in PPTO at any site across the belly of the muscle. These results suggest that the belly of the quadriceps femoris is the most suitable area for measurement of PPTO.
Publisher: Springer Science and Business Media LLC
Date: 06-1990
DOI: 10.1007/BF00666808
Publisher: Springer Science and Business Media LLC
Date: 12-1996
DOI: 10.1007/BF02595625
Publisher: Springer Science and Business Media LLC
Date: 10-2012
DOI: 10.1007/BF03262298
Publisher: Canadian Science Publishing
Date: 08-2008
DOI: 10.1139/H08-050
Abstract: The effects of inspiratory muscle (IM) training on maximal 20 m shuttle run performance (Ex) during Yo-Yo intermittent recovery test and on the physiological and perceptual responses to the running test were examined. Thirty men were randomly allocated to 1 of 3 groups. The experimental group underwent a 6 week pressure threshold IM training program by performing 30 inspiratory efforts twice daily, 6 d/week, against a load equivalent to 50% maximal static inspiratory pressure. The placebo group performed the same training procedure but with a minimal inspiratory load. The control group received no training. In post-intervention assessments, IM function was enhanced by % in the experimental group. The Ex was improved by 16.3% ± 3.9%, while the rate of increase in intensity of breathlessness (RPB/4i) was reduced by 11.0% ± 6.2%. Further, the whole-body metabolic stress reflected by the accumulations of plasma ammonia, uric acid, and blood lactate during the Yo-Yo test at the same absolute intensity was attenuated. For the control and placebo groups, no significant change in these variables was observed. In comparison with previous observations that the reduced RPB/4i resulting from IM warm-up was the major reason for improved Ex, the reduced RPB/4i resulting from the IM training program was lower despite the greater enhancement of IM function, whereas improvement in Ex was similar. Such findings suggest that although both IM training and warm-up improve the tolerance of intense intermittent exercise, the underlying mechanisms may be different.
Publisher: Wiley
Date: 07-07-2007
DOI: 10.1111/J.1469-8986.2007.00558.X
Abstract: This study assessed the relationship between the rate of change of the rating of perceived exertion (RPE), physiological activity, and time to volitional exhaustion. After completing a graded exercise test, 10 participants cycled at a constant load equating to 75% of peak oxygen uptake (V O(2)peak) to exhaustion. Participants performed two further constant load exercise tests at 75%V O(2)peak in a fresh state condition within the next 7 days. The RPE was regressed against time and percentage of the time (%time) to volitional exhaustion in both conditions. Despite a lower respiratory exchange ratio (RER) and higher heart rate at the start of the exercise bout in the fatigued condition, there were no differences in RPE at the onset or completion of exercise. As expected, the rate of increase in RPE was greater in the fatigued condition, but there were no differences when expressed against %time. Results suggest that RPE is set at the start of exercise using a scalar internal timing mechanism, which regulates RPE by altering the gain of the relationship with physiological parameters such as heart rate and RER when these are altered by previous fatiguing exercise.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 05-10-2016
DOI: 10.1007/S00421-016-3485-9
Abstract: To determine whether maximal oxygen uptake (VO Sixteen participants (31.7 ± 11.3 years, 3 females) completed three PRETs (separated by 24-72 h) and one maximal, perceptually-regulated, graded exercise test (PRETmax) on a motorized treadmill. Oxygen uptake (VO VO The step PRET elicited significant and reliable increases in VO
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2015
Publisher: Elsevier BV
Date: 11-1989
Publisher: Springer Science and Business Media LLC
Date: 09-1989
DOI: 10.2165/00007256-198908030-00004
Abstract: The nature and magnitude of the training effect is a function of the frequency, duration and intensity with which vigorous exercise is undertaken. The intensity dimension is a key element in producing changes in central cardiovascular haemodynamics, but because of a 'self-awareness' factor implicated in both the reporting and regulating the intensity level, the determination of this parameter is difficult. Contemporary research with psychophysical ratings of effort sense has led to the recommendation by the American College of Sports Medicine that the rating of perceived exertion is a useful device in the determination of exercise intensity. This paper presents a review of research related to the setting of exercise intensity from a psychophysiological standpoint, and includes a set of observations from research which has examined the influence of perceptual, cognitive and affective variables on the reporting of the rating of perceived exertion.
Publisher: Elsevier BV
Date: 08-1999
Publisher: Springer Science and Business Media LLC
Date: 06-2010
DOI: 10.1038/SC.2010.59
Abstract: Each participant completed an arm-crank r exercise test to volitional exhaustion. To assess the utility of the rating of perceived exertion (RPE) to predict peak oxygen uptake (VO(2)peak) during arm ergometry in able-bodied participants and those with poliomyelitis. University of Jordan, Amman, Jordan. In all, 16 able-bodied and 15 participants with poliomyelitis completed an arm-crank r exercise test to volitional exhaustion. The prediction of VO(2)peak is calculated by extrapolating the sub-maximal RPE and VO(2) values by linear regression to RPE 20. For the able-bodied participants, there were no significant differences between measured and predicted VO(2)peak from the three sub-maximal ranges of the RPE (RPEs before and including RPE 13, 15 and 17, P > 0.05). For the participants with poliomyelitis, the VO(2)peak predicted from RPEs before and including RPE 13 was significantly higher than measured VO(2)max (P < 0.05). The 95% limits of agreement of able-bodied participants for RPE 13, 15 and 17 (-3 ± 14, -1 ± 10 & 0 ± 8 ml kg(-1) min(-1), respectively) were lower than those observed for poliomyelitis participants (6 ± 19, 2 ± 12 and 1 ± 9 ml kg(-1) min(-1), respectively). This study has shown that the estimation of VO(2)peak from submaximal RPE during arm ergometry is generally more accurate in able-bodied participants in comparison with those with poliomyelitis.
Publisher: Springer Science and Business Media LLC
Date: 16-11-2012
DOI: 10.1007/S00421-012-2541-3
Abstract: The aim of this study was to assess the sensitivity of a perceptually regulated exercise test (PRET) to predict maximal oxygen uptake (VO₂max) following an aerobic exercise-training programme. Sedentary volunteers were assigned to either a training (TG n = 16) or control (CG n = 10) group. The TG performed 30 min of treadmill exercise, regulated at 13 on the Borg Rating of Perceived Exertion (RPE) Scale, 3× per week for 8 weeks. All participants completed a 12-min PRET to predict VO₂max followed by a graded exercise test (GXT) to measure VO₂max before and after training. The PRET required participants to control the speed and incline on the treadmill to correspond to RPE intensities of 9, 11, 13 and 15. Predictive accuracy of extrapolation end-points RPE19 and RPE20 from a submaximal RPE range of 9-15 was compared. Measured VO₂max increased by 17 % (p < 0.05) from baseline to post-intervention in TG. This was reflected by a similar change in [VO₂max predicted from PRET when extrapolated to RPE 19 (baseline VO₂max: 31.3 ± 5.5, 30.3 ± 9.5 mL kg(-1) min(-1) post-intervention VO₂max: 36.7 ± 6.4, 37.4 ± 7.9 mL kg(-1) min(-1), for measured and predicted values, respectively). There was no change in CG (measured vs. predicted VO₂max: 39.3 ± 6.5 40.3 ± 8.2 and 39.2 ± 7.0 37.7 ± 6.0 mL kg(-1) min(-1)) at baseline and post-intervention, respectively. The results confirm that PRET is sensitive to increases in VO₂max following aerobic training.
Publisher: Springer Science and Business Media LLC
Date: 24-11-2010
DOI: 10.1007/S00421-010-1722-1
Abstract: This study assessed the relationship between rating of perceived exertion (RPE) and time to exhaustion during arm cranking exercise while exercising at two different constant-load exercise intensities in able-bodied and paraplegic in iduals. The second aim of this study was to assess the rate of change in the RPE between the two different constant-load exercise intensities in absolute and relative terms. Ten able-bodied men and ten paraplegic men performed four exercise tests: (1) a r exercise test (started at 0 W and increased by 15 W min(-1)), (2) a graded exercise test (GXT) (started at 30 W and increased by 15 W every 2 min) these tests were performed in counterbalanced order, (3) a constant-load exercise test equal to 50% delta [i.e., the difference between the gas exchange threshold and peak power output (Δ)], (4) a constant-load exercise test equal to 70% Δ these tests were also performed in counterbalanced order. There was a strong linear relationship between the RPE and time to exhaustion (R (2) ≥ 0.88) irrespective of exercise intensity and participants' group. As expected, the rate of change in the RPE was significantly greater during 70% Δ compared to 50% Δ when the RPE was regressed against absolute time regardless of group. However, differences in the rate of change in the RPE were removed when the RPE was regressed against proportion of time, irrespective of group. These findings have important implications for predicting time to exhaustion while exercising at constant-load exercise intensity during arm cranking in able-bodied and paraplegic in iduals.
Publisher: Elsevier BV
Date: 05-1998
DOI: 10.1016/S0969-8043(97)00062-6
Abstract: The measurement of body fat in ten subjects (BMI from 22 to 43 kg/m2), and in particular the changes arising from a ketogenic diet, by the techniques of in vivo neutron activation analysis (NAA), densitometry (using two- and four-compartment models) by under water weighing (UWW) and dual energy X-ray absorptiometry (DXA) was compared. The association between techniques for the fat changes was generally high (r = 0.70 to 0.98) and significant (p < 0.05). Assessment of agreement between DXA and the other techniques revealed discrepancies with significant slope and high association (r = -0.81 and -0.64). Whilst NAA and UWW appeared to measure similar changes, DXA underestimated small changes.
Publisher: Springer Science and Business Media LLC
Date: 12-1989
DOI: 10.1007/BF00665445
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2011
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2010
Publisher: Springer Science and Business Media LLC
Date: 30-01-2018
Publisher: Public Library of Science (PLoS)
Date: 05-2014
Publisher: Elsevier BV
Date: 02-2002
Publisher: Springer Science and Business Media LLC
Date: 14-04-2015
DOI: 10.1007/S00221-015-4276-Y
Abstract: This study examined the effects of handedness on the inter-digit coordination of force variability with and without concurrent visual feedback during sustained precision pinch. Twenty-four right-handed subjects were instructed to pinch an instrumented apparatus with their dominant and non-dominant hands, separately. During the pinch, the subjects were required to maintain a stable force output at 5 N for 1 min. Visual feedback was given for the first 30 s and removed for the second 30 s. Coefficient of variation and detrended fluctuation analysis were employed to examine the amount and structural variability of the thumb and index finger forces. Similarly, correlation coefficient and detrended cross-correlation analysis were applied to quantify the inter-digit correlation of force amount and structural variability. Results showed that, compared to the non-dominant hand, the dominant hand had higher inter-digit difference in the amount of digit force variability. Without visual feedback, the dominant hand exhibited lower digit force structural variability but higher inter-digit force structural correlation than the non-dominant hand. These results implied that the dominant hand would be more independent, less flexible and with lower dynamic degrees of freedom than the non-dominant hand in coordination of the thumb and index finger forces during sustained precision pinch. The effects of handedness on inter-digit force coordination were dependent on sensory condition, which shed light on higher-level sensorimotor mechanisms that may be responsible for the asymmetries in coordination of digit force variability.
Publisher: Springer Science and Business Media LLC
Date: 02-06-2009
DOI: 10.1007/S00421-009-1093-7
Abstract: This study assessed the utility of a single, continuous exercise protocol in facilitating accurate estimates of maximal oxygen uptake V(O)(2max) from submaximal heart rate (HR) and the ratings of perceived exertion (RPE) in healthy, low-fit women, during cycle ergometry. Eleven women estimated their RPE during a continuous test (1 W 4 s(-1)) to volitional exhaustion (measured V(O)(2max)). In idual gaseous exchange thresholds (GETs) were determined retrospectively. The RPE and HR values prior to and including an RPE 13 and GET were extrapolated against corresponding oxygen uptake to a theoretical maximal RPE (20) and peak RPE (19), and age-predicted HRmax, respectively, to predict V(O)(2max)). There were no significant differences (P > 0.05) between measured (30.9 +/- 6.5 ml kg(-1) min(-1)) and predicted V(O)(2max) from all six methods. Limits of agreement were narrowest and intraclass correlations were highest for predictions of V(O)(2max) from an RPE 13 to peak RPE (19). Prediction of V(O)(2max) from a regression equation using submaximal HR and work rate at an RPE 13 was also not significantly different to actual V(O)(2max) (R( 2 ) = 0.78, SEE = 3.42 ml kg(-1) min(-1), P > 0.05). Accurate predictions of V(O)(2max) may be obtained from a single, continuous, estimation exercise test to a moderate intensity (RPE 13) in low-fit women, particularly when extrapolated to peak terminal RPE (RPE(19)). The RPE is a valuable tool that can be easily employed as an adjunct to HR, and provides supplementary clinical information that is superior to using HR alone.
Publisher: Human Kinetics
Date: 04-2015
Abstract: Peak oxygen uptake (V̇O 2 peak) is reliably predicted in young and middle-aged adults using a submaximal perceptually-regulated exercise test (PRET). It is unknown whether older adults can use a PRET to accurately predict V̇O 2 peak. In this study, the validity of a treadmill-based PRET to predict V̇O 2 peak was assessed in 24 participants (65.2 ± 3.9 years, 11 males). The PRET required a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13, and 15. Extrapolation of submaximal V̇O 2 from the PRET to RPE endpoints 19 and 20 and age-predicted HRmax were compared with measured V̇O 2 peak. The V̇O 2 extrapolated to both RPE19 and 20 over-predicted V̇O 2 peak ( p .001). However, extrapolating V̇O 2 to age-predicted HRmax accurately predicted V̇O 2 peak ( r = .84). Results indicate older adults can use a PRET to predict V̇O 2 peak by extrapolating V̇O 2 from submaximal intensities to an age-predicted HRmax.
Publisher: Public Library of Science (PLoS)
Date: 13-07-2017
Publisher: Informa UK Limited
Date: 02-1993
DOI: 10.1080/02640419308729957
Abstract: The assessment of frame size is a problematic and ambiguous area. The purpose of this study was to assess the level of agreement between various techniques of assessing frame size in a group of 27 healthy and active men aged 18-24 years, and also to assess which anthropometric variables were best associated with a measure of actual frame size (AFS) which is proposed in this study. Actual frame size was measured by the summation of a series of bone breadths, lengths and depths on a sub-s le of 17 men. The results of the study revealed substantial discordance between methods of assessing frame size. The variables which correlated most highly with AFS (P < 0.01) were body mass, ankle breadth, hand length and chest breadth, respectively. These variables were also positively correlated (P < 0.01) with fat-free mass (FFM), with no significant correlation with fat mass in either case. Of the various documented methods used to assess frame size, the 'HAT' technique, which incorporates biacromial and bitrochanteric breadths, was more highly correlated with AFS than both elbow breadth (currently used in height-weight insurance tables) and the height/wrist circumference index. The latter measure was not highly correlated with AFS, body mass and FFM in this study. It was concluded that ankle breadth and hand length may be better predictors of frame size in young men than other bone dimensions. In addition, the results of this preliminary investigation have substantiated the potential viability of an AFS model. Future research using this technique is recommended to determine true indicators of frame size in a larger and more heterogeneous population.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2004
DOI: 10.1249/01.MSS.0000117158.14542.E7
Abstract: The aims of this study were to assess and compare the validity of the RT3 accelerometer for the assessment of physical activity in boys and men, to compare RT3 and Tritrac accelerometer counts, and to determine count cut-off values for moderate (> or =3 or =6 METs) activity. Nineteen boys (age: 9.5 +/- 0.8 yr) and 15 men (age: 20.7 +/- 1.4 yr) walked and ran on a treadmill, kicked a ball to and fro, played hopscotch, and sat quietly. An RT3 was worn on the right hip boys also wore a Tritrac on the left hip. Oxygen consumption was expressed as a ratio of body mass raised to the power of 0.75 (S VO2). RT3 counts correlated significantly with S VO2 in boys (r = 0.87, P < 0.01) and men (r = 0.85, P < 0.01). However, during treadmill activities, RT3 counts were significantly higher for boys (P < 0.05). RT3 counts corresponding to "moderate" and "vigorous" activity were similar for boys and men for all activities (moderate = 970.2 for boys and 984.0 for men vigorous = 2333.0 for boys and 2340.8 for men) but approximately 400 counts lower in men when only treadmill activities were considered. Tritrac counts correlated significantly with S VO2 in boys (r = 0.87, P < 0.01), but were significantly lower than RT3 counts across most activities (P < 0.05). The RT3 accelerometer is a good measure of physical activity for boys and men. However, moderate and vigorous intensity count thresholds differ for boys and men when the predominant activities are walking and running. RT3 counts are significantly higher than Tritrac counts for a number of activities. These findings have implications when comparing activity counts between studies using the different instruments.
Publisher: Informa UK Limited
Date: 07-1996
Publisher: Informa UK Limited
Date: 05-2000
Publisher: Informa UK Limited
Date: 2009
DOI: 10.3109/17477160902846179
Abstract: Spontaneous and transitory movement patterns are characteristic of children. The aim of this study was to explore the relationship between short, frequent activity bouts and children's health. Physical activity was recorded every 2 s by accelerometry (ActiGraph GT1M) for seven days in 47 boys (age 8-10 years). Summary activity measures and activity pattern characteristics (frequency, intensity and duration of > or = 4 s [short] and > or = 5 min [long] bouts of > or= light [> or = LIGHT], > or = moderate [> or = MOD], > or = vigorous [> or = VIG], and > or = hard [> or = HARD] intensity activity) were recorded. Microvascular function was assessed using laser Doppler perfusion imaging as the forearm skin blood flow response to the iontophoretic application of acetylcholine (endothelial dependent vasodilator) and sodium nitroprusside (endothelial independent vasodilator) at rest and following maximal exercise. Waist circumference, resting blood pressure and aerobic fitness (VO(2peak)) were measured. The intensity of short and long > or = LIGHT bouts and the frequency of short and long > or =MOD bouts were correlated with waist circumference (r = - 0.42 to -0.52, p < 0.01) and VO(2peak) (r = 0.42 to 0.47, p or =LIGHT bouts were associated with change in endothelial function from rest to post-exercise (r = 0.34 to 0.55, p or =4 s) of activity and health was as strong as relationships identified between longer bouts (> or =5 min) and health. This is encouraging as sporadic intermittent activity is characteristic of children's activity pattern.
Publisher: Informa UK Limited
Date: 04-2009
DOI: 10.1080/00140130802707691
Abstract: The purpose of this study was to compare ratings of perceived exertion (RPE Borg's 6-20 scale) at the same exercise intensity, between a standard exercise electrocardiogram (ECG) treadmill stress test (exECG) and two subsequent bouts of treadmill exercise in a cardiac rehabilitation gymnasium. Eleven patients (mean +/- s) 60.8 +/- 6.1 years performed an exECG within 12.1 +/- 7.5 d after myocardial infarction (MI) and commenced their first exercise-based rehabilitation session (gym-1), which included the use of a motorised treadmill, within 5.0 +/- 1.3 d after the exECG. A second gym session (gym-2) was performed within 4.2 +/- 1.3 d of gym-1. Gym-1 and gym-2 treadmill exercise was performed at an intensity that equated to the penultimate testing stage of exECG, and RPE and heart rate were compared at this level between the three sessions of testing. The mean work rate at the penultimate testing stage of the exECG was 6.0 +/- 1.0 metabolic equivalents approximately 67% of peak work rate. The RPE at this work rate during exECG, gym-1 and gym-2 were 15.8 +/- 2.7, 13.3 +/- 3.4 and 13.0 +/- 3.6, respectively. A repeated measures ANOVA revealed these RPE responses to be significantly different (F (2, 20) = 9.8 p = 0.001). Post-hoc Bonferroni-corrected pairwise t-tests showed significant differences (p < or = 0.008) between exECG and gym-1 and exECG and gym-2 but not between gym-1 and gym-2. There was no significant difference in heart rate between the three testing sessions (p = 0.076) but it showed signs of a similar trend to RPE. The intra-participant agreement in RPE between gym-1 and gym-2 was substantial intraclass correlation coefficient (ICC(2,1)) = 0.85 (p < 0.001) and in all but one participant, RPE differed by < or =2 scale points. The RPE responses during standardised exECG treadmill testing, in patients soon after MI, are inflated compared to responses at the same treadmill work rate during subsequent cardiac rehabilitation exercise sessions. Caution is advised in using RPE taken from an initial exECG to guide physical activity in MI patients, but introducing RPE at this point contributes to its subsequent reliable use.
Publisher: Informa UK Limited
Date: 07-2019
Publisher: Informa UK Limited
Date: 2001
DOI: 10.1080/026404101753113822
Abstract: The length-tension relationship of muscle contraction is well documented in adults. However, research on this relationship in children has been limited. The aim of this study was to compare differences in the torque-joint angle relationship of the quadriceps muscle in children and adults. Eight boys aged 8-10 years and eight men aged 20-26 years performed two maximal voluntary isometric contractions at six knee joint angles (20 degrees, 40 degrees, 60 degrees, 80 degrees, 90 degrees, 100 degrees). The mean of the two trials was used as the performance measure. Both groups demonstrated an expected increase in relative torque as the joint angle increased (P< 0.05). The men produced significantly greater relative torque at 20 degrees, 40 degrees and 60 degrees knee flexion (P < 0.05). The percentage of maximal torque at these angles for the men and boys respectively were: 35.2+/-4.3 vs 15.2+/-12%, 63.6+/-9.1 vs 51.8+/-16.8% and 93.6+/-6.5 vs 84.4+/-14.4%. There were no group differences at 80 degrees or 90 degrees. Peak torque was attained at 80 degrees in men, but decreased significantly (P< 0.05) at 90 degrees and 100 degrees. For boys, peak torque was attained at joint angles of 80 degrees and 90 degrees. The reduction in peak torque at 100 degrees was not statistically significant, but the relative torque at this angle was lower in men than in boys (77.9+/-13.7 vs 87.1+/-10.4% P< 0.05). In conclusion, the relationship between torque and joint angle appears to be affected by age.
Publisher: Elsevier BV
Date: 12-2012
Publisher: Informa UK Limited
Date: 07-2012
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.JELEKIN.2008.07.002
Abstract: This study documents intra-session and inter-day reproducibility (coefficient of variation [V%]) and single measurement reliability (intra-class correlations [R(I)] standard error of a single measurement [SEM%] [95% confidence limits]) of indices of neuromuscular performance elicited during peripheral nerve magnetic stimulation. Twelve adults (five men and seven women) completed 3 assessment sessions on 3 days, during which multiple assessments of knee flexor volitional and magnetically-evoked indices of electromechanical delay (EMD(V) EMD(E)), rate of force development (RFD(V) RFD(E)), peak force (PF(V) P(T)F(E)), and compound muscle action potential latency (LAT(E)) and litude (AMP(E)) were obtained. Results showed that magnetically-evoked indices of neuromuscular performance offered statistically equivalent levels of measurement reproducibility (V%: 4.3-31.2%) and reliability (R(I): 0.98-0.51) compared to volitional indices (V%: 3.7-25.2% R(I): 0.98-0.64), which support the efficacy of both approaches to assessment and the indices PF(V), EMD(V), EMD(E) and LAT(E) offer the greatest practical utility for assessing neuromuscular performance.
Publisher: Springer Science and Business Media LLC
Date: 11-04-2011
DOI: 10.1007/S00421-011-1957-5
Abstract: This study tested the effects of low-cadence (60 rev min(-1)) uphill (Int(60)) or high-cadence (100 rev min(-1)) level-ground (Int(100)) interval training on power output (PO) during 20-min uphill (TT(up)) and flat (TT(flat)) time-trials. Eighteen male cyclists ([Formula: see text]: 58.6 ± 5.4 mL min(-1) kg(-1)) were randomly assigned to Int(60), Int(100) or a control group (Con). The interval training comprised two training sessions per week over 4 weeks, which consisted of six bouts of 5 min at the PO corresponding to the respiratory compensation point (RCP). For the control group, no interval training was conducted. A two-factor ANOVA revealed significant increases on performance measures obtained from a laboratory-graded exercise test (GXT) (P (max): 2.8 ± 3.0% p < 0.01 PO and [Formula: see text] at RCP: 3.6 ± 6.3% and 4.7 ± 8.2%, respectively p < 0.05 and [Formula: see text] at ventilatory threshold: 4.9 ± 5.6% p < 0.01), with no significant group effects. Significant interactions between group and uphill and flat time-trial, pre- versus post-training on PO were observed (p < 0.05). Int(60) increased PO during both TT(up) (4.4 ± 5.3%) and TT(flat) (1.5 ± 4.5%). The changes were -1.3 ± 3.6, 2.6 ± 6.0% for Int(100) and 4.0 ± 4.6%, -3.5 ± 5.4% for Con during TT(up) and TT(flat), respectively. PO was significantly higher during TT(up) than TT(flat) (4.4 ± 6.0 6.3 ± 5.6% pre and post-training, respectively p < 0.001). These findings suggest that higher forces during the low-cadence intervals are potentially beneficial to improve performance. In contrast to the GXT, the time-trials are ecologically valid to detect specific performance adaptations.
Publisher: Springer Science and Business Media LLC
Date: 11-08-2007
DOI: 10.1007/S00421-007-0536-2
Abstract: This study assessed the relationship between differentiated ratings of perceived exertion (RPE) and heart rate with oxygen uptake (VO2) during two graded exercise tests (GXT) to exhaustion on a cycle ergometer in 49 men and women (19-50 years) of high and low fitness. The study also assessed whether sub-maximal RPE values elicited during the GXTs could provide appropriate estimates of maximal aerobic power (VO2max) Peripheral RPE (RPEP) was higher than overall RPE (RPEO) at exhaustion in both groups (P 0.05). However, the correlation for RPEP and VO2 was higher for women compared to men (0.98 and 0.96, respectively, P<0.05), although this is of little practical significance. In both groups, RPEO was almost as highly correlated with VO2 as heart rate during GXTs terminated at exhaustion (approximately 0.955-0.980). There were no differences between predicted and measured VO2max when VO2 values were extrapolated from sub-maximal RPEO (13, 15 and 17) intensities (42.1+/-12.5, 43.4+/-11.5, 44.2+/-11.3 and 43.3+/-10.0 ml kg(-1) min(-1), respectively). However, VO2max predicted from sub-maximal RPEP intensities was significantly lower (P<0.05). In conclusion, terminal RPEO was a more reliable measure of the RPE, and provided more accurate estimates of VO2max in healthy participants of high and low fitness when elicited from sub-maximal exercise intensities.
Publisher: Informa UK Limited
Date: 04-2009
DOI: 10.1080/00140130802707733
Abstract: The purpose of this study was to examine the effectiveness of a single bout of cold-water immersion on recovery from exercise-induced muscle damage. Eighteen physically active female volunteers (age 19.9 (+/-0.97 years), height 1.66 (+/-0.05 m), mass 63.7 (+/-10 kg), completed 10 sets of 10 counter-movement jumps to induce muscle damage and were randomly allocated to a control or treatment group. The treatment group was given a single 10-min bout of lower limb cold-water immersion therapy at 10 degrees C immediately following damage-inducing exercise. Indicators of muscle damage (plasma creatine kinase activity, perceived soreness and maximal voluntary contraction of the quadriceps) were assessed immediately prior to counter-movement jumps, and at 1, 24, 48, 72 and 96 h, following the damaging exercise. Significant (p = 0.05) time effects were recorded on all indicators of muscle damage, but there were no significant group or group x time interaction effects found on any of the measured variables. The results indicate that a single bout of cold-water immersion after a damaging bout of exercise has no beneficial effects on the recovery from exercise-induced muscle damage.
Publisher: Springer Science and Business Media LLC
Date: 1999
DOI: 10.2165/00007256-199927030-00002
Abstract: Unfamiliar, predominantly eccentric exercise, frequently results in muscle damage. A repeated bout of similar eccentric exercise results in less damage and is referred to as the 'repeated bout effect'. Despite numerous studies that have clearly demonstrated the repeated bout effect, there is little consensus as to the actual mechanism. In general, the adaptation has been attributed to neural, connective tissue or cellular adaptations. Other possible mechanisms include, adaptation in excitation-contraction coupling or adaptation in the inflammatory response. The 'neural theory' predicts that the initial damage is a result of high stress on a relatively small number of active fast-twitch fibres. For the repeated bout, an increase in motor unit activation and/or a shift to slow-twitch fibre activation distributes the contractile stress over a larger number of active fibres. Although eccentric training results in marked increases in motor unit activation, specific adaptations to a single bout of eccentric exercise have not been examined. The 'connective tissue theory' predicts that muscle damage occurs when the noncontractile connective tissue elements are disrupted and myofibrillar integrity is lost. Indirect evidence suggests that remodelling of the intermediate filaments and/or increased intramuscular connective tissue are responsible for the repeated bout effect. The 'cellular theory' predicts that muscle damage is the result of irreversible sarcomere strain during eccentric contractions. Sarcomere lengths are thought to be highly non-uniform during eccentric contractions, with some sarcomeres stretched beyond myofilament overlap. Loss of contractile integrity results in sarcomere strain and is seen as the initial stage of damage. Some data suggest that an increase in the number of sarcomeres connected in series, following an initial bout, reduces sarcomere strain during a repeated bout and limits the subsequent damage. It is unlikely that one theory can explain all of the various observations of the repeated bout effect found in the literature. That the phenomenon occurs in electrically stimulated contractions in an animal model precludes an exclusive neural adaptation. Connective tissue and cellular adaptations are unlikely explanations when the repeated bout effect is demonstrated prior to full recovery, and when the fact that the initial bout does not have to cause appreciable damage in order to provide a protective effect is considered. It is possible that the repeated bout effect occurs through the interaction of various neural, connective tissue and cellular factors that are dependent on the particulars of the eccentric exercise bout and the specific muscle groups involved.
Publisher: MDPI AG
Date: 03-2016
Publisher: Springer Science and Business Media LLC
Date: 05-11-2021
DOI: 10.1007/S40279-021-01584-W
Abstract: Little is known about which indicators of performance elite athlete coaches (i.e., professional coaches who coach at the national or international levels) consider to be important for basketball. Using a Delphi procedure, the aim of this study was to identify the non-game performance indicators elite athlete coaches consider to be important for the recruitment/selection of basketball players. Ninety elite athlete coaches (basketball coaches (n = 71) and strength/conditioning coaches (n = 19) who coached men (n = 60), women (n = 23), or both (n = 7)), employed in 23 countries across six continents, participated in a three-round online Delphi survey. Round 1 asked coaches to identify the non-game performance indicators (i.e., measures other than game statistics) they currently used (or would like to use) for player recruitment/selection, with common indicators combined into single indicators. Round 2 asked coaches to rate the importance of each performance indicator using a Likert scale (range: 0 = no importance whatsoever to 10 = extremely important). Round 3 asked coaches to identify the single best test measure for each indicator rated ≥ 6 (i.e., important to extremely important) in Round 2. Results were reported descriptively. A total of 608 responses (344 after removal of duplicates) were reported in Round 1, which were collapsed into 35 indicators, all of which were rated as 'important' in Round 2. Psychological and game intelligence indicators were typically rated as very important to extremely important (i.e., median = 9), with physical fitness and movement skills typically rated as very important (i.e., median = 8). For most indicators, coach observation was identified as the best test measure, with unique objective performance/anthropometric tests identified for all physical fitness indicators. This study identified a range of psychological, game intelligence, physical fitness, and movement skill indicators that were considered by elite athlete coaches to be important to extremely important for the recruitment/selection of basketball players. These findings may inform the development of a basketball-specific test battery for recruiting/selecting and monitoring players.
Publisher: Wiley
Date: 03-01-2012
DOI: 10.1111/J.1469-8986.2011.01330.X
Abstract: Effects of deception and expected duration on the rating of perceived exertion (RPE), affect, and heart rate (HR) were examined during treadmill (n=12) and cycling (n=8) exercise. Participants completed three conditions: (1) 20 MIN-exercise for 20 min, stop after 20 min (2) 10 MIN-exercise for 10 min, in 10th min be told to exercise for 10 min more and (3) UNKNOWN-no information about duration. Intensities were set at 70% and 65% of peak oxygen uptake for treadmill and cycling, respectively. RPE increased (treadmill) and affect decreased (treadmill and cycling) in the absence of changes in HR and oxygen uptake in the 10 MIN conditions. These changes suggest a disruption to a feed-forward/feedback system. The lower HR in the UNKNOWN conditions suggests a subconscious attempt to conserve energy when the duration of the exercise task is unknown.
Publisher: Human Kinetics
Date: 05-2019
Abstract: Purpose : To compare the sensitivity of a submaximal run test (SRT) with a countermovement-jump test (CMJ) to provide an alternative method of measuring neuromuscular fatigue (NMF) in high-performance sport. Methods : A total of 23 professional and semiprofessional Australian rules football players performed an SRT and CMJ test prematch and 48 and 96 h postmatch. Variables from accelerometers recorded during the SRT were player load 1D up (vertical vector), player load 1D side (mediolateral vector), and player load 1D forward (anteroposterior vector). Meaningful difference was examined through magnitude-based inferences (effect size [ES]), with reliability assessed as typical error of measurements expressed as coefficient of variance. Results : A small decrease in CMJ height, ES −0.43 ± 0.39 (likely), was observed 48 h postmatch before returning to baseline 96 h postmatch. This was accompanied by corresponding moderate decreases in the SRT variables player load 1D up, ES −0.60 ± 0.51 (likely), and player load 1D side, ES −0.74 ± 0.57 (likely), 48 h postmatch before also returning to prematch baseline. Conclusion : The results suggest that in the presence of NMF, players use an alternative running profile to produce the same external output (ie, time). This indicates that changes in accelerometer variables during an SRT can be used as an alternative method of measuring NMF in high-performance Australian rules football and provides a flexible option for monitoring changes in the recovery phase postmatch.
Publisher: Elsevier BV
Date: 12-2011
Publisher: Informa UK Limited
Date: 09-1984
Publisher: American Physiological Society
Date: 11-2008
DOI: 10.1152/JAPPLPHYSIOL.90743.2008
Abstract: Unaccustomed eccentric exercise has a profound impact on muscle structure and function. However, it is not known whether associated microvascular dysfunction disrupts the matching of O 2 delivery (Q̇o 2 ) to O 2 utilization (V̇o 2 ). Near-infrared spectroscopy (NIRS) was used to test the hypothesis that eccentric exercise-induced muscle damage would elevate the muscle Q̇o 2 :V̇o 2 ratio during severe-intensity exercise while preserving the speed of the V̇o 2 kinetics at exercise onset. Nine physically active men completed “step” tests to severe-intensity exercise from an unloaded baseline on a cycle ergometer before (Pre) and 48 h after (Post) eccentric exercise (100 squats with a load corresponding to 70% of body mass). NIRS and breath-by-breath pulmonary V̇o 2 were measured continuously during the exercise tests and subsequently modeled using standard nonlinear regression techniques. There were no changes in phase II pulmonary V̇o 2 kinetics following the onset of exercise (time constant: Pre, 25 ± 4 s Post, 24 ± 2 s litude: Pre, 2.36 ± 0.23 l/min Post, 2.37 ± 0.23 l/min all P 0.05). However, the primary (Pre, 14 ± 3 s Post, 19 ± 3 s) and overall (Pre, 16 ± 4 s Post, 21 ± 4 s) mean response time of the [HHb] response was significantly slower following eccentric exercise ( P 0.05). The slower [HHb] kinetics observed following eccentric exercise is consistent with an increased Q̇o 2 :V̇o 2 ratio during transitions to severe-intensity exercise. We propose that unchanged primary phase V̇o 2 kinetics are associated with an elevated Q̇o 2 :V̇o 2 ratio that preserves blood-myocyte O 2 flux.
Publisher: Springer Science and Business Media LLC
Date: 30-03-2005
Abstract: To investigate the relationship of percent body fat (%fat), assessed by dual energy-X-ray absorptiometry (DXA) or a four-compartment model, with upper body and lower limb skinfolds. Cross-sectional design involving forward stepwise and hierarchical multiple regression analyses to assess the relationship of %fat with skinfolds and a combination of four commonly used upper body skinfolds (biceps, triceps, subscapular and iliac crest) with the calf and thigh skinfolds. University research laboratory. In all, 31 females, mean age 20.9 (+/-2.0) y, and 21 males, mean age 22.3 (+/-5.5) y volunteered for this study, which was approved by the Ethics Committee of the School of Sport, Health and Exercise Sciences, University of Wales, Bangor. %fat from DXA in both groups, and %fat from a four-compartment (water, bone mineral mass, fat and residual) model (%fat4C) in females only. Skinfolds were measured at the abdomen, iliac crest, biceps, triceps, subscapular, calf and thigh. All skinfolds were positively associated with DXA estimates of %fat (P < 0.01). In males and females, the thigh skinfold had the highest correlation with %fat. This was also observed when %fat4C was used as the criterion in females. Stepwise multiple regression analysis using %fatDXA as the criterion selected the thigh (R(2) = 0.82), calf (R(2) change 0.04) and iliac crest (R(2) change = 0.03) for females, and the thigh (R(2) = 0.79), iliac crest (R(2) change = 0.11) and abdomen (R(2) change = 0.03) for males (all P < 0.01). When %fat4C was used as the criterion in the females, only the thigh was selected as a significant predictor (R(2) = 0.76). Independent prediction factors were created from the sum of biceps, triceps, subscapular and iliac crest (sigma4skf) and from the sum of the thigh and calf (sigmathigh + calf). These factors were then entered into a hierarchical multiple linear regression analysis to predict percent fat. Order of entry was varied to allow the assessment of unique variance accounted for by each predictor. The sum of the thigh and calf explained more variance in %fatDXA than that explained by the sigma4skf alone, irrespective of the order of entry in both males and females. This was also observed when %fat4C was used as the criterion in the females. The results of this study confirm that lower body skinfolds are highly related to percent body fat in fit and healthy young men and women, and uphold current recommendations by the British Olympic Association to include the thigh skinfold with sigma4skf. Conventional use of the sigma4skf to estimate percent body fat is significantly enhanced by the inclusion of the thigh and calf skinfolds, either independently or in combination. In this group of males and females, the sum of the thigh and calf skinfolds accounted for the most variance in percent fat.
Publisher: Informa UK Limited
Date: 15-09-2005
DOI: 10.1080/00140130500101007
Abstract: The purpose of the present study was to ascertain whether differences existed in the regional placement of bone mineral mass (BMM), fat mass (FM) and lean soft tissue mass (LSTM) between playing units in Rugby Union Football and between players and control subjects. Thirty young adult rugby players and 21 controls participated in the study. Players were assigned to groups as either forwards (n = 15) or backs (n = 15). Control subjects were matched (n = 15) to rugby players using the mean BMI of forwards and backs. BMM, FM and LSTM were measured using dual-energy X-ray absorptiometry. The digital image of each subject was partitioned into regional anatomical segments comprising the head, right and left arms, trunk, and right and left legs. Measurements were summed for the arms and legs respectively. One-way ANOVA was used to differentiate between- and within-groups Tukey's post-hoc test was applied to identify pairwise differences. The alpha level was set throughout at p = 0.01. Principal components analysis was utilized to contrast the regional segments of each tissue in each of the groups. Forwards exhibited larger absolute (kg) amounts of BMM, FM and LSTM than backs or controls. In relative terms (%) there were no significant differences in BMM(%) between forwards, backs and controls in the arms and legs, but differences did occur between backs and controls at the trunk (2.9 vs. 2.5%). Backs had a significantly larger LSTM(%) than forwards at the arms (84.4 vs. 76.5%), legs (80.0 vs. 71.9%) and trunk (89.2 vs. 79.0%), whereas forwards had a greater FM(%) than backs at the arms (18.7 vs. 10.6%), legs (23.1 vs. 14.7%), and trunk (18.4 vs. 8.0%). The distribution of BMM showed a lower body-upper body contrast in forwards, a trunk-extremity contrast in backs and an arm-lower body contrast in controls. FM exhibited a trunk-extremity contrast in all three groups, while LSTM displayed an arm-lower body contrast in all three groups. It is concluded that there are significant regional tissue differences between forwards and backs, which may be related to playing function, and also differences between rugby players and controls.
Publisher: BMJ
Date: 02-2000
DOI: 10.1136/BJSM.34.1.59
Abstract: We have considered some of the most important factors involved in designing a viable study that will adequately address the research question. Although we do not profess to be experts in all aspects of the above, we have learned through experience that attention to many of the above points will help to avoid frustration during the experimental process and when the study is presented for external review and subsequent presentation and publication. Good luck in your research.
Publisher: Springer Science and Business Media LLC
Date: 08-08-2007
DOI: 10.1007/S00421-007-0508-6
Abstract: This study assessed whether the accuracy of predicting maximal oxygen uptake (VO2max) from sub-maximal heart rate (HR) and ratings of perceived exertion (RPE) values was moderated by gender and habitual activity. In total, 27 men and 18 women completed two GXTs to determine VO2max and three perceptually-regulated GXTs, incremented by RPE 9, 11, 13, 15 and 17. The RPE and HR were in idually regressed against VO2max (approximately 0.96) to enable predictions of VO2max. The VO2max was predicted from three RPE ranges (9-17, 9-15, 9-13). The RPE ranges were extrapolated to RPE(19), RPE(20) and age-predicted maximal HR (HRmax(pred)). ANOVA revealed no differences between measured and predicted VO2max (P > 0.05) when the RPE range 9-17 was extrapolated to RPE(19) and HRmax(pred). Extrapolation of RPE 9-17 to RPE(20) overestimated VO2max (P < 0.05), but no differences were observed when predicted from the RPE ranges 9-15 and 9-13. The prediction of VO2max was not moderated by gender or activity status. Hierarchical regression analysis revealed that HR explained additional variance in VO2max when added to the RPE (2%). Hierarchical multiple regression analysis also indicated that VO2max was significantly correlated with power output at sub-maximal RPE values of 13 and 15 (P < 0.01) in men and women. The addition of HRmax(pred) improved the accuracy of the prediction equation for men (P = 0.05) but not for women. The study confirmed the validity of estimating VO2max from perceptually-regulated, sub-maximal GXT and indicated the potential utility of regression analysis to gauge appropriate sub-maximal exercise intensities.
Publisher: Springer Science and Business Media LLC
Date: 07-04-2005
DOI: 10.1007/S00421-005-1327-2
Abstract: The purpose of this study was to assess the validity of predicting maximal oxygen uptake(VO(2max)) from sub-maximal VO(2) values elicited during a perceptually-regulated exercise test. We hypothesised that the strong relationship between the ratings of perceived exertion (RPE) and VO(2) would enable VO(2max) to be predicted and that this would improve with practice. Ten male volunteers performed a graded exercise test (GXT) to establish VO(2max) followed by three sub-maximal RPE production protocols on a cycle ergometer, each separated by a period of 48 h. The perceptually-regulated trials were conducted at intensities of 9, 11, 13, 15 and 17 on the RPE scale, in that order. VO(2) and HR were measured continuously and recorded at the end of each 4 min stage. In idual's RPE values yielded correlations in the range 0.92-0.99 across the three production trials. There were no significant differences between measured VO(2max) (48.8 ml.kg(-1).min(-1)) and predicted VO(2) max values (47.3, 48.6 and 49.9 ml.kg(-1).min(-1), for trials 1, 2 and 3, respectively) when VO(2) max was predicted from RPE values of 9-17. The same was observed when VO(2max) was predicted using RPE 9-15. Limits of agreement (LoA) analysis on actual and predicted VO(2max) values (from RPE 9-17) were (bias+/-1.96xSDdiff) 1.5+/-7.3, 0.2+/-4.9 and -1.2+/-5.8 ml.kg(-1).min(-1), for trials 1, 2 and 3, respectively. Corresponding LoA values for actual and predicted VO(2max) (from RPE 9-15) were 5.4+/-11.3, 4.4+/-8.7 and 2.3+/-8.4 ml.kg(-1).min(-1), respectively. The data suggest that a sub-maximal, perceptually-guided, graded exercise protocol can provide acceptable estimates of maximal aerobic power, which are further improved with practice in fit young males.
Publisher: Informa UK Limited
Date: 2001
DOI: 10.1080/026404101317015429
Abstract: Research into the physiology of exercise and kinanthropometry is intended to improve our understanding of how the body responds and adapts to exercise. If such studies are to be meaningful, they have to be well designed and analysed. Advances in personal computing have made available statistical analyses that were previously the preserve of elaborate mainframe systems and have increased opportunities for investigation. However, the ease with which analyses can be performed can mask underlying philosophical and epistemological shortcomings. The aim of this review is to examine the use of four techniques that are especially relevant to physiological studies: (1) bivariate correlation and linear and non-linear regression, (2) multiple regression, (3) repeated-measures analysis of variance and (4) multi-level modelling. The importance of adhering to underlying statistical assumptions is emphasized and ways to accommodate violations of these assumptions are identified.
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.APMR.2010.10.017
Abstract: To assess the accuracy of predicting peak oxygen consumption (Vo(2)peak) from a graded exercise test (GXT) and a r exercise test during arm exercise in able-bodied persons and persons with paraplegia using ratings of perceived exertion (RPEs). Each participant performed a GXT (started at 30W and increased by 15W every 2min) and a r exercise test (started at 0W and increased by 15W·min(-1)). Universities' laboratories. Able-bodied men (n=13 mean ± SD, 27.2±4.3y) and men with paraplegia (n=12 31.1±5.7y). Six of the persons with paraplegia had flaccid paralysis as a result of poliomyelitis infection. The other 6 persons had complete spinal cord injuries with neurologic levels at and below T6. Not applicable. Prediction of Vo(2)peak by extrapolating submaximal oxygen consumption (Vo(2)) and RPE values to RPE 20 on the Borg 6 to 20 RPE scale. This study showed a very strong linear relationship between RPE and Vo(2) during the GXT and the r test for able-bodied persons (R(2)≥.95 and R(2)≥.96, respectively) and persons with paraplegia (R(2)≥.96 and R(2)≥.95, respectively). There was no significant difference between measured and predicted Vo(2)peak from RPEs before and including RPE 13, 15, and 17 during the GXT for persons with paraplegia (P>.05). For the able-bodied participants, there was no significant difference between measured and predicted Vo(2)peak from RPEs before and including RPE 15 and 17 during the r exercise test (P>.05). The GXT provided acceptable predictions of Vo(2)peak for persons with paraplegia, and the r test provided acceptable predictions of Vo(2)peak for able-bodied persons.
Publisher: American Physiological Society
Date: 09-2005
DOI: 10.1152/JAPPLPHYSIOL.01193.2004
Abstract: The purpose of this study was to compare symptoms of exercise-induced muscle damage after an initial and repeated bout of plyometric exercise in men and boys. Ten boys (9–10 yr) and 10 men (20–29 yr) completed two bouts of eight sets of 10 plyometric jumps, 2 wk apart. Perceived soreness (0–10, visual analog scale), isometric strength of the quadriceps at six knee flexion angles, and countermovement jump and squat jump height were assessed before and at 30 min, 24 h, 48 h, and 72 h after each bout. All variables followed the expected patterns of change in men, with soreness peaking at 24–48 h (5.8 ± 1.7) and decrements in muscle function peaking at 30 min after the first bout (73–85% of baseline scores). Symptoms remained for 72 h after the first bout in men. In boys, symptoms were much less severe and peaked at 30 min (visual analog scale = 2.1 ± 1.8, functional decrements 87–92% of baseline) and, with the exception of soreness, returned to baseline after 24 h. After the second bout of plyometric exercise, the level of soreness and decrements in countermovement jump, squat jump, and isometric strength were lower, although the effect was stronger in men, in all cases. The results of this study suggest that although children may experience symptoms of muscle damage after intensive plyometric exercise, they are much less severe. A prior bout of plyometric exercise also appears to provide children with some protection from soreness after a subsequent bout of plyometric exercise. Explanations for milder symptoms of exercise-induced muscle damage in children include greater flexibility leading to less overextension of sarcomeres during eccentric exercise, fewer fast-twitch muscle fibers, and greater and perhaps more varied habitual physical activity patterns.
Publisher: American Physiological Society
Date: 10-2004
DOI: 10.1152/JAPPLPHYSIOL.00182.2004
Abstract: The purpose of this study was to assess the interactive effects of habitual physical activity (total and vigorous intensity) and calcium intake on bone mineral content (BMC) in prepubertal boys and girls. Seventy-six children, aged 8–11 yr, wore accelerometers for up to 7 days to assess activity. Calcium intake was estimated by a 4-day weighted food diary. BMC and areal density (bone mineral density) were measured at the total body, proximal femur, and femoral neck by using dual-energy X-ray absorptiometry. Moderated regression analyses were used to assess the contributions of physical activity (total and vigorous) and calcium intake to BMC, residualized for bone area and body mass. Interactive effects of vigorous activity (≥6 metabolic equivalents) and calcium intake were found at the total body in boys ( b = 2.90 × 10 −3 ) and in girls ( b = 6.58 × 10 −3 ) and at the proximal femur ( b = 9.87 × 10 −5 ) and femoral neck ( b = 2.29 × 10 −5 where b is the regression coefficient from final equation) in boys only residualized BMC was high only if both vigorous activity and calcium intake were high. There were no interactive effects of total activity and calcium intake. This study provides evidence for synergistic action of habitual vigorous activity and calcium intake on bone mass in children. Recommendations for optimizing bone mass should reflect this synergism.
Publisher: The University of Jordan
Date: 06-2022
Abstract: Background: COVID-19 pandemic emerged in China, Wuhan in December, 2019. This pandemic has affected most domains of quality of life (QoL) for all in iduals. Objective: The aim of this study was to assess the quality of life among disabled persons and healthy-normal in iduals during COVID-19 pandemic to compare it with their QoL before COVID-19 pandemic, in Jordan. Methods: Six hundred and thirty nine able-bodied participants (33.8 ± 11.3 years) and 143 disabled in iduals (46.8 ± 16.4 years) completed the WHOQOL-BREF (a tool used to measure Quality of life) which is consisted of 24 items distributed in four domains (physical health, psychology, social relationships and environment) and 2 items on overall quality of life and general health. The survey was distributed to participants online through social media (WhatsApp, Facebook, emails) between 12th June and 18th July 2021. Results: Quality of life values were higher in able-bodied participants for physical health (65.5 ± 16.3 vs. 56.2 ± 19.8), social relationships 63.2 ± 19.7 vs. 55.3 ± 21.1) and environment (53.6 ± 16.6 vs. 49.8 ± 17.9) domains. The quality of life correlated positively with in iduals’ income for both groups and higher in all domains for physically active compared to non-physically active participants. Screen time significantly increased during COVID-19 for both groups. Conclusion: The authors recommended that more attention should be paid to all items of quality of life during COVID-19, particularly with regard to disabled persons, and to potential deleterious effects which may result from sedentary lifestyle behavior such as higher screen time usage during COVID-19.
Publisher: Elsevier BV
Date: 02-1995
Publisher: Elsevier BV
Date: 04-2008
DOI: 10.1016/J.YPMED.2007.11.004
Abstract: To characterize the pattern of activity in boys and girls across weekdays and weekend days. Physical activity was recorded every 2 s by uniaxial accelerometry in 84 children, aged 9-11 years, for up to four weekdays and two weekend days. Activity bouts (>or= 4 s and >or= 5 min) greater than light (>or= LIGHT), moderate (>or= MOD) and vigorous (>or= VIG) intensity were recorded. The study took place in the South-West of England in 2007. The mean duration of activity bouts decreased as intensity increased from 11.0+/-1.3 s for >or= LIGHT activity to 6.1+/-1.0 s for >or= VIG activity. The frequency, duration and intensity of bouts were greater in boys than girls, and the frequency and duration of bouts were greater on weekdays than weekend days. Girls accumulated more activity sporadically than boys, whereas boys accumulated more activity in >or= 5-min bouts. Sex differences and weekday/weekend differences in activity were largely due to the intensity of the most frequent bouts of activity and frequency of the most intense bouts. Information regarding the pattern of children's habitual activity can be used to inform activity interventions and assess the aspects of the activity pattern that are related to health.
Publisher: Elsevier BV
Date: 08-1998
Publisher: Wiley
Date: 09-06-2009
DOI: 10.1111/J.1469-8986.2009.00826.X
Abstract: This study assessed the validity of the Eston-Parfitt (E-P) curvilinear Ratings of Perceived Exertion (RPE) Scale and a novel marble quantity task to provide estimates of perceived exertion during cycle ergometry. Fifteen children aged 7-8 years performed a discontinuous incremental graded-exercise test, and reported exertional ratings at the end of each minute. Significant increases in physiological and perceptual data were observed with increasing work rate. The relationship between work rate and marbles was curvilinear (mean R(2)=.94), supporting the theoretical justification for the E-P Scale. Strong linear (R(2)=.93) and curvilinear (R(2)=.94) relationships between RPE from the E-P Scale and work rate confirmed the robustness of the E-P Scale. Valid exertional ratings may be obtained using the E-P Scale with young children. The novel marble quantity task offers an alternative method of deriving perceived exertion responses in children.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2010
Publisher: Wiley
Date: 30-09-2023
DOI: 10.1111/RESP.14382
Abstract: Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub‐groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007–2019) were used to identify spirometry parameter z‐score trajectories, using group‐based multi‐trajectory modelling (GBMTM). Analysis of variance and chi‐square statistics were used to assess trajectory group differences in baseline self‐reported demographic, lifestyle and occupational characteristics. In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z‐score (FEV 1 z), Forced Vital Capacity z‐score (FVCz) and the ratio of FEV 1 and FVC z‐score (FEV 1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. GBMTM defined distinct, plausible spirometry trajectory sub‐groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self‐reported smoking history or occupational factors.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2009
DOI: 10.1007/S00421-009-1094-6
Abstract: This study examined the effect of exercise-induced muscle damage (EIMD) on ventilatory and perceived exertion responses to cycle exercise. Ten healthy, physically active men cycled for 6 min at moderate intensity and to exhaustion at severe intensity before and 48 h after eccentric exercise (100 squats with a load corresponding to 70% of body mass). Changes in ventilation and ratings of perceived exertion (RPE) were calculated for each in idual and expressed against time (moderate and severe exercise) and as a percentage of time to exhaustion (severe exercise). Ventilation increased during moderate exercise at 48 h V(E) 34.5 +/- 5.0 to 36.3 +/- 3.8 l min(-1), P < 0.05) but increases in RPE were not significant. During severe exercise at 48 h, time to exhaustion (TTE) was reduced and V(E) (87.1 +/- 14.1 to 93.8 +/- 11.7 l min(-1)) and RPE (15.5 +/- 1.3 to 16.1 +/- 1.4) were elevated (P < 0.05). When expressed as a percentage of TTE, the differences in ventilation and RPE values disappeared. Findings indicate that the augmented ventilatory response to cycle exercise following EIMD may be an important cue in informing effort perception during high-intensity exercise but not during moderate-intensity exercise.
Publisher: Springer Science and Business Media LLC
Date: 28-04-2007
DOI: 10.1007/S00421-007-0448-1
Abstract: Neuromuscular performance capabilities, including those measured by evoked responses, may be adversely affected by fatigue however, the capability of the neuromuscular system to initiate muscle force rapidly under these circumstances is yet to be established. Sex-differences in the acute responses of neuromuscular performance to exercise stress may be linked to evidence that females are much more vulnerable to anterior cruciate ligament injury than males. Optimal functioning of the knee flexors is paramount to the dynamic stabilisation of the knee joint, therefore the aim of this investigation was to examine the effects of acute maximal intensity fatiguing exercise on the voluntary and magnetically-evoked electromechanical delay in the knee flexors of males and females. Knee flexor volitional and magnetically-evoked neuromuscular performance was assessed in seven male and nine females prior to and immediately after: (1) an intervention condition comprising a fatigue trial of 30-s maximal static exercise of the knee flexors, (2) a control condition consisting of no exercise. The results showed that the fatigue intervention was associated with a substantive reduction in volitional peak force that was greater in males compared to females (15.0, 10.2%, respectively, P < 0.01) and impairment to volitional electromechanical delay in females exclusively (19.3%, P < 0.05). Similar improvements in magnetically-evoked electromechanical delay in males and females following fatigue (21%, P < 0.001), however, may suggest a vital facilitatory mechanism to overcome the effects of impaired voluntary capabilities, and a faster neuromuscular response that can be deployed during critical times to protect the joint system.
Publisher: BMJ
Date: 18-08-2018
DOI: 10.1136/BJSPORTS-2018-099153
Abstract: Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation. Systematic review with meta-analysis. MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science. Studies assessing change in CRF (reported as peak oxygen uptake V̇O 2peak ) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O 2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction % were excluded. 128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O 2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absolute V̇O 2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF. Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O 2peak . Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O 2peak , differences in pooled effects between intensities could not be considered clinically meaningful. Prospero CRD42016035638.
Publisher: Georg Thieme Verlag KG
Date: 17-12-2009
Abstract: The study aimed to assess the reproducibility of power output during a 4 min (TT4) and a 20 min (TT20) time-trial and the relationship with performance markers obtained during a laboratory graded exercise test (GXT). Ventilatory and lactate thresholds during a GXT were measured in competitive male cyclists (n=15 (.)VO (2max) 67+/-5 ml x min (-1) x kg (-1) P (max) 440+/-38W). Two 4 min and 20 min time-trials were performed on flat roads. Power output was measured using a mobile power-meter (SRM). Strong intraclass-correlations for TT4 ( R=0.98 95% CL: 0.92-0.99) and TT20 ( R=0.98 95% CL: 0.95-0.99) were observed. TT4 showed a bias+/-random error of - 0.8+/-23W or - 0.2+/-5.5%. During TT20 the bias+/-random error was - 1.8+/-14W or 0.6+/-4.4%. Both time-trials were strongly correlated with performance measures from the GXT (p<0.001). Significant differences were observed between power output during TT4 and GXT measures (p<0.001). No significant differences were found between TT20 and power output at the second lactate-turn-point (LTP2) (p=0.98) and respiratory compensation point (RCP) (p=0.97). In conclusion, TT4 and TT20 mean power outputs are reliable predictors of aerobic endurance. TT20 was in agreement with power output at RCP and LTP2.
Publisher: Informa UK Limited
Date: 1999
Abstract: Cryotherapy is an effective treatment for acute sports injury to soft tissue, although the effect of cryotherapy on exercise-induced muscle damage is unclear. The aim of this study was to assess the effects of cold water immersion on the symptoms of exercise-induced muscle damage following strenuous eccentric exercise. After performing a bout of damage-inducing eccentric exercise (eight sets of five maximal reciprocal contractions at 0.58 rad x s(-1)) of the elbow flexors on an isokinetic dynamometer, 15 females aged 22.0+/-2.0 years (mean +/- s) were allocated to a control group (no treatment, n = 7) or a cryotherapy group (n = 8). Subjects in the cryotherapy group immersed their exercised arm in cold water (15 degrees C) for 15 min immediately after eccentric exercise and then every 12 h for 15 min for a total of seven sessions. Muscle tenderness, plasma creatine kinase activity, relaxed elbow angle, isometric strength and swelling (upper arm circumference) were measured immediately before and for 3 days after eccentric exercise. Analysis of variance revealed significant (P < 0.05) main effects for time for all variables, with increases in muscle tenderness, creatine kinase activity and upper arm circumference, and decreases in isometric strength and relaxed elbow angle. There were significant interactions (P<0.05) of group x time for relaxed elbow angle and creatine kinase activity. Relaxed elbow angle was greater and creatine kinase activity lower for the cryotherapy group than the controls on days 2 and 3 following the eccentric exercise. We conclude that although cold water immersion may reduce muscle stiffness and the amount of post-exercise damage after strenuous eccentric activity, there appears to be no effect on the perception of tenderness and strength loss, which is characteristic after this form of activity.
Publisher: Springer Science and Business Media LLC
Date: 11-1992
DOI: 10.1007/BF00243513
Publisher: Springer Science and Business Media LLC
Date: 04-1989
DOI: 10.1007/BF00846687
Publisher: Informa UK Limited
Date: 11-1988
DOI: 10.1080/00140138808966819
Abstract: While infantile myofibromatosis is the most common mesenchymal tumour of infancy, only around 300 cases have been reported. The authors report a 33-year-old para 1 with an uncomplicated, dichorionic diamniotic twin pregnancy who was diagnosed with an intrauterine death of one twin at 36+5 weeks gestation. At caesarean section, a macerated male stillborn weighing 2.72 kg was delivered. Postmortem examination revealed a pedunculated lesion attached to the left shoulder and underlying muscle consistent with a congenital myofibroma. The cause of death was postulated to be haemorrhage from the tumour surface causing fetal anaemia.
Publisher: SAGE Publications
Date: 09-10-2018
Abstract: To establish the discriminant validity of the athletic ability assessment in elite Australian rules football. Secondarily, to examine the association between athletic ability assessment and maximum running velocity extracted from elite Australian rules football game-play. To establish the discriminant validity of the athletic ability assessment, 43 Australian Football League players from one club were split into two groups based upon playing status ‘starters’ ( n = 17 selected in 50% of the first 10 games of the Australian Football League season), ‘non-starters’ ( n = 26 not selected in 50% of the first 10 games of the Australian Football League season). Each group performed a modified version of the athletic ability assessment consisting of five foundational athletic movements. An independent-s led t-test modelled the effect of player group (starters non-starters) on the total score and for each in idual exercise. Pearson product moment correlation was also conducted to establish the association between maximum running velocity and athletic ability assessment. The starters attained a significantly greater total mean score on the athletic ability assessment ( d = 1.04, p 0.05), overhead squat ( d = 0.96, p 0.05), double lunge left ( d = 0.64, p 0.05), single leg Romanian deadlift left ( d = 1.19, p 0.05) and right single leg Romanian dead lift ( d = 0.79, p 0.05) relative to the non-starters. Also noted were moderate, positive correlations between maximum running velocity and athletic ability assessment ( r = 0.31–0.46 p 0.05). The results support the use of the athletic ability assessment to measure movement competency in elite Australian rules football. Accordingly, physical development coaches may consider its integration in high-performance training programs.
Publisher: Informa UK Limited
Date: 20-09-2013
DOI: 10.1080/17461391.2013.832804
Abstract: A maximal, perceptually-regulated exercise test (PRETmax) whereby participants control the intensity according to preset ratings of perceived exertion (RPE) may induce more positive affective responses than a conventional 'experimenter controlled' incremental r test (Ir ). The authors aimed to assess (1) if a PRETmax could be used to measure VO(2max) and (2) if affective responses differed between the PRETmax and Ir . Sixteen participants (age 20.5, s=1.2 y) completed a PRETmax which required them to adjust the resistance on a recumbent cycle ergometer to correspond to prescribed RPEs of 9, 11, 13, 15, 17 and 20 and an Ir . Both tests ended with volitional exhaustion. Affect was recorded every minute throughout exercise using the Feeling Scale (FS). There was no difference (P>0.05) between VO(2max) measured by PRETmax (43.5, s=4.1 ml kg(-1) min(-1)) and Ir (44.3, s=4.9 ml kg(-1) min(-1)). Participants reported feeling significantly less negative (P<0.001) throughout the PRETmax compared to Ir (average mean difference FS = 1.4, s=0.1). The PRETmax has application in situations where the direct measurement of VO(2max) is required and the affective responses of the in idual are considered to be important.
Publisher: Informa UK Limited
Date: 20-05-2013
DOI: 10.1080/17461391.2013.799716
Abstract: The effects of flexibility conditioning on neuromuscular and sensorimotor performance were assessed near to full knee extension (25°). Eighteen males who were randomly assigned into two groups underwent eight weeks (three-times per week) of flexibility conditioning (hip region/knee flexor musculature dominant limb) involving either proprioceptive neuromuscular facilitation (PNF) (n=9) or passive stretching (PASS) (n=9). Both modes of flexibility conditioning are popular within contemporary exercise and clinical settings and have demonstrated efficacy in improving range of motion. The contralateral limb and a prior 'no exercise' condition were used as controls. The PNF and PASS modes of conditioning improved passive hip flexibility to a similar extent (mean 19.3% vs. baseline, intervention limb, p<0.01) but did not alter knee flexor strength (overall mean 309.6±81 N) or sensorimotor performance (force and positional errors: 2.3±8.2% and 0.48±7.1%). Voluntary and magnetically evoked electromechanical delays (EMDV and EMDE, respectively) were increased but to a greater extent following PASS compared to PNF (PASS: 10.8% and 16.9% lengthening of EMDV and EMDE, respectively vs. PNF: 3.2% and 6.2%, p<0.01).The attenuated change to electromechanical delay (EMD) performance during PNF conditioning suggests a preserved capability for rapid muscle activation, which is important in the maintenance of dynamic joint stability. That PNF was also equally efficacious in flexibility conditioning would suggest that this mode of flexibility training should be used over passive to help preserve dynamic joint stability capabilities at this extended and vulnerable joint position.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2014
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2012
Publisher: Springer Science and Business Media LLC
Date: 11-05-2005
DOI: 10.1007/S00421-005-1357-9
Abstract: Exercise-induced muscle damage (EIMD) is a common occurrence following activities with a high eccentric component. Alterations to the torque-velocity relationship following EIMD would appear to have serious implications for athletic performance, particularly as they relate to impairment of maximal intensity exercise. However, this has been studied infrequently. The purpose of this study was to assess the effects of EIMD on maximal intermittent sprint performance. Ten male participants (age 22.4 +/- 3.2 years, height 178.6 +/- 5.2 cm, mass 80.6 +/- 10.7 kg) performed 10 x 6 s cycle ergometer sprints, interspersed with 24 s recovery against a load corresponding to 0.10 kp/kg and 10 x 10 m sprints from a standing start, each with 12 s active (walking) recovery. All variables were measured immediately before and at 30 min, 24, 48 and 72 h following a plyometric exercise protocol comprising of 10 x 10 maximal counter movement jumps. Repeated measures ANOVA showed significant changes over time (all P<0.05) for perceived soreness, plasma creatine kinase activity (CK), peak power output (PPO), sprint time and rate of fatigue. Soreness was significantly higher (P<0.01) than baseline values at all time intervals (3.1, 4.9, 5.5 and 3.2 at 30 min, 24, 48 and 72 h, respectively). CK was significantly elevated (P<0.05) at 24 h (239 IU/l) and 48 h (245 IU/l) compared to baseline (151 IU/l). PPO was significantly lower (P<0.05) than baseline (1,054 W) at all time intervals (888, 946, 852 and 895 W, at 30 min, 24, 48 and 72 h, respectively). The rate of fatigue over the ten cycling sprints was reduced compared to baseline, with the greatest reduction of 48% occurring at 48 h (P<0.01). This was largely attributed to the lower PPO in the initial repetitions, resulting in a lower starting point for the rate of fatigue. Values returned to normal at 72 h. Sprint times over 10 m were higher (P<0.05) at 30 min, 24 h and 48 h compared to baseline (1.96 s) with values corresponding to 2.01, 2.02 and 2.01 at 30 min, 24 h and 48 h, respectively. Values returned to baseline by 72 h. The results provide further evidence that, following a plyometric, muscle-damaging exercise protocol, the ability of the muscle to generate power is reduced for at least 3 days. This is also manifested by a small, but statistically significant reduction in very short-term (approximately 2 s) intermittent sprint running performance. These findings have implications for appropriate training strategies in multiple sprint sports.
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Elsevier BV
Date: 06-2013
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2019
DOI: 10.1249/MSS.0000000000001845
Abstract: This study investigated the effect of β-blockade on physiological and perceived exertion (RPE) responses during incremental treadmill exercise. Sixteen healthy participants ( n = 8 men age, 25.3 ± 4.6 yr) performed a maximal treadmill exercise test after ingestion of 100 mg metoprolol or placebo, with a double-blind, randomized, and counterbalanced design. Heart rate (HR), ventilatory, and gas exchange variables were measured continuously, and participants reported RPE at the end of each minute. Physiological and RPE responses during each condition were compared at the ventilatory threshold (VT), respiratory compensation point, and at maximal exercise using repeated-measures ANOVA. Linear regression modeled relationships between perceived exertion and physiological variables. The HR and V˙O 2 at the VT, respiratory compensation point, and maximal exercise were all significantly lower after β-blockade ( P 0.05). However, when standardized to within condition peak values, differences were no longer significant. The RPE associated with VT was higher after β-blockade (12.9 ± 1.0 vs 12.3 ± 1.2, P 0.05) but lower at maximal exercise (19.1 ± 0.6 vs 19.4 ± 0.5, P 0.05). Increases in RPE relative to HR were greater after β-blockade and remained significant when expressed relative to peak HR. There was no difference in the growth of the relationship between RPE and V˙O 2 across conditions, although the origin of the relationship was higher with β-blockade. Although β-blockade resulted in a significant reduction in exercising HR and V˙O 2 , the RPE for a given relative intensity remained unchanged. The relationship between RPE and V˙O 2 was not affected by β-blockade. The results provide evidence that RPE is a useful and reliable measure for exercise testing and prescription in patients prescribed β-blockade therapy.
Publisher: Routledge
Date: 21-01-2022
Publisher: Springer Science and Business Media LLC
Date: 18-11-2021
Publisher: Springer Science and Business Media LLC
Date: 12-02-2014
DOI: 10.1007/S40279-013-0139-5
Abstract: Maximal or peak oxygen uptake (V˙O2 max and V˙O2 peak , respectively) are commonly measured during graded exercise tests (GXTs) to assess cardiorespiratory fitness (CRF), to prescribe exercise intensity and/or to evaluate the effects of training. However, direct measurement of CRF requires a GXT to volitional exhaustion, which may not always be well accepted by athletes or which should be avoided in some clinical populations. Consequently, numerous studies have proposed various sub-maximal exercise tests to predict V˙O2 max or V˙O2 peak . Because of the strong link between ratings of perceived exertion (RPE) and oxygen uptake (V˙O2), it has been proposed that the in idual relationship between RPE and V˙O2 (RPE:V˙O2) can be used to predict V˙O2 max (or V˙O2 peak) from data measured during submaximal exercise tests. To predict V˙O2 max or V˙O2 peak from these linear regressions, two procedures may be identified: an estimation procedure or a production procedure. The estimation procedure is a passive process in which the in idual is typically asked to rate how hard an exercise bout feels according to the RPE scale during each stage of a submaximal GXT. The production procedure is an active process in which the in idual is asked to self-regulate and maintain an exercise intensity corresponding to a prescribed RPE. This procedure is referred to as a perceptually regulated exercise test (PRET). Recently, prediction of V˙O2max or V˙O2 peak from RPE:V˙O2 measured during both GXT and PRET has received growing interest. A number of studies have tested the validity, reliability and sensitivity of predicted V˙O2 max or V˙O2 peak from RPE:V˙O2 extrapolated to the theoretical V˙O2 max at RPE20 (or RPE19). This review summarizes studies that have used this predictive method during submaximal estimation or production procedures in various populations (i.e., sedentary in iduals, athletes and pathological populations). The accuracy of the methods is discussed according to the RPE:V˙O2 range used to plot the linear regression (e.g., RPE9–13 versus RPE9–15 versus RPE9–17 during PRET), as well as the perceptual endpoint used for the extrapolation (i.e., RPE19 and RPE20). The V˙O2 max or V˙O2 peak predictions from RPE:V˙O2 are also compared with heart rate-related predictive methods. This review suggests that V˙O2 max (or V˙O2 peak ) may be predicted from RPE:V˙O2 extrapolated to the theoretical V˙O2 max (or V˙O2 peak) at RPE20 (or RPE19). However, it is generally preferable to (1) extrapolate RPE:V ˙ O 2 to RPE19 (rather than RPE20) (2) use wider RPE ranges (e.g. RPE ≤ 17 or RPE9–17) in order to increase the accuracy of the predictions and (3) use RPE ≤ 15 or RPE9–15 in order to reduce the risk of cardiovascular complications in clinical populations.
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.JSAMS.2014.03.006
Abstract: This systematic review aimed to (i) report the accuracy of submaximal exercise-based predictive equations that incorporate oxygen uptake (measured via open circuit spirometry) to predict maximal oxygen uptake (VO₂max) and (ii) provide a critical reflection of the data to inform health professionals and researchers when selecting a prediction equation. Systematic review. A systematic search of MEDLINE, EMBASE (via OvidSP), CINAHL, SPORTDiscus (via EBSCO Host) and Scopus databases was undertaken in February 2013. Studies were required to report data on healthy participants aged 18-65y. Following tabulation of extracted data, a narrative synthesis was conducted. From a total of 7597 articles screened, 19 studies were included, from which a total of 43 prediction equations were extracted. No significant difference was reported between the measured and predicted VO₂max in 28 equations. Pearson's correlation coefficient between the predicted and measured VO₂max ranged from r=0.92 to r=0.57. The variables most commonly used in predictive equations were heart rate (n=19) and rating of perceived exertion (n=24). Overall, submaximal exercise-based equations using open circuit spirometry to predict VO₂max are moderately to highly accurate. The heart rate and rating of perceived exertion methods of predicting VO₂max were of similar accuracy. Important factors to consider when selecting a predictive equation include: the level of exertion required participant medical conditions or medications the validation population mode of ergometry time and resources available for familiarisation trials and the level of bias of the study from which equations are derived.
Publisher: MDPI AG
Date: 19-11-2022
Abstract: The aim of this study is to determine the magnitude of maximal fat oxidation (MFO) during incremental upper and lower body exercise. Thirteen non-specifically trained male participants (19.3 ± 0.5 y, 78.1 ± 9.1 kg body mass) volunteered for this repeated-measures study, which had received university ethics committee approval. Participants undertook two incremental arm crank (ACE) and cycle ergometry (CE) exercise tests to volitional exhaustion. The first test for each mode served as habituation. The second test was an in idualised protocol, beginning at 40% of the peak power output (POpeak) achieved in the first test, with increases of 10% POpeak until volitional exhaustion. Expired gases were recorded at the end of each incremental stage, from which fat and carbohydrate oxidation rates were calculated. MFO was taken as the greatest fat oxidation value during incremental exercise and expressed relative to peak oxygen uptake (%V˙O2peak). MFO was lower during ACE (0.44 ± 0.24 g·min−1) than CE (0.77 ± 0.31 g·min−1 respectively, p 0.01) and occurred at a lower exercise intensity (53 ± 21 vs. 67 ± 18%V˙O2peak respectively, p 0.01). Inter-participant variability for MFO was greatest during ACE. These results suggest that weight loss programs involving the upper body should occur at lower exercise intensities than for the lower body.
Publisher: Springer Science and Business Media LLC
Date: 26-01-2012
DOI: 10.1007/S00421-012-2326-8
Abstract: The validity of predicting peak oxygen uptake ([Formula: see text]) in sedentary participants from a perceptually regulated exercise test (PRET) is limited to two cycle ergometry studies. We assessed the validity of a treadmill-based PRET. Active (n = 49 40.7 ± 13.8 years) and sedentary (n = 26 33.4 ± 13.2 y) participants completed two PRETS (PRET 1 and PRET2), requiring a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13 and 15. Extrapolation of RPE: [Formula: see text] data to RPE 19 and 20 from the RPE 9-13 and 9-15 ranges were used to estimate [Formula: see text], and compared to [Formula: see text] from a graded exercise test (GXT). The [Formula: see text] :heart rate (HR) data (≥RPE 15) from the GXT were also extrapolated to age-predicted maximal HR (HRmax(pred)) to provide further estimation of [Formula: see text]. ANOVA revealed no significant differences between [Formula: see text] predictions from the RPE 9-15 range for PRET 1 and PRET 2 when extrapolated to RPE 19 in both active (54.3 ± 7.4 52.9 ± 8.1 ml kg(-1) min(-1)) and sedentary participants (34.1 ± 10.2 34.2 ± 9.6 ml kg(-1) min(-1)) and no difference between the HRmax(pred) method and measured [Formula: see text] from the GXT for active (53.3 ± 10.0 53.9 ± 7.5 ml kg(-1) min(-1), respectively) and sedentary participants (33.6 ± 8.4, 34.4 ± 7.0 ml kg(-1) min(-1), respectively). A single treadmill-based PRET using RPE 9-15 range extrapolated to RPE 19 is a valid means of predicting [Formula: see text] in young and middle to older-aged in iduals of varying activity and fitness levels.
Publisher: Springer Science and Business Media LLC
Date: 2004
DOI: 10.2165/00007256-200434010-00005
Abstract: Exercise-induced muscle damage is a well documented phenomenon particularly resulting from eccentric exercise. When eccentric exercise is unaccustomed or is performed with an increased intensity or duration, the symptoms associated with muscle damage are a common outcome and are particularly associated with participation in athletic activity. Muscle damage results in an immediate and prolonged reduction in muscle function, most notably a reduction in force-generating capacity, which has been quantified in human studies through isometric and dynamic isokinetic testing modalities. Investigations of the torque-angular velocity relationship have failed to reveal a consistent pattern of change, with inconsistent reports of functional change being dependent on the muscle action and/or angular velocity of movement. The consequences of damage on dynamic, multi-joint, sport-specific movements would appear more pertinent with regard to athletic performance, but this aspect of muscle function has been studied less often. Reductions in the ability to generate power output during single-joint movements as well as during cycling and vertical jump movements have been documented. In addition, muscle damage has been observed to increase the physiological demand of endurance exercise and to increase thermal strain during exercise in the heat. The aims of this review are to summarise the functional decrements associated with exercise-induced muscle damage, relate these decrements to theoretical views regarding underlying mechanisms (i.e. sarcomere disruption, impaired excitation-contraction coupling, preferential fibre type damage, and impaired muscle metabolism), and finally to discuss the potential impact of muscle damage on athletic performance.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Informa UK Limited
Date: 1999
DOI: 10.1179/MHT.1999.002
Publisher: BMJ
Date: 21-10-2005
Abstract: Objectives: To determine if the changes in specific skinfold sites induced by intense athletic conditioning over a three year period were associated with changes in running performance in high level athletes. Methods: Thirty seven top class runners (eight male and five female sprint trained, 16 male and eight female endurance trained) volunteered to participate in the study. The athletes were ided into class A (n = 18) and class B (n = 17), with class A having the best performance. Biceps, triceps, subscapular, pectoral, iliac crest, abdominal, front thigh, and medial calf skinfold thickness and the best running performance were recorded at the beginning and after one, two, and three years of training. A one way analysis of variance and a linear regression analysis were conducted to determine changes and association between performance and skinfold thicknesses. Analyses were controlled for sex, sprint event or endurance event, and class. Results: Training resulted in a significant increase in performance and decreases in sum of six skinfolds, abdominal, front thigh, and medial calf skinfolds, and the ratio of extremity to trunk skinfolds (E/T, ∑triceps, front thigh, medial calf/∑subscapular, iliac crest, abdominal). There were no significant differences in body weight. Except for the abdominal skinfold, there was no significant difference in trunk skinfolds. Significant differences in these changes were observed by sex for E/T, which decreased and increased in male and female runners respectively, and by class. Class B runners significantly improved performance, with decreased skinfold thicknesses in the lower limb. There were no significant changes in performance or skinfold thicknesses in class A runners. Improvements in performance were consistently associated with a decrease in the lower limb skinfolds. Conclusions: On the basis of these findings, anthropometric assessment of top class athletes should include an evaluation of all skinfolds. The loss of body fat appears to be specific to the muscular groups used during training. The lower limb skinfolds may be particularly useful predictors of running performance.
Publisher: Springer Science and Business Media LLC
Date: 1984
DOI: 10.2165/00007256-198401060-00003
Abstract: The study of fluctuations in athletic performance attributable to the menstrual cycle has been an area of considerable interest and controversy for well over half a century. Studies have included simple observations of performance in athletic events, and have also documented specific physical, psychological and physiological changes as they relate to varying hormonal levels of the menstrual cycle. Advantages and disadvantages to human performance have been attributed to various phases of the cycle. Many investigators have documented evidence to suggest that the premenstrual phase is often associated with decreased performance. Others have noted that there are specific physiological changes, inherent in athletic performance, occurring in the follicular and luteal phases of the menstrual cycle. However, it is evident that there is conflict within the literature. This review considers the evidence for the cyclic effects of the regular or normal menstrual cycle on performance. It examines surveyed evidence of the effects of the regular menstrual cycle on athletic performance, effects on psychological and perceptual factors, maximum oxygen uptake, endurance and time to fatigue, temperature, sweating, bodyweight, respiratory drive, blood lactate, carbohydrate and lipid metabolism, and cardiovascular parameters. It is concluded that there is considerable variation in the findings of the literature and that any reported variations in performance may well be greatly influenced by intersubject variability, the nature of the exercise, and the nutritional status of the athlete, as well as minor changes that could be attributable to the menstrual cycle.
Publisher: Informa UK Limited
Date: 24-01-2022
DOI: 10.1080/17461391.2020.1867240
Abstract: The aim of this study was to analyse age-related performance progression and peak-performance age (PPA) in elite track and field athletes and to use a model to predict peak performance. Best performances of world-class athletes from ages 14 to 15 y up to and including the last Olympic year (
Publisher: Informa UK Limited
Date: 2012
DOI: 10.1080/02640414.2011.627370
Abstract: The effects of serial episodes of fatigue and recovery on volitional and magnetically evoked neuromuscular performance of the knee flexors were assessed in 20 female soccer players during: (i) an intervention comprising 4 × 35 s maximal static exercise, and (ii) a control condition. Volitional peak force was impaired progressively (-16% vs. baseline: 235.3 ± 54.7 to 198.1 ± 38.5 N) by the fatiguing exercise and recovered to within -97% of baseline values following 6 min of rest. Evoked peak twitch force was diminished subsequent to the fourth episode of exercise (23.3%: 21.4 ± 13.8 vs. 16.4 ± 14.6 N) and remained impaired at this level throughout the recovery. Impairment of volitional electromechanical delay performance following the first episode of exercise (25.5%: 55.3 ± 11.9 vs. 69.5 ± 24.5 ms) contrasted with concurrent improvement (10.0%: 24.5 ± 4.7 vs. 22.1 ± 5.0 ms) in evoked electromechanical delay (P < 0.05), and this increased disparity between evoked and volitional electromechanical delay remained during subsequent periods of intervention and recovery. The fatiguing exercise provoked substantial impairments to volitional strength and volitional electromechanical delay that showed differential patterns of recovery. However, improved evoked electromechanical delay performance might identify a dormant capability for optimal muscle responses during acute stressful exercise and an improved capacity to maintain dynamic joint stability during critical episodes of loading.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2023
Publisher: Springer Science and Business Media LLC
Date: 06-1991
DOI: 10.1007/BF00664707
Publisher: Wiley
Date: 12-1998
DOI: 10.1002/(SICI)1521-4176(199812)49:12<855::AID-MACO855>3.0.CO;2-5
Publisher: Springer Science and Business Media LLC
Date: 18-10-2014
DOI: 10.1007/S00421-014-3023-6
Abstract: We assessed the validity of predicting peak oxygen uptake ([Formula: see text]O2 peak) from the relationship between oxygen uptake ([Formula: see text]O2) and overall ratings of perceived exertion (RPE) obtained during the initial stages of a cardiopulmonary exercise test (CPET). Fifteen healthy participants and 18 patients with chronic obstructive pulmonary disease (COPD) performed a maximal CPET, during which [Formula: see text]O2 and RPE were measured until RPE15. In idual regressions between [Formula: see text]O2 and RPE ≤ 15 were extrapolated to RPE19 to predict [Formula: see text]O2 peak. Mean actual and predicted [Formula: see text]O2 peak were not significantly different in healthy women (18.9 ± 4.1 vs. 20.4 ± 4.5 mL kg(-1) min(-1), respectively) and men (28.9 ± 7.8 vs. 29.7 ± 8.5 mL kg(-1) min(-1), respectively), or in women (15.2 ± 4.7 vs. 15.8 ± 5.0 mL kg(-1) min(-1), respectively) and men (16.2 ± 4.4 vs. 17.4 ± 5.4 mL kg(-1) min(-1), respectively) with COPD (P = 0.067). Moreover, actual and predicted [Formula: see text]O2 peak were highly correlated in healthy participants and COPD patients (r ≥ 0.89 P < 0.001). The bias and 95 % limits of agreement were -1.0 ± 4.0 and -1.0 ± 4.6 mL kg(-1) min(-1) for healthy and COPD participants, respectively. [Formula: see text]O2 peak can be predicted with acceptable accuracy in healthy participants and patients with COPD from the in idual relationship between [Formula: see text]O2 and RPE ≤ 15.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.APMR.2015.09.023
Abstract: To evaluate and discuss the accuracy of submaximal exercise-based equations to predict maximum oxygen uptake (V˙o2max), validated using direct gas analysis, in older apparently healthy adults. Studies were identified by searching 5 electronic databases and manually scanning reference lists of included articles from the respective inception of each database through April 2015. Studies were included if they used at least 1 submaximal exercise-based variable in the prediction, the actual V˙o2max was directly measured using a gas analysis device, and if participants were apparently healthy older adults (mean age ≥65y). Eligible studies were required to report at least 1 validity statistic (eg, Pearson product-moment correlation [r]) and either a predicted and measured V˙o2max value or a directional significant difference between the measured and predicted V˙o2max values. No limits were placed on year of publication, but only full-text, published articles in the English language were included. Nine articles and 13 equations were retained from the systematic search strategy. If the same prediction equation was used across multiple trials, data from the most accurate trial were reported. Submaximal equations predicted directly measured V˙o2max with a moderate to strong correlation strength (r range, 0.4-0.9). Predicted V˙o2max significantly differed from directly measured in 2 of the 13 equations. The preferred mode of ergometry was walking or running (7 equations) a stepping protocol was the most accurate (R(2)=0.9, not significant between predicted and measured V˙o2max). Factors to consider when choosing a submaximal exercise-based equation are the accuracy of the equation, the population tested, the mode of ergometry, the equipment availability, and the time needed to conduct familiarization sessions.
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.APMR.2009.10.019
Abstract: To investigate the strength of the relationship between ratings of perceived exertion (RPE) and oxygen uptake (Vo(2)), heart rate, ventilation (Ve) and power output (PO) during an arm-crank r ed exercise test to volitional exhaustion in men and women who differed in physical status. Each participant completed an arm-crank r exercise test to volitional exhaustion. PO was increased by 15 W.min(-1) and 6 W.min(-1) for men and women able-bodied participants, respectively for the poliomyelitis participants, 9 W.min(-1) and 6 W.min(-1) increments were used for men and women, respectively. Laboratory facilities at a university. Able-bodied participants (n=16 9 men, 7 women) and participants with poliomyelitis (n=15, 8 men, 7 women) volunteered for the study. Strength of the relationship (R(2) values) between RPE and Vo(2), heart rate, Ve and PO. There were significantly higher values for maximum Vo(2) and maximum PO for able-bodied men compared with their counterparts with poliomyelitis (P .05). Similar results were observed for the women who were able-bodied as well as for the women who had poliomyelitis (P>.05). The relationships between heart rate and RPE and Ve and RPE for able-bodied patients and patients with poliomyelitis were similar (R(2)>.87). The relationship between Vo(2) and RPE was stronger in the able-bodied participants compared wih the participants with poliomyelitis, regardless of sex (P .05). RPE is strongly related to physiologic markers of exercise intensity during arm exercise, irrespective of sex or participant's poliomyelitis status.
Publisher: Wiley
Date: 27-04-2016
DOI: 10.1111/CPF.12365
Abstract: The aim of this observational study was to compare head motion and prefrontal haemodynamics during exercise using three commercial cycling ergometers. Participants (n = 12) completed an incremental exercise test to exhaustion during upright, recumbent and semi-recumbent cycling. Head motion (using accelerometry), physiological data (oxygen uptake, end-tidal carbon dioxide [P
Publisher: The Electrochemical Society
Date: 06-1994
DOI: 10.1149/1.2054947
Publisher: Elsevier BV
Date: 2009
Publisher: Springer Science and Business Media LLC
Date: 09-03-2014
DOI: 10.1007/S00421-014-2850-9
Abstract: To assess the validity of predicting peak oxygen uptake (VO(2peak)) from differentiated ratings of perceived exertion (RPE) obtained during submaximal wheelchair propulsion. Three subgroups of elite male wheelchair athletes [nine tetraplegics (TETRA), nine paraplegics (PARA), eight athletes without spinal cord injury (NON-SCI)] performed an incremental speed exercise test followed by graded exercise to exhaustion (VO(2peak) test). Oxygen uptake (VO₂), heart rate (HR) and differentiated RPE (Central RPE(C), Peripheral RPE(P) and Overall RPE(O)) were obtained for each stage. The regression lines for the perceptual ranges 9-15 on the Borg 6-20 scale ratings were performed to predict VO(2peak). There were no significant within-group mean differences between measured VO(2peak) (mean 1.50 ± 0.39, 2.74 ± 0.48, 3.75 ± 0.33 L min(-1) for TETRA, PARA and NON-SCI, respectively) and predicted VO(2peak) determined using HR or differentiated RPEs for any group (P > 0.05). However, the coefficients of variation (CV %) between measured and predicted VO(2peak) using HR showed high variability for all groups (14.3, 15.9 and 9.7%, respectively). The typical error ranged from 0.14 to 0.68 L min(-1) and the CV % between measured and predicted VO(2peak) using differentiated RPE was ≤11.1% for TETRA, ≤7.5% for PARA and ≤20.2% for NON-SCI. Results suggest that differentiated RPE may be used cautiously for TETRA and PARA athletes when predicting VO(2peak) across the perceptual range of 9-15. However, predicting VO(2peak) is not recommended for the NON-SCI athletes due to the large CV %s (16.8, 20.2 and 18.0% RPE(C), RPE(P) and RPE(O), respectively).
Publisher: Elsevier BV
Date: 10-1996
Publisher: Informa UK Limited
Date: 2009
DOI: 10.1080/03014460902824220
Abstract: Components of activity that are more variable over time may be more susceptible to manipulation in activity interventions. The present study examined variability and consistency of components of children's activity across season. Sixty-four 9-11-year-old children wore an accelerometer for 6 days during winter and summer. Activity bouts (>or=4 s) greater than light (>or=LIGHT), moderate (>or=MOD) and vigorous (>or=VIG) intensity were recorded. Intra-in idual variability of the activity components across season was greater for bout frequency (CV: >or=LIGHT = 6.6-9.9%, >or=MOD = 10.7-16.1%, >or=VIG = 17.0-26.8%) than bout intensity or duration (CV: >or=LIGHT = 3.4-7.4%, >or=MOD = 3.6-7.8%, >or=VIG = 4.2-10.0%, p or=VIG bouts compared to the frequency of >or=LIGHT and >or=MOD bouts (p or=LIGHT and >or=MOD bouts (intra-class correlations (ICC) = 0.47-83, p or=VIG bouts in boys (ICC = 0.69-0.77, p or=VIG bouts in girls (ICC = 0.82, p<0.01). Bout frequency was the most variable component of activity across season. However, children tended to maintain their rank for bout frequency. It would be of interest to investigate whether bout frequency can be manipulated in an activity intervention.
Publisher: BMJ
Date: 04-2003
Abstract: Exercise induced muscle damage (EIMD) from strenuous unaccustomed eccentric exercise is well documented. So too is the observation that a prior bout of eccentric exercise reduces the severity of symptoms of EIMD. This has been attributed to an increase in sarcomeres in series. Recent studies have suggested that prior concentric training increases the susceptibility of muscle to EIMD following eccentric exercise. This has been attributed to a reduction of sarcomeres in series, which decreases muscle compliance and changes the length-tension relation of muscle contraction. To assess the effects of prior concentric training on the severity of EIMD. Four men and four women (mean (SD) age 21.1 (0.8) years) followed a four week concentric training programme. The elbow flexor musculature of the non-dominant arm was trained at 60% of one repetition maximum dynamic concentric strength performance, three times a week, increasing to 70% by week 3. After three days of rest, participants performed 50 maximal isokinetic eccentric contractions on both arms. All participants gave written informed consent before taking part in this study, which was approved by the school ethics committee. Strength, relaxed arm angle (RAA), arm circumference, and soreness on active extension and flexion were recorded immediately before eccentric exercise, one hour after, and at 24 hour intervals for three days. Data were analysed with fully repeated measures analyses of variance. Strength retention was significantly (p<0.01) greater in the control arm than the trained arm (84.0 (13.7)%, 90.4 (14.7)%, 95.2 (10.5)%, 103.5 (7.6)% v 75.5 (11.3)%, 77.6 (15.3)%, 80.1 (13.9)%, 80.9 (12.5)%) at one, 24, 48, and 72 hours respectively. Similarly, soreness was greater in the trained arm (0.7 (0.6), 3.1 (1.4), 3.0 (1.5), 1.9 (2.3)) than in the untrained arm (0 (0.2), 1.6 (1.3), 1.4 (0.6), 0.6 (0.4)) at one, 24, 48, and 72 hours respectively (p<0.05). Concentric training induced a significant reduction in RAA (165.2 (6.7) degrees v 157.3 (4.9) degrees ) before the eccentric exercise bout (p<0.01). This was further reduced and remained lower in the trained arm at all time points after the eccentric exercise (p<0.01). The arm circumference of the concentrically trained arm was significantly greater than baseline (p<0.05) at 72 hours (30.3 (2.9) v 29.8 (3.3) cm). These findings extend the understanding of the effects of prior concentric training in increasing the severity of EIMD to an upper limb exercise model. The inclusion of concentric conditioning in rehabilitation programmes tends to exacerbate the severity of EIMD in subsequent unaccustomed exercise. However, where concentric conditioning is indicated clinically, the net effect of conditioning outcome and EIMD may still confer enhanced strength performance and capability to dynamically stabilise a joint system.
Publisher: BMJ
Date: 08-2000
Abstract: (a) To assess the validity and reliability of producing and reproducing a given exercise intensity during cycle ergometry using a braille version of Borg's standard 6-20 rating of perceived exertion (RPE) scale, and (b) to determine whether the exercise responses of blind participants, at a given produced RPE, were similar to those reported in recognised guidelines for sighted subjects. Ten healthy registered blind volunteer participants (four women, six men mean (SD) age 23.2 (9.0) years) performed an initial graded exercise cycle test to determine maximal heart rate (HRMAx) and maximal oxygen uptake (VO2MAX). Three trials of three exercise bouts at RPEs 9, 11, and 13 were then performed in random order on three separate days of the same week, with expired air and heart rate measured continuously. Each exercise bout was followed by 10 minutes of rest. The validity of the scale as a means of producing different exercise intensities was assessed using a two factor (RPE x trial) repeated measures analysis of variance. Intertrial reliability was assessed using intraclass correlation coefficients (ICC) and the bias +/-95% limits of agreement (95%LoA) procedure. Participants reported no difficulty in using the braille RPE scale. When asked to produce exercise intensities equating to RPE 9, 11, and 13, they elicited mean %VO2MAX values of 47%, 53%, and 63% respectively. Analysis of variance showed no significant differences in either %HRMAx or %VO2MAX between trials at each of the three RPEs, but there was a significant difference (p<0.001) in both %HRMAx and %VO2MAX between the three RPE levels. All pairwise comparisons of the three different RPEs were significantly different (p<0.016). The ICC between the second and third trial for %HRMAx was significant (p <0.05) for all three RPEs. Similarly for %VO2MAX, the ICC was significant for RPE 9 and 11 but not 13. The 95%LoA decreased for both %HRMAx and %VO2MAX with each successive trial. Blind participants were successful in using a braille RPE scale to differentiate exercise intensity on a cycle ergometer. In every trial at RPE 13, all participants achieved %HRMAX and %VO2MAX levels, which fell within the recommendedrange for developing cardiorespiratory fitness. Using %HRMAx as a judge of intertrial reliability, the participants were able to repeat similar exercise intensities after two trials at each of the three RPEs (9, 11,13). The same was true for RPE 9 and 11, when %VO2MAX was used as a judge, but further trials were required to achieve similar reliability at RPE 13. A braille RPE scale can be used by healthy blind people during cycle ergometry, with similar effect to the visual analogue scale recommended for use in healthy sighted people.
Publisher: Springer Science and Business Media LLC
Date: 28-02-2017
Publisher: Cambridge University Press (CUP)
Date: 12-1997
DOI: 10.1079/BJN19970216
Publisher: Elsevier BV
Date: 12-2013
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2007
Publisher: Springer Science and Business Media LLC
Date: 08-1995
DOI: 10.1007/BF01046720
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2019
DOI: 10.1519/JSC.0000000000002175
Abstract: Rogers, DK, McKeown, I, Parfitt, G, Burgess, D, and Eston, RG. Inter- and intra-rater reliability of the athletic ability assessment in subelite Australian rules football players. J Strength Cond Res 33(1): 125–138, 2019—The aim of this study was to determine the inter- and intra-rater rater reliability of the Athletic Ability Assessment (AAA) in subelite Australian Rules football (ARF) players. Eighteen male ARF players completed the AAA movement assessment (overhead squat, double lunge [left and right], single-leg Romanian deadlift [left and right], chin-up and push-up), on 2 occasions separated by 1 week. During the first movement assessment, players were filmed in the frontal and sagittal planes. Ten raters took part in the study (1 experienced rater and 9 novices) and were assigned in a quasirandom manner, to complete either (a) real-time assessment on 2 occasions, (b) real-time assessment on 1 occasion, or (c) video-based assessment on 2 occasions. When assessed in real-time, of the 7 component movements of the AAA, raters registered moderate or greater intrarater agreement on between 2 and 5 occasions. Intraclass correlation coefficients (ICCs) of between 0.50 and 0.61 for the AAA total score indicated poor real-time intrarater reliability for this variable. When assessed by video-recording, raters registered moderate or greater intrarater agreement on between 6 and 7 occasions. The ICC for total score ranged between 0.60 and 0.93. Overall poor interrater reliability was evident for AAA component movements regardless of whether it was assessed in real-time or from video. Findings suggest the AAA is most reliably used when assessed through video. It is recommended that if comparison between multiple raters is desired, a stringent training process be applied so that the interpretation of AAA scoring criteria is standardized across raters.
Publisher: Informa UK Limited
Date: 2002
DOI: 10.1080/026404102317366672
Abstract: In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad x s(-1) and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5+/-7.1 years (mean +/- s). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets x 10 repetitions at 70% body mass load). Strength was reduced for 4 days (P 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6+/-1.1% vs 95.2+/-1.3% of pre-exercise values, P< 0.05) and drop jump (95.2+/-1.4%, P< 0.05) performance. Creatine kinase was elevated (P < 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.
Publisher: Springer Science and Business Media LLC
Date: 08-1995
DOI: 10.1007/BF01046728
Publisher: Informa UK Limited
Date: 06-2012
DOI: 10.1080/02640414.2012.682084
Abstract: This study examined the concurrent effects of exercise-induced muscle damage and superimposed acute fatigue on the neuromuscular activation performance of the knee flexors of nine males (age: 26.7 ± 6.1 years height 1.81 ± 0.05 m body mass 81.2 ± 11.7 kg [mean±s]). Measures were obtained during three experimental conditions: (i) 'fatigue-muscle damage', involving acute fatiguing exercise performed on each assessment occasion plus a single episode of eccentric exercise performed on the first occasion and after the fatigue trial (ii) 'fatigue', involving the fatiguing exercise only and (iii) 'control' consisting of no exercise. Assessments were performed prior to (pre) and at 1 h, 24 h, 48 h, 72 h, and 168 h relative to the muscle damaging eccentric exercise. Repeated-measures analyses of variance (ANOVAs) showed that muscle damage elicited reductions of up to 38%, 24% and 65% in volitional peak force, electromechanical delay and rate of force development compared to baseline and controls, respectively (F ([10, 80]) = 2.3 to 4.6 P < 0.05) with further impairments (6.2% to 30.7%) following acute fatigue (F ([2, 16]) = 4.3 to 9.1 P < 0.05). By contrast, magnetically-evoked electromechanical delay was not influenced by muscle damage and was improved during the superimposed acute fatigue (∼14% F ([2, 16]) = 3.9 P < 0.05). The safeguarding of evoked muscle activation capability despite compromised volitional performance might reveal aspects of capabilities for emergency and protective responses during episodes of fatigue and antecedent muscle damaging exercise.
Publisher: Canadian Science Publishing
Date: 05-2014
Publisher: Oxford University Press
Date: 04-2017
DOI: 10.1093/MED/9780198757672.003.0015
Abstract: As the Borg rating of perceived exertion scale was not appropriate for children, investigators set about developing child-specific scales which employed numbers, words and/or images that were more familiar and understandable. Numerous studies have examined the validity and reliability of such scales as the CERT, PCERT and OMNI amongst children aged 5 to 16 years, across different modes of exercise (cycling, running, stepping, resistance exercise), protocols (intermittent vs. continuous, incremental vs. non-incremental) and paradigms (estimation vs. production). Such laboratory-based research has enabled the general conclusion that children can, especially with practise, use effort perception scales to differentiate between exercise intensity levels, and to self-regulate their exercise output to match various levels indicated by them. However, inconsistencies in the methodological approaches adopted diminish the certainty of some of the interpretations made by researchers. The scope for research in the application of effort perception in physical education and activity/health promotion is considerable.
Publisher: Springer Science and Business Media LLC
Date: 16-04-2015
DOI: 10.1007/S00421-015-3167-Z
Abstract: The American College of Sports Medicine has highlighted the importance of considering the physiological and affective responses to exercise when setting exercise intensity. Here, we examined the relationship between exercise intensity and physiological and affective responses in active older adults. Eighteen participants (60-74 years 64.4 ± 3.9 8 women) completed a maximal graded exercise test (GXT) on a treadmill. Since time to exhaustion in the GXT differed between participants, heart rate (HR), oxygen consumption (VO2), affective valence (affect) and rating of perceived exertion (RPE) were expressed relative to the in idually determined ventilatory threshold (%atVT). During the GXT, VO2, HR and RPE increased linearly (all P 0.05) and became negative towards the end of the test (P < 0.01). In a subsequent session, participants completed a 20-min bout of self-selected exercise (at a preferred intensity). Initially, participants chose to exercise below VT (88.2 ± 17.4 %VO2atVT) however, the intensity was adjusted to work at, or above VT (107.7 ± 19.9 %VO2atVT) after 10 min (P < 0.001), whilst affect remained positive. Together, these findings indicate that exercise around VT, whether administered during an exercise test, or self-selected by the participant, is likely to result in positive affective responses in older adults.
Publisher: Elsevier BV
Date: 05-2003
Publisher: American Physiological Society
Date: 09-2011
DOI: 10.1152/JAPPLPHYSIOL.01021.2010
Abstract: We used 31 P-magnetic resonance spectroscopy to test the hypothesis that exercise-induced muscle damage (EIMD) alters the muscle metabolic response to dynamic exercise, and that this contributes to the observed reduction in exercise tolerance following EIMD in humans. Ten healthy, physically active men performed incremental knee extensor exercise inside the bore of a whole body 1.5-T superconducting magnet before (pre) and 48 h after (post) performing 100 squats with a load corresponding to 70% of body mass. There were significant changes in all markers of muscle damage [perceived muscle soreness, creatine kinase activity (434% increase at 24 h), and isokinetic peak torque (16% decrease at 24 h)] following eccentric exercise. Muscle phosphocreatine concentration ([PCr]) and pH values during incremental exercise were not different pre- and post-EIMD ( P 0.05). However, resting inorganic phosphate concentration ([P i ] pre: 4.7 ± 0.8 post: 6.7 ± 1.7 mM P 0.01) and, consequently, [P i ]/[PCr] values (pre: 0.12 ± 0.02 post: 0.18 ± 0.05 P 0.01) were significantly elevated following EIMD. These mean differences were maintained during incremental exercise ( P 0.05). Time to exhaustion was significantly reduced following EIMD (519 ± 56 and 459 ± 63 s, pre- and post-EIMD, respectively, P 0.001). End-exercise pH (pre: 6.75 ± 0.04 post: 6.83 ± 0.04 P 0.05) and [PCr] (pre: 7.2 ± 1.7 post: 14.5 ± 2.1 mM P 0.01) were higher, but end-exercise [P i ] was not significantly different (pre: 19.7 ± 1.9 post: 21.1 ± 2.6 mM, P 0.05) following EIMD. The results indicate that alterations in phosphate metabolism, specifically the elevated [P i ] at rest and throughout exercise, may contribute to the reduced exercise tolerance observed following EIMD.
Publisher: Springer Science and Business Media LLC
Date: 12-10-2010
DOI: 10.1038/SC.2010.139
Abstract: Each participant completed two submaximal, perceptually guided arm crank exercise tests and a graded exercise test (GXT) to volitional exhaustion. To assess the validity of a submaximal, perceptually guided exercise test to predict peak oxygen uptake (VO(2)peak) during arm cranking in paraplegic in iduals. University of Jordan, Amman, Jordan. Eleven men with paraplegia as a result of poliomyelitis infection or spinal cord injury completed two submaximal perceptually guided exercise tests and an arm crank GXT to volitional exhaustion. The prediction of VO(2)peak was calculated by extrapolating the submaximal rating of perceived exertion (RPE) and VO(2) values by linear regression to RPE20. There were no significant differences between measured and predicted VO(2)peak from the three submaximal ranges of the RPE (that is, 9-13, 9-15 and 9-17) when extrapolated to RPE20 during both perceptually guided exercise tests (all P>0.05). However, the second perceptually guided exercise tests provided a more accurate prediction of VO(2)peak as reflected by narrower 95% limits of agreement and higher intraclass correlation coefficients. This study has shown that VO(2)peak may be predicted with reasonable accuracy from a perceptually guided exercise test, especially after a full familiarization trial.
Publisher: Informa UK Limited
Date: 14-04-2014
DOI: 10.1080/02640414.2014.906045
Abstract: The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ± 11 years 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470-935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m∙min(-1)) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m∙min(-1), muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were ided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: rs (HR) = -.82 (P < .0001) and rs (pain) = -.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.
Publisher: Informa UK Limited
Date: 05-2011
DOI: 10.1080/02640414.2011.561869
Abstract: Power output and heart rate were monitored for 11 months in one female (V(.)O(2max): 71.5 mL · kg⁻¹ · min⁻¹) and ten male (V(.)O(2max): 66.5 ± 7.1 mL · kg⁻¹ · min⁻¹) cyclists using SRM power-meters to quantify power output and heart rate distributions in an attempt to assess exercise intensity and to relate training variables to performance. In total, 1802 data sets were ided into workout categories according to training goals, and power output and heart rate intensity zones were calculated. The ratio of mean power output to respiratory compensation point power output was calculated as an intensity factor for each training session and for each interval during the training sessions. Variability of power output was calculated as a coefficient of variation. There was no difference in the distribution of power output and heart rate for the total season (P = 0.15). Significant differences were observed during high-intensity workouts (P < 0.001). Performance improvements across the season were related to low-cadence strength workouts (P < 0.05). The intensity factor for intervals was related to performance (P < 0.01). The variability in power output was inversely associated with performance (P < 0.01). Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals.
Publisher: Routledge
Date: 25-06-2012
Publisher: Springer Science and Business Media LLC
Date: 08-2017
Publisher: Informa UK Limited
Date: 06-1993
DOI: 10.1080/02640419308729991
Abstract: There is limited information on the accuracy of bioelectrical impedance analysis (BIA) for estimating body composition in children. The purpose of this study was to evaluate BIA measurements for estimating fat mass and fat-free mass in 94 Chinese boys and girls aged 11-17 years. Percent fat (%fatskf) and fat-free mass (FFMskf) were predicted by regression of skinfolds in an equation which is founded on a multicomponent model of body composition in children. Multiple-regression analyses were applied to the data to determine if height2 ided by resistance (resistance index) (RI) could accurately predict FFMskf and %fat. Correlations (R) and predictive accuracy (standard error of the estimate, S.E.E.) for FFMskf for RI alone were 0.94 and 2.7 kg for RI and body mass this improved to 0.96 and 2.2 kg, and for estimation of %fatskf from RI and body mass these values were 0.78 and 4.7%, respectively. A previously published prediction equation, developed on Caucasian children and which also used RI and body mass, was also cross-validated with the Chinese s le in this study. There was no difference between the predicted values from this equation and FFM and %fat predicted by the skinfold technique. The correlation coefficient for FFM was 0.96 and the S.E.E. was similar to that originally reported for the Caucasian s le. We conclude that BIA is a reliable and acceptably accurate method of estimating anthropometrically determined body composition in Chinese youth.
Publisher: Informa UK Limited
Date: 08-1992
DOI: 10.1080/02640419208729932
Abstract: This review describes the phenomenon of delayed onset muscle soreness (DOMS), concentrating upon the types of muscle contraction most likely to produce DOMS and the theories underlying the physiological mechanisms of DOMS. Ways of attempting to reduce the effects of DOMS are also summarized, including the application of physical and pharmacological therapies to reduce the effects of DOMS and training for reduction or prevention of DOMS.
Publisher: Wiley
Date: 07-10-2010
DOI: 10.1111/J.1600-0838.2010.01233.X
Abstract: This study assessed the effect of distance feedback on athletic performance, physiological and perceptual markers and the pacing strategies utilized during treadmill exercise. Thirteen men completed four self-paced 6 km treadmill time trials with either accurate, inaccurate or no distance feedback (NF). Inaccurate time trials involved participants receiving premature (PF) or delayed (DF) feedback, before or following the completion of each kilometer. The provision of accurate or inaccurate distance feedback (PF, DF) did not moderate the completion time or the rate of change in the ratings of perceived exertion (P>0.05). However, completion times were significantly slower when exercising with no distance feedback (P<0.001). Heart rate (HR), oxygen uptake (VO2) and running velocity all increased during the conditions (P<0.001). A significantly lower VO2 (up to 7%) and HR (up to 6%) were observed during NF. This study has demonstrated that athletic performance and perceptual and physiological responses are unaffected by inaccurate distance feedback. However, the study indicates that in iduals may exercise at a lower metabolic intensity when running without distance feedback.
Publisher: Informa UK Limited
Date: 15-01-2008
DOI: 10.1080/02640410701371364
Abstract: The purpose of this study was to assess the validity of predicting the maximal oxygen uptake (VO2(max)) of sedentary men from sub-maximal VO2 values obtained during a perceptually regulated exercise test. Thirteen healthy, sedentary males aged 29-52 years completed five graded exercise tests on a cycle ergometer. The first and fifth test involved a graded exercise test to determine VO2(max). The two maximal graded exercise tests were separated by three sub-maximal graded exercise tests, perceptually regulated at 3-min RPE intensities of 9, 11, 13, 15, and 17 on the Borg ratings of perceived exertion (RPE) scale, in that order. After confirmation that in idual linear regression models provided the most appropriate fit to the data, the regression lines for the perceptual ranges 9-17, 9-15, and 11-17 were extrapolated to RPE 20 to predict VO2(max). There were no significant differences between VO2(max) values from the graded exercise tests (mean 43.9 ml x kg(-1) x min(-1), s = 6.3) and predicted VO2(max) values for the perceptual ranges 9-17 (40.7 ml x kg(-1) x min(-1), s = 2.2) and RPE 11-17 (42.5 ml x kg(-1) x min(-1), s = 2.3) across the three trials. The predicted VO2(max) from the perceptual range 9-15 was significantly lower (P < 0.05) (37.7 ml x kg(-1) x min(-1), s = 2.3). The intra-class correlation coefficients between actual and predicted VO2(max) for RPE 9-17 and RPE 11-17 across trials ranged from 0.80 to 0.87. Limits of agreement analysis on actual and predicted VO2 values (bias +/- 1.96 x S(diff)) were 3.4 ml x kg(-1) x min(-1) (+/- 10.7), 2.4 ml x kg(-1) x min(-1) (+/- 9.9), and 3.7 ml x kg(-1) x min(-1) (+/- 12.8) (trials 1, 2, and 3, respectively) of RPE range 9-17. Results suggest that a sub-maximal, perceptually guided graded exercise test provides acceptable estimates of VO2(max) in young to middle-aged sedentary males.
Publisher: Wiley
Date: 08-09-2011
DOI: 10.1111/J.1469-8986.2011.01287.X
Abstract: The purpose of the study was to objectively measure the exercise intensity associated with affective responses of "good" and "fairly good." In Study 1, 8 active females completed 20 min of affect-regulated exercise to feel "good" or "fairly good" (order counterbalanced) followed by an intensity replication session. On-line gas analysis was used during the replication session to measure the physiological cost of exercising. In Study 2, 10 females completed either 3 trials of exercise to feel "good" (n = 5) or 3 trials to feel "fairly good" (n = 5). Each trial consisted of an affect-regulated session followed by a replication session. Across studies, the intensity to feel "fairly good" was significantly higher than to feel "good." Both intensities lay close to ventilatory threshold. The results add to evidence that women can use affect to regulate intensity and exercise at an intensity that would confer fitness and health benefits if maintained.
Publisher: Springer Science and Business Media LLC
Date: 1987
DOI: 10.1007/BF00640648
Abstract: In the title compound, C(17)H(16)BrN(3)O(2)S, the dihedral angle between the aromatic rings is 1.24 (15)° and the C=N-N=C torsion angle is 167.7 (3)°. The conformation of the thia-zine ring is an envelope, with the S atom displaced by 0.805 (3) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.027 Å). In the crystal, C-H⋯O inter-actions link the mol-ecules into C(10) [010] chains. A weak C-H⋯π inter-action is also observed.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.JSAMS.2016.04.013
Abstract: Choice of accelerometer wear-site may facilitate greater compliance in research studies. We aimed to test whether a simple method could automatically discriminate whether an accelerometer was worn on the hip or wrist from free-living data. Cross-sectional. Twenty-two 10-12y old children wore a GENEActiv at the wrist and at the hip for 7-days. The angle between the forearm and the total acceleration vector for the wrist-worn monitor and between the pelvis and the total acceleration vector for the hip-worn monitor (i.e. the angle between the Y-axis component of the acceleration and the total acceleration vector) was calculated for each 5s epoch. The standard deviation of this angle (SDangle) was calculated over time for the wrist-worn and hip-worn monitor for windows of varying lengths. We hypothesised that the wrist angle would be more variable than the hip angle. Wear site could be discriminated based on SDangle the shorter the time window the lower the optimal threshold and Area under the Receiver-Operating-Characteristic curve (AUROC) for discrimination of wear-site (AUROC=0.833 (1min) - 0.952 (12h)). Classification accuracy was good for windows of 8min (sensitivity=90%, specificity=87%, AUROC=0.92) and plateaued for windows of ≥60min (sensitivity and specificity >90%, AUROC=0.95-0.96). We have presented a robust, computationally simple method that detects whether an accelerometer is being worn on the hip or wrist from 8 to 60min of data. This facilitates the use of wear-site specific algorithms to analyse accelerometer data.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2014
Publisher: Springer Science and Business Media LLC
Date: 06-1989
DOI: 10.1007/BF00666465
Publisher: The Electrochemical Society
Date: 10-1994
DOI: 10.1149/1.2059176
Publisher: Informa UK Limited
Date: 2011
DOI: 10.1080/02640414.2010.526626
Abstract: We tested the hypothesis that exercise-induced muscle damage would increase the ventilatory (V(E)) response to incremental/r cycle exercise (lower the gas exchange threshold) without altering the blood lactate profile, thereby dissociating the gas exchange and lactate thresholds. Ten physically active men completed maximal incremental cycle tests before (pre) and 48 h after (post) performing eccentric exercise comprising 100 squats. Pulmonary gas exchange was measured breath-by-breath and fingertip blood s led at 1-min intervals for determination of blood lactate concentration. The gas exchange threshold occurred at a lower work rate (pre: 136 ± 27 W post: 105 ± 19 W P < 0.05) and oxygen uptake (VO(2)) (pre: 1.58 ± 0.26 litres · min(-1) post: 1.41 ± 0.14 litres · min(-1) P 0.05) and VO(2) (pre: 1.90 ± 0.20 litres · min(-1) post: 1.88 ± 0.15 litres · min(-1) P > 0.05) after eccentric exercise. These findings demonstrate that exercise-induced muscle damage dissociates the V(E) response to incremental/r exercise from the blood lactate response, indicating that V(E) may be controlled by additional or altered neurogenic stimuli following eccentric exercise. Thus, due consideration of prior eccentric exercise should be made when using the gas exchange threshold to provide a non-invasive estimation of the lactate threshold.
Publisher: Springer Science and Business Media LLC
Date: 08-06-2010
DOI: 10.1007/S00421-010-1524-5
Abstract: The purpose of this study was to develop a simple, convenient and indirect method for predicting peak oxygen uptake (VO2peak) from a sub-maximal graded exercise test (GXT), in obese women. Thirty obese women performed GXT to volitional exhaustion. During GXT, oxygen uptake and the power at RPE 15 (VO2peak) were measured, and VO2peak was determined. Following assessment of the relationships between VO2peak and PRPE 15, age, height and mass were made available in a stepwise multiple regression analysis with VO2peak as the dependent variable. The equation to predict VO2peak was: (1 min-1) = 1.355 - 9.920e-3 x age + 8.497e-3 x PRPE 15 (r = 0.83 SEE = 0.156 l min(-1)). This study suggests that age and PRPE 15 elicited during a sub-maximal GXT provides a reasonably accurate prediction of VO2peak in obese women.
Publisher: Springer Science and Business Media LLC
Date: 08-04-2010
DOI: 10.1007/S00421-010-1464-0
Abstract: This study aimed to investigate the efficacy of lower limb compression as a recovery strategy following exercise-induced muscle damage (EIMD). Seventeen female volunteers completed 10 x 10 plyometric drop jumps from a 0.6-m box to induce muscle damage. Participants were randomly allocated to a passive recovery (n = 9) or a compression treatment (n = 8) group. Treatment group volunteers wore full leg compression stockings for 12 h immediately following damaging exercise. Passive recovery group participants had no intervention. Indirect indices of muscle damage (muscle soreness, creatine kinase activity, knee extensor concentric strength, and vertical jump performance) were assessed prior to and 1, 24, 48, 72, and 96 h following plyometric exercise. Plyometric exercise had a significant effect (p < or = 0.05) on all indices of muscle damage. The compression treatment reduced decrements in countermovement jump performance (passive recovery 88.1 +/- 2.8% vs. treatment 95.2 +/- 2.9% of pre-exercise), squat jump performance (82.3 +/- 1.9% vs. 94.5 +/- 2%), and knee extensor strength loss (81.6 +/- 3% vs. 93 +/- 3.2%), and reduced muscle soreness (4.0 +/- 0.23 vs. 2.4 +/- 0.24), but had no significant effect on creatine kinase activity. The results indicate that compression clothing is an effective recovery strategy following exercise-induced muscle damage.
Publisher: Springer Science and Business Media LLC
Date: 03-10-2023
DOI: 10.1007/S00421-022-05047-6
Abstract: To determine the validity and test–retest reliability of using ratings of perceived exertion (RPE) elicited during a submaximal 20-m Shuttle Run Test (20mSRT) to predict VO 2peak in children and investigate acute affective responses. Twenty-five children (14 boys age, 12.8 ± 0.7 years height, 162.0 ± 9.3 cm mass, 49.9 ± 7.7 kg) completed four exercise tests (GXT, 2 submaximal 20mSRT, maximal 20mSRT). The Eston–Parfitt RPE scale was used, and affect was measured with the Feeling Scale. Submaximal 20mSRT were terminated upon participants reporting RPE7. The speed-RPE relationship from the submaximal 20mSRTs was extrapolated to RPE9 and 10 to predict peak speed and then used to estimate VO 2peak . Repeated measures ANOVA to examine the validity of using submaximal RPE to predict VO 2peak resulted in a Gender main effect (boys = 46.7 ± 5.1 mL kg −1 min −1 girls = 42.0 ± 5.1 mL kg −1 min −1 ) and Method main effect ( p 0.01). There were significant differences between measured and estimated VO 2peak from the maximal 20mSRT, but not between measured and estimated VO 2peak at RPE9 and RPE10. Intraclass correlation analysis revealed excellent reliability (~ 0.9) between the two submaximal 20mSRTs. Significant differences ( p 0.05) in end-test affect were reported between submaximal and maximal trials in girls, but not in boys, with girls feeling less negative at the end of the submaximal trials. The results of this study provide evidence that RPE reported during a submaximal 20mSRT can be used to predict VO 2peak accurately and reliably. In this study, the submaximal 20mSRT ending at RPE7, provided better predictions of VO 2peak while minimising aversive end-point affect, especially in girls.
Publisher: Springer Science and Business Media LLC
Date: 20-11-2008
DOI: 10.1007/S00421-008-0935-Z
Abstract: This study evaluated the effects of exercise-induced muscle damage (EIMD) on fixed-load cycling and 5-min time-trial performance. Seven recreational athletes performed two submaximal fixed-load exercise bouts followed by a 5-min time-trial before, 48 and 168 h following 100 counter-movement jumps. Measurements of V(O)(2) heart rate, RER and blood lactate concentration remained unchanged during the fixed-load bouts following jumping exercise. However, VE and VE/VO2 increased (P < 0.05) at 48 h. RPE values were higher at 48 h as were the ratio of RPE:HR and RPE:VO2 (P < 0.05). In the time-trial, mean VO2 peak power output, mean power output, distance covered and post exercise blood lactate were lower at 48 h (P < 0.05). RPE remained unchanged between trials. These findings indicate that the ventilatory equivalent for oxygen and perceived exertion at submaximal work rates are increased 48 h following eccentric exercise. Furthermore, EIMD increases perceived exertion and impairs performance during a 5-min all-out effort.
Publisher: Human Kinetics
Date: 11-2016
Abstract: Athletes often seek the minimum required time that might elicit a physiological or performance change. It is reasonable to suggest that heat training may improve aerobic-based performance in mild conditions. Therefore, rather than providing a traditional heat-exposure stimulus (ie, 7–10 × 60–100 min sessions), the current article details 2 studies that aimed to determine the effect of brief (≤240 min exposure) heat training on the second lactate threshold (LT 2 ) in mild conditions. Forty-one participants completed 5 (study 1, n = 18) or 4 (study 2, n = 23) perceptually regulated treadmill exercise training sessions in 35°C and 30% relative humidity (RH) (experimental group) or 19°C and 30% RH (control group). Preincremental and postincremental exercise testing occurred in mild conditions (19°C and 30% RH). Linear mixed-effects models analyzed the change in LT 2 . Heat training did not substantially change LT 2 in either study 1 (+1.2%, d = 0.38, P = .248) or study 2 (+1.9%, d = 0.42, P = .163). LT 2 was not substantially changed in the control group in study 1 (+1.3%, d = 0.43, P = .193), but a within-group change was evident in study 2 (+2.3%, d = 1.04, P = .001). Brief heat training was inadequate to improve the speed at LT 2 in mild conditions more than comparable training in mild conditions. The brief nature of the heattraining protocol did not allow adaptations to develop to the extent required to potentially confer a performance advantage in an environment that is less thermally stressful than the training conditions.
Publisher: Springer Science and Business Media LLC
Date: 29-04-2023
DOI: 10.1007/S00421-023-05210-7
Abstract: To investigate the efficacy of using Ratings of Perceived Exertion (RPE) to prescribe and regulate a 4-week handcycle training intervention. Thirty active adults, untrained in upper body endurance exercise, were ided into three groups to complete a 4-week intervention: (i) RPE-guided training (n = 10 2 female), (ii) power output (PO)-guided (n = 10 2 female) training, or (iii) non-training control (n = 10 4 female). Training groups performed three sessions of handcycling each week. Oxygen uptake ( $${\\dot{\\text{V}}}O_{2}$$ V ˙ O 2 ), heart rate (HR), and Feeling Scale (FS) rating were collected during training sessions. RPE-guided training was performed at RPE 13. PO-guided training was matched for percentage of peak PO per session, based upon that achieved by the RPE-guided training group. There were no differences in percentage of peak $$\\dot{V}O_{2}$$ V ˙ O 2 (66 ± 13% vs 61 ± 9%, p = 0.22), peak HR (75 ± 8% vs 71 ± 6%, p = 0.11) or FS rating (1.2 ± 1.9 vs 0.8 ± 1.6, p = 0.48) between RPE- and PO-guided training, respectively. The average coefficient of variation in percentage of peak HR between consecutive training sessions was 2.8% during RPE-guided training, and 3.4% during PO-guided training. Moderate-vigorous intensity handcycling exercise can be prescribed effectively using RPE across a chronic training intervention, suggesting utility for practitioners in a variety of rehabilitation settings.
Publisher: Human Kinetics
Date: 02-2019
Abstract: To assess and compare the validity of internal and external Australian football (AF) training-load measures for predicting preseason variation of match-play exercise intensity (MEI sim/min) using a variable dose-response model. A total of 21 professional male AF players completed an 18-wk preseason macrocycle. Preseason internal training load was quntified using the session rating-of-perceived-exertion method (sRPE) and external load from satellite (as distance [Dist] and high-speed distance [HS Dist]) and accelerometer (Player Load [PL]) data. Using a training-impulse (TRIMPs) calculation, external load expressed in arbitrary units was represented as TRIMPs Estimates of MEI sim/min demonstrated very large and large associations with actual MEI sim/min with models constructed from external and internal training inputs (r [90% confidence interval] TRIMPs Variable dose-response models from multiple training-load inputs can predict the within-in idual variation of MEI sim/min across an entire preseason macrocycle. Models informed by external training inputs (TRIMPs
Publisher: Springer Science and Business Media LLC
Date: 31-05-2016
No related grants have been discovered for Roger Eston.