ORCID Profile
0000-0002-2484-4019
Current Organisation
Murdoch University
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Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 28-11-2015
DOI: 10.1007/S40279-014-0288-1
Abstract: A growing body of evidence supports the use of moderate blood flow restriction (BFR) combined with low-load resistance exercise to enhance hypertrophic and strength responses in skeletal muscle. Research also suggests that BFR during low-workload aerobic exercise can result in small but significant morphological and strength gains, and BFR alone may attenuate atrophy during periods of unloading. While BFR appears to be beneficial for both clinical and athletic cohorts, there is currently no common consensus amongst scientists and practitioners regarding the best practice for implementing BFR methods. If BFR is not employed appropriately, there is a risk of injury to the participant. It is also important to understand how variations in the cuff application can affect the physiological responses and subsequent adaptation to BFR training. The optimal way to manipulate acute exercise variables, such as exercise type, load, volume, inter-set rest periods and training frequency, must also be considered prior to designing a BFR training programme. The purpose of this review is to provide an evidence-based approach to implementing BFR exercise. These guidelines could be useful for practitioners using BFR training in either clinical or athletic settings, or for researchers in the design of future studies investigating BFR exercise.
Publisher: Human Kinetics
Date: 05-0005
Abstract: To identify contributing factors to the incidence of illness for professional team-sport athletes, using training load (TL), self-reported illness, and well-being data. Thirty-two professional rugby league players (26.0 ± 4.8 y, 99.1 ± 9.6 kg, 1.84 ± 0.06 m) were recruited from the same club. Players participated in prescribed training and responded to a series of questionnaires to determine the presence of self-reported illness and markers of well-being. Internal TL was determined using the session rating of perceived exertion. These data were collected over 29 wk, across the preparatory and competition macrocycles. The predictive models developed recognized increases in internal TL (strain values of AU, weekly TL AU, and monotony .78 AU) to best predict when athletes are at increased risk of self-reported illness. In addition, a reduction in overall well-being ( .25 AU) in the presence of increased internal TL, as previously stated, was highlighted as a contributor to self-reported-illness occurrence. These results indicate that self-report data can be successfully used to provide a novel understanding of the interactions between competition-associated stressors experienced by professional team-sport athletes and their susceptibility to illness. This may help coaching staff more effectively monitor players during the season and potentially implement preventive measures to reduce the likelihood of illnesses occurring.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2019
DOI: 10.1519/JSC.0000000000003007
Abstract: Hughes, LJ, Banyard, HG, Dempsey, AR, Peiffer, JJ, and Scott, BR. Using load-velocity relationships to quantify training-induced fatigue. J Strength Cond Res 33(3): 762–773, 2019—The purpose of this study was to investigate using load-velocity relationships to quantify fluctuations in maximal strength (1 repetition maximum [1RM]), which occur as a result of training-induced fatigue. The 19 well-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, body mass: 84.2 ± 10.5 kg, and squat 1RM: 151.1 ± 25.7 kg) who were recruited for this study attended 5 sessions. After baseline strength testing, in idual load-velocity relationships were established using mean concentric velocity during visits 2, 4, and 5, with visit 3 consisting of a bout of fatiguing exercise (5 sets of squats performed to muscular failure with 70% 1RM). Predicted 1RM values were calculated using the minimal velocity threshold (1RM MVT ), load at zero velocity (1RM LD0 ), and force-velocity (1RM FV ) methods. Measured 1RM, maximal voluntary contractions, and perceived muscle soreness were used to examine the effects of fatigue in relation to the predicted 1RM scores. The 1RM MVT and 1RM LD0 demonstrated very strong and strong correlations with measured 1RM during each of the sessions ( r = 0.90–0.96 and r = 0.77–0.84, respectively), while no strong significant correlations were observed for the 1RM FV . Further analysis using Bland-Altman plots demonstrated substantial interin idual variation associated with each method. These results suggest that load-velocity–based 1RM predictions are not accurate enough to be used for daily training load prescription, as has been previously suggested. Nevertheless, these predictions are practical to implement during an in idual's warm-up and may be useful to indicate general fluctuations in performance potential, particularly if used in conjunction with other common monitoring methods.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2020
DOI: 10.1519/JSC.0000000000002755
Abstract: Lockhart, C, Scott, BR, Thoseby, B, and Dascombe, BJ. Acute effects of interset rest duration on physiological and perceptual responses to resistance exercise in hypoxia. J Strength Cond Res 34(8): 2241–2249, 2020—This study aimed to determine whether manipulating interset rest periods during resistance training in hypoxia impacts on physiological and perceptual responses to exercise. Twelve healthy males completed 1 repetition maximum (1RM) testing for the bilateral leg extension, before completing 4 separate randomized trials comprising 5 × 10 repetitions of leg extensions at 70% 1RM. Experimental trials were completed in both moderate hypoxia (F I O 2 = 15%) and normoxia (F I O 2 = 21%), using interset rest periods of both 60 and 180 seconds for each environmental condition. Near-infrared spectroscopy was used to quantify muscle oxygenation of vastus lateralis , and surface electromyography assessed the activation of vastus lateralis and medialis. Blood lactate concentration ([BLa − ]) and midthigh circumference were assessed before and immediately after each trial. Heart rate (HR) responses, blood oxygen saturation, and rating of perceived exertion (RPE) were also assessed after each set and the whole session RPE (sRPE). Perceived quadriceps soreness was reported before, immediately after, and at 24 and 48 hours after each trial. Muscle activation (sets 4–5), RPE (sets 3–5), and sRPE were significantly ( p 0.05) higher in the 60-second trials of the resistance exercise protocol. Significant increases ( p 0.01) were observed for [BLa − ] and midthigh circumference across sets within each condition. No significant main effect was observed for interset rest duration or environmental condition for muscle oxygenation, HR, or perceived quadriceps soreness. These findings indicate that performing resistance exercise in hypoxia or normoxia with shortened interset rest periods increases muscle activation and perceived exertion, without exacerbating muscle soreness.
Publisher: Informa UK Limited
Date: 11-04-2023
Publisher: Springer Science and Business Media LLC
Date: 17-07-2017
DOI: 10.1038/S41598-017-05953-2
Abstract: Common estimates of external training intensity for resistance exercise do not incorporate inter-set recovery duration, and might not reflect the overall demands of training. This study aimed to assess novel metrics of exercise density (ED) during resistance exercise, and how these related to a physiological marker of internal training intensity as well as traditional measures of external training intensity and volume. Thirteen males and seven females performed two bouts of resistance exercise focused on developing strength (5 sets of 5 repetitions with 5-repetition maximum 180 s recovery) and hypertrophy (3 sets of 10 repetitions with 10-repetition maximum 60 s recovery). Blood lactate concentration was measured to quantify internal training intensity. Specific metrics of external volume (mechanical work, volume load and total repetitions) and intensity (average weight lifted and ED) were calculated. Despite lower average weights and no difference in mechanical work or volume load, blood lactate was greater following hypertrophy compared with the strength condition. This finding was consistent with higher measures of ED in the hypertrophy compared with the strength condition. Greater ED during hypertrophy resistance exercise, along with the significant association with changes in blood lactate, indicates that ED metrics are reflective of the sessional intensity for resistance exercise.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2019
DOI: 10.1519/JSC.0000000000002550
Abstract: Hughes, LJ, Banyard, HG, Dempsey, AR, and Scott, BR. Using a load-velocity relationship to predict one repetition maximum in free-weight exercise: a comparison of the different methods. J Strength Cond Res 33(9): 2409–2419, 2019—The purpose of this study was to investigate the reliability and validity of predicting 1 repetition maximum (1RM) in trained in iduals using a load-velocity relationship. Twenty strength-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, and body mass: 84.2 ± 10.5 kg) were recruited and visited the laboratory on 3 occasions. The load-velocity relationship was developed using the mean concentric velocity of repetitions performed at loads between 20 and 90% 1RM. Predicted 1RM was calculated using 3 different methods discussed in existing research: minimal velocity threshold 1RM (1RM MVT ), load at zero velocity 1RM (1RM LD0 ), and force-velocity 1RM methods (1RM FV ). The reliability of 1RM predictions was examined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). 1RM MVT demonstrated the highest reliability (ICC = 0.92–0.96, CV = 3.6–5.0%), followed by 1RM LD0 (ICC = 0.78–0.82, CV = 8.2–8.6%) and 1RM FV (ICC = −0.28 to 0.00, CV = N/A). Both 1RM MVT and 1RM LD0 were very strongly correlated with measured 1RM ( r = 0.91–0.95). The only method which was not significantly different to measured 1RM was the 1RM LD0 method. However, when analyzed on an in idual basis (using Bland-Altman plots), all methods exhibited a high degree of variability. Overall, the results suggest that the 1RM MVT and 1RM LD0 predicted 1RM values could be used to monitor strength progress in trained in iduals without the need for maximal testing. However, given the significant differences between 1RM MVT and measured 1RM, and the high variability associated with in idual predictions performed using each method, they cannot be used interchangeably therefore, it is recommended that predicted 1RM is not used to prescribe training loads as has been previously suggested.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2014
Publisher: Informa UK Limited
Date: 17-01-2018
DOI: 10.1080/17461391.2017.1421712
Abstract: To determine the effect of limb selection (upper/lower), cuff width (small (6 cm)/medium (13 cm) upper medium/large (18 cm) lower) and anthropometry on arterial occlusion pressure (AOP) in ischemic preconditioning (IPC). Twenty athletes (10 females and 10 males) had surface anthropometry and dual x-ray absorptiometry (DXA) assessments before using Doppler ultrasound to confirm AOP for each limb. Subsequently, 5 min of occlusion occurred, with near-infrared spectroscopy (NIRS) measuring muscle oxygenation changes. Resultant AOP was compared between sexes, limbs and cuff sizes using linear regression models. Mean AOP was higher in the lower limbs than the upper limbs (161 ± 18 vs. 133 ± 12 mm Hg p < .001), and with smaller cuffs in upper (161 ± 16 vs. 133 ± 12 mm Hg p < .001), but not lower limbs (161 ± 16 vs. 170 ± 26 mm Hg p = .222). Sex and resting systolic blood pressure (SBP) accounted for 77% (small cuff) to 83% (medium cuff) of variance in AOP for upper limbs, and 61% (medium cuff) to 63% (large cuff) in lower limbs. Including anthropometry accounted for 82% (small cuff) to 89% (medium cuff) and 78% (medium cuff) to 79% (large cuff) of variance for upper and lower limbs, respectively. Adding DXA variables improved the explained variance up to 83% (small cuff) to 91% (medium cuff) and 79% (medium cuff) to 87% (large cuff) for upper and lower limbs, respectively. NIRS data showed significantly greater tissue oxygenation changes in upper versus lower limbs. The AOP in athletes is dependent on limb occluded, sex, SBP, limb and cuff size, and body composition.
Publisher: Frontiers Media SA
Date: 15-05-2019
Publisher: Termedia Sp. z.o.o.
Date: 31-08-2020
Abstract: Redistributing long inter-set rest intervals into shorter but more frequent rest intervals generally maintains concentric performance, possibly due to improved energy store maintenance. However, eccentric actions require less energy than concentric actions, meaning that shorter but more frequent sets may not affect eccentric actions to the same degree as concentric actions. Considering the increased popularity of eccentric exercise, the current study evaluated the effects of redistributing long inter-set rest periods into shorter but more frequent rest periods during eccentric only knee extensions. Eleven resistance-trained men performed 40 isokinetic unilateral knee extensions at 60°·s −1 with 285 s of total rest using traditional sets (TS 4 sets of 10 with 95 s inter-set rest) and rest-redistribution (RR 20 sets of 2 with 15 s inter-set rest). Before and during exercise, muscle oxygenation was measured via near-infrared spectroscopy, and rating of perceived exertion (RPE) was recorded after every 10 th repetition. There were no differences between protocols for peak torque (RR, 241.58±47.20 N TS, 231.64±48.87 N p=0.396) or total work (RR, 215.26±41.47 J TS, 209.71±36.02 J p=0.601), but moderate to large effect sizes existed in later repetitions (6,8,10) with greater peak torque during RR (d=0.66-1.19). For the entire session, RR had moderate effects on RPE (RR, 5.73±1.42 TS, 6.09±1.30 p=0.307 d=0.53) and large effects on oxygen saturation (RR, 5857.4±310.0 TS, 6495.8±273.8 p=0.002, d=2.13). Therefore, RR may maintain peak torque or total work during eccentric exercise, improve oxygen utilization at the muscle, and reduce the perceived effort.
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.JELEKIN.2014.07.008
Abstract: This study quantified the inter- and intra-test reliability of telemetric surface electromyography (EMG) and near infrared spectroscopy (NIRS) during resistance exercise. Twelve well-trained young men performed high-intensity back squat exercise (12 sets at 70-90% 1-repetition maximum) on two occasions, during which EMG and NIRS continuously monitored muscle activation and oxygenation of the thigh muscles. Intra-test reliability for EMG and NIRS variables was generally higher than inter-test reliability. EMG median frequency variables were generally more reliable than litude-based variables. The reliability of EMG measures was not related to the intensity or number of repetitions performed during the set. No notable differences were evident in the reliability of EMG between different agonist muscles. NIRS-derived measures of oxyhaemoglobin, deoxyhaemoglobin and tissue saturation index were generally more reliable during single-repetition sets than multiple-repetition sets at the same intensity. Tissue saturation index was the most reliable NIRS variable. Although the reliability of the EMG and NIRS measures varied across the exercise protocol, the precise causes of this variability are not yet understood. However, it is likely that biological variation during multi-joint isotonic resistance exercise may account for some of the variation in the observed results.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.JSAMS.2015.04.014
Abstract: This study aimed to collate current evidence regarding the efficacy of various blood flow restriction (BFR) strategies for well-trained athletes, and to provide insight regarding how such strategies can be used by these populations. Review article. Studies that had investigated the acute or adaptive responses to BFR interventions in athletic participants were identified from searches in MEDLINE (PubMed), SPORTDiscus (EBSCO) and Google Scholar databases up to April 2015. The reference lists of identified papers were also examined for relevant studies. Twelve papers were identified from 11 separate investigations that had assessed acute and adaptive responses to BFR in athletic cohorts. Of these, 7 papers observed enhanced hypertrophic and/or strength responses and 2 reported alterations in the acute responses to low-load resistance exercise when combined with BFR. One paper had examined the adaptive responses to moderate-load resistance training with BFR, 1 noted improved training responses to low-work rate BFR cardiovascular exercise, and 1 reported on a case of injury following BFR exercise in an athlete. Current evidence suggests that low-load resistance training with BFR can enhance muscle hypertrophy and strength in well-trained athletes, who would not normally benefit from using light loads. For healthy athletes, low-load BFR resistance training performed in conjunction with normal high-load training may provide an additional stimulus for muscular development. As low-load BFR resistance exercise does not appear to cause measureable muscle damage, supplementing normal high-load training using this novel strategy may elicit beneficial muscular responses in healthy athletes.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.BURNS.2021.03.002
Abstract: Major burn patients have been shown to exhibit a hyper-metabolic state of activity which can persist for up to two years after burn. The relationship between total body surface area (TBSA) and resting metabolic rate (RMR) has been investigated in larger burns (≥20% TBSA), however not in non-severe burns (≤15% TBSA). The primary aim of this observational study was to examine the association between the acute effects of burns <15% TBSA with RMR in patients using indirect calorimetry, as well as any potential covariates. The secondary aim was to determine 24-h energy balance. The study included data from 39 participants (82% male), all admitted to the State Adult Burn Unit at Fiona Stanley Hospital. Each patient was recruited upon admission and RMR data was collected on day four (± one day) after burn. The pooled data bivariate correlation showed a significant relationship between RMR and TBSA (r=0.435, p=0.009). A stronger relationship was also found between RMR and TBSA in males (r=0.634, p=0.001). Patients recorded a caloric deficit of 116kcal/day. This study demonstrated that a moderately strong linear association exists between RMR and TBSA in males for burns of ≤15% TBSA. The energy balance data indicated that supplementation of calorific intake for non-severe burns suggests careful consideration.
Publisher: Frontiers Media SA
Date: 10-2018
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.JSAMS.2018.01.013
Abstract: Blood flow restriction (BFR) during interval cycling may stimulate aerobic and anaerobic adaptations. However, acute physiological responses to BFR interval cycling have not been extensively investigated. Eighteen males completed low-intensity (LI), low-intensity with BFR (LI During LI BP, HR, CO, V˙O LI
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2017
DOI: 10.1519/JSC.0000000000001671
Abstract: Scott, BR, Peiffer, JJ, and Goods, PSR. The effects of supplementary low-load blood flow restriction training on morphological and performance-based adaptations in team sport athletes. J Strength Cond Res 31(8): 2147–2154, 2017—Low-load resistance training with blood flow restriction (BFR) may be a method to enhance muscular development even in trained athletes. This study aimed to assess whether supplemental low-load BFR training can improve muscle size, strength, and physical performance characteristics in team sport athletes. Twenty-one semiprofessional Australian football athletes were assessed for 3-repetition maximum (3RM) and muscular endurance in the back squat, vastus lateralis muscle architecture, and performance in sprint and vertical jump tasks. Participants then undertook a 5-week training program, consisting of normal high-load resistance training supplemented by low-load squats with (LL BFR ) or without (LL) BFR. Participants also performed regular conditioning and football training during this period. After the training intervention, participants again completed the pretraining testing battery. Squat 3RM and endurance increased from pretraining levels in both LL (3RM = 12.5% increase endurance = 24.1% increase p ≤ 0.007) and LL BFR (3RM = 12.3% increase endurance = 21.2% increase p = 0.007) groups, though there were no between-group differences. No post-training changes were observed for muscle architecture, or performance in sprinting and jumping tasks. Although squat 3RM and endurance performance increased in both groups, adding BFR during supplemental exercise did not enhance these responses. Similarly, there were no large differences in the assessments of sprint, acceleration, and jumping performance between the groups after training. These findings suggest that although LL BFR did not negatively affect adaptive responses to resistance training, this training strategy may not provide added benefit for healthy Australian football athletes already undertaking a rigorous training schedule.
Publisher: Informa UK Limited
Date: 18-10-2018
DOI: 10.1080/17461391.2017.1388850
Abstract: Recent studies have reported that resistance training in hypoxia (RTH) may augment muscle size and strength development. However, consensus on the effects of RTH via systematic review and meta-analysis is not yet available. This work aimed to systematically review studies which have investigated using RTH versus normoxic resistance training (NRT) to improve muscular size and strength, and to perform a meta-analysis to determine the effect of RTH on these adaptive parameters. Searches were conducted in PubMed, Web of Science and the Cochrane Library from database inception until 17 June 2017 for original articles assessing the effects of RTH on muscle size and strength versus NRT. The effects on outcomes were expressed as standardized mean differences (SMD). Nine studies (158 participants) reported on the effects of RTH versus NRT for muscle cross-sectional area (CSA) (n = 4) or strength (n = 6). RTH significantly increased CSA (SMD = 0.70, 95% confidence intervals (CI) 0.05, 1.35 p = .04) and strength (SMD = 1.88 95% CI = 1.20, 2.56 p < .00001). However, RTH did not produce significant change in CSA (SMD = 0.24, 95% CI -0.19, 0.68, p = .27) or strength (SMD = 0.20 95% CI = -0.27, 0.78 p = .23) when compared to NRT. Although RTH improved muscle size and strength, this protocol did not provide significant benefit over resistance training in normoxia. Nevertheless, this paper identified marked differences in methodologies for implementing RTH, and future research using standardized protocols is therefore warranted.
Publisher: Human Kinetics
Date: 06-2023
Abstract: Purpose : This study examined the influence of blood-flow restriction (BFR) on the distribution of pace, physiological demands, and perceptual responses during self-paced cycling. Methods : On separate days, 12 endurance cyclists/triathletes were instructed to produce the greatest average power output during 8-minute self-paced cycling trials with BFR (60% arterial occlusion pressure) or without restriction (CON). Power output and cardiorespiratory variables were measured continuously. Perceived exertion, muscular discomfort, and cuff pain were recorded every 2 minutes. Results : Linear regression analysis of the power output slope was statistically significant (ie, deviated from the intercept) for CON (2.7 [3.2] W·30 s −1 P = .009) but not for BFR (−0.1 [3.1] W·30 s −1 P = .952). Absolute power output was ∼24% (12%) lower at all time points ( P .001) during BFR compared with CON. Oxygen consumption (18% [12%] P .001), heart rate (7% [9%] P .001), and perceived exertion (8% [21%] P = .008) were reduced during BFR compared with CON, whereas muscular discomfort (25% [35%] P = .003) was greater. Cuff pain was rated as “strong” (5.3 [1.8] au 0–10 scale) for BFR. Conclusion : Trained cyclists adopted a more even distribution of pace when BFR was applied compared with a negative distribution during CON. By presenting a unique combination of physiological and perceptual responses, BFR is a useful tool to understand how the distribution of pace is self-regulated.
Publisher: Informa UK Limited
Date: 08-08-2023
Publisher: Frontiers Media SA
Date: 22-10-2019
Publisher: Informa UK Limited
Date: 14-05-2023
DOI: 10.1080/17461391.2022.2062056
Abstract: This study examined cardiovascular, perceptual and neuromuscular fatigue characteristics during and after cycling intervals with and without blood flow restriction (BFR). Fourteen endurance cyclists/triathletes completed four 4-minute self-paced aerobic cycling intervals at the highest sustainable intensity, with and without intermittent BFR (60% of arterial occlusion pressure). Rest interval durations were six, four and four minutes, respectively. Power output, cardiovascular demands and ratings of perceived exertion (RPE) were averaged over each interval. Knee extension torque and
Publisher: SAGE Publications
Date: 08-2016
Abstract: This study investigated the correlations between the skill demands of an ‘on-side’ small-sided game (SSG) and match-play in under-16 junior rugby league players. Fifteen Harold Matthews players undertook a SSG (10 vs. 10 on a 68 m by 40 m playing surface for 3 min) in the week leading up to round 6 of their competitive season. The frequency of skill involvements (i.e. offensive, defensive and total) was manually coded using a specific criterion. The defensive and total skill involvements were significantly higher per minute of play in the SSG when compared to match-play. A significant, very large, positive correlation was observed between offensive and total skill involvements during a SSG and offensive skill involvements during a match (r (s) = 0.80, p 0.01 r (s) = 0.71, p 0.01, respectively). No significant correlations were evident for defensive skill involvements during SSG and match-play. Overall, it appears that the selected SSG provided players with le opportunity to practice match-specific skills. In addition, the transfer of these opportunities seems confined to offensive rather then defensive skills.
Publisher: Frontiers Media SA
Date: 30-10-2020
Publisher: Springer Science and Business Media LLC
Date: 03-09-2018
DOI: 10.1007/S40279-018-0981-6
Abstract: Adolescent cricket pace bowlers are prone to non-contact shoulder, low back and lower-limb injuries. Exercise-based injury prevention programmes (IPPs) are effective for reducing non-contact injuries in athletes however, a specific programme for adolescent pace bowlers has not been published. This paper therefore seeks to provide a rationale for the development of an exercise-based IPP specific for adolescent pace bowlers. It also outlines design principles and provides an ex le exercise programme that can be implemented at the community level. In addition, the paper addresses other injury prevention techniques concerned with the prescription of appropriate bowling loads and the modification of poor bowling biomechanics. Performing an exercise-based IPP before cricket training could reduce injury rates in adolescent pace bowlers. Eccentric strengthening exercises can be employed to target injuries to the posterior shoulder muscles, hip adductors and hamstring muscles. The risk of low back, knee and ankle injury could also be reduced with the inclusion of dynamic neuromuscular control exercises and trunk extensor endurance exercises. Other prevention strategies that need to be considered include the modification of poor bowling biomechanics, such as shoulder counter-rotation and lateral trunk flexion. Coaches and players should also aim to quantify bowling load accurately and coaches should use this information to prescribe appropriate in idualised bowling loads. Specifically, players would benefit from avoiding both long periods of low load and acute periods when load is excessively high. Future evidence is needed to determine the effectiveness of the ex le programme outlined in this paper. It would also be beneficial to investigate whether the modification of bowling biomechanics is achievable at the non-elite level and if bowling load can be accurately measured and manipulated within a community-level population.
Publisher: Springer Science and Business Media LLC
Date: 23-07-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2017
DOI: 10.1519/JSC.0000000000001649
Abstract: Scott, BR, Slattery, KM, Sculley, DV, Lockhart, C, and Dascombe, BJ. Acute physiological responses to moderate-load resistance exercise in hypoxia. J Strength Cond Res 31(7): 1973–1981, 2017—This study assessed whether hypoxia augments anabolic responses to moderate-load resistance exercise. Fourteen trained men performed moderate-load resistance exercise in normoxia (NORM fraction of inspired oxygen [F I O 2 ] = 21%) and moderate-level hypoxia (MH F I O 2 = 16%). Exercise comprised 3 sets of 10 repetitions of squats and deadlifts at 60% of 1 repetition maximum, with 60-second interset rest. Blood lactate (BLa − ) was quantified after each exercise, whereas arterial oxygen saturation and heart rate (HR) were assessed after each set. Thigh circumference was measured before and after exercise. Muscle activation and oxygenation were monitored by surface electromyography (EMG) and near-infrared spectroscopy, respectively. Relative BLa − concentrations were significantly higher following squats ( p = 0.041) and deadlifts ( p = 0.002) in MH than NORM. Arterial oxygen saturation was lower after each set in MH compared with NORM ( p 0.001), although HR and thigh circumference were not different between conditions. Integrated EMG was higher in MH than in NORM for the squat during several repetitions ( p ≤ 0.032). Measures of muscle oxygen status were not significantly different between conditions ( p ≥ 0.247). The main findings from this study suggest that hypoxia during moderate-load resistance exercise augments metabolite accumulation and muscle activation. However, a significant hypoxic dose was not measured at the muscle, possibly because of the moderate level of hypoxia used. The current data support previous hypotheses that have suggested hypoxia can augment some physiological responses that are important for muscular development, and may therefore provide benefit over the equivalent training in normoxia.
Publisher: Elsevier BV
Date: 05-2020
DOI: 10.1016/J.JSAMS.2019.12.009
Abstract: To investigate if an exercise-based injury prevention program (IPP) can modify risk factors for injury in community-level adolescent cricket pace bowlers. Cluster-randomised controlled trial. Eight cricket organisations (training two times per week and no previous involvement in a structured IPP) participated in this cluster-randomised trial. Participants were aged 14-17 years, injury free, and not currently performing a rehabilitation/exercise program. Cricket organisations (clusters) were block-randomised by computerised number generation into an intervention group (performed an eight-week IPP at training) or control group (continued their usual cricket activity). Participants were not blinded to group allocation. Strength, endurance, and neuromuscular control were assessed at baseline and follow-up. Treatment effects were estimated using linear mixed models. Sixty-five male adolescent pace bowlers (intervention n=32 and control n=33) were randomised. There were significant treatment effects favouring the intervention group for shoulder strength (90°/s) 0.05 (95% CI 0.02-0.09) Nm/kg, hamstring strength (60°/s) 0.32 (95% CI 0.13-0.50) Nm/kg, hip adductor strength dominant 0.40 (95% CI 0.26-0.55) Nm/kg and non-dominant 0.33 (95% CI 0.20-0.47) Nm/kg, SEBT reach distance dominant 3.80 (95% CI 1.63-6.04) percent of leg length (%LL) and non-dominant 3.60 (95% CI 1.43-5.78) %LL, and back endurance 20.4 (95% CI 4.80-36.0) seconds. No differences were observed for shoulder strength (180°/s) (p=0.09), hamstring strength (180°/s) (p=0.07), lumbopelvic stability (p=0.90), and single leg squat knee valgus angle (dominant p=0.06, non-dominant p=0.15). Exercise-based IPPs can modify risk factors for injury in community-level adolescent pace bowlers. Future research is needed to confirm if IPPs can also reduce injury risk in this population.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2020
Publisher: Canadian Science Publishing
Date: 04-2020
Abstract: This study investigated redistributing long inter-set rest intervals into shorter but more frequent intervals at 2 different concentric velocities. Resistance-trained men performed 4 randomised isokinetic unilateral knee extension protocols, 2 at 60°·s −1 and 2 at 360°·s −1 . At each speed, subjects performed 40 repetitions with 285 s of rest using traditional sets (TS 4 sets of 10 with 95 s of inter-set rest) and rest-redistribution (RR 20 sets of 2 with 15 s inter-set rest). Before and at 2, 5, and 10 min after exercise, tensiomyography (TMG) and oxygenation (near-infrared spectroscopy NIRS) were measured. NIRS was also measured during exercise, and rating of perceived exertion (RPE) was recorded after every 10 repetitions. At both speeds, RR displayed greater peak torque, total work, and power output during latter repetitions, but there were no differences between TS or RR when averaging all 40 repetitions. The RPE was less during RR at both speeds (p 0.05). RR increased select muscle oxygen saturation and blood flow at both speeds. There were no effects of protocol on TMG, but effect sizes favoured a quicker recovery after RR. RR was likely beneficial in maintaining performance compared with the latter parts of TS sets and limiting perceived and peripheral fatigue. Novelty Although effective at slow velocities, rest-redistribution was likely more effective during high-velocity movements in this study. Rest-redistribution maintained the ability to produce force throughout an entire range of motion. Rest-redistribution reduced RPE during both high-velocity and high-force movements.
Publisher: Springer Science and Business Media LLC
Date: 16-01-2016
DOI: 10.1007/S40279-015-0454-0
Abstract: Resistance exercise is difficult to quantify owing to its inherent complexity with numerous training variables contributing to the training dose (type of exercise, load lifted, training volume, inter-set rest periods, and repetition velocity). In addition, the intensity of resistance training is often inadequately determined as the relative load lifted (% 1-repetition maximum), which does not account for the effects of inter-set recovery periods, repetition velocity, or the number of repetitions performed in each set at a given load. Methods to calculate the volume load associated with resistance training, as well as the perceived intensity of in idual sets and entire training sessions have been shown to provide useful information regarding the actual training stimulus. In addition, questionnaires to subjectively assess how athletes are coping with the stressors of training and portable technologies to quantify performance variables such as concentric velocity may also be valuable. However, while several methods have been proposed to quantify resistance training, there is not yet a consensus regarding how these methods can be best implemented and integrated to complement each other. Therefore, the purpose of this review is to provide practical information for strength coaches to highlight effective methods to assess resistance training, and how they can be integrated into a comprehensive monitoring program.
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.MEHY.2014.12.001
Abstract: Traditionally, researchers and practitioners have manipulated acute resistance exercise variables to elicit the desired responses to training. However, recent research indicates that altering the muscular environment during resistance training, namely by implementing a hypoxic stimulus, can augment muscle hypertrophy and strength. Intermittent hypoxic resistance training (IHRT), whereby participants inspire hypoxic air during resistance training, has been previously demonstrated to increase muscle cross-sectional area and maximum strength by significantly greater amounts than the equivalent training in normoxia. However, some recent evidence has provided conflicting results, reporting that the use of systemic hypoxia during resistance training provided no added benefit. While the definitive mechanisms that may augment muscular responses to IHRT are not yet fully understood, an increased metabolic stress is thought to be important for moderating many downstream processes related to hypertrophy. It is likely that methodological differences between conflicting IHRT studies have resulted in different degrees of metabolic stress during training, particularly when considering the inter-set recovery intervals used. Given that the most fundamental physiological stresses resulting from hypoxia are disturbances to oxidative metabolism, it becomes apparent that resistance training may only benefit from additional hypoxia if the exercise is structured to elicit a strong metabolic response. We hypothesize that for IHRT to be more effective in producing muscular hypertrophy and increasing strength than the equivalent normoxic training, exercise should be performed with relatively brief inter-set recovery periods, with the aim of providing a potent metabolic stimulus to enhance anabolic responses.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2016
DOI: 10.1519/JSC.0000000000001563
Abstract: Scott, BR, Hodson, JA, Govus, AD, and Dascombe, BJ. The 30-15 Intermittent Fitness Test: can it predict outcomes in field tests of anaerobic performance? J Strength Cond Res 31(10): 2825–2831, 2017—This study determined whether a composite assessment of intermittent fitness could be used to quantify performance in several anaerobic tasks. Fifty-two male recreational athletes (age: 24.3 ± 4.4 years body mass: 85.1 ± 12.2 kg height: 180.5 ± 7.0 cm) were recruited from various team sports. Participants completed a battery of field tests to assess sprinting speed (40-m sprint), acceleration ability (10-m sprint), change of direction speed (505 test), anaerobic capacity (300-m shuttle), lower-body power (vertical jump), and repeated-sprint ability and the 30-15 Intermittent Fitness Test to determine the velocity of intermittent fitness (V IFT ). Relationships between anaerobic tests and V IFT were quantified via Pearson product-moment correlations, and a 2-predictor model multiple linear regression estimated the predictive relationships between the exercise tests and the V IFT . Multiple linear regression showed that V IFT significantly predicted 56, 51, 44, 36, 12, and 1% of the variance in the 300-m shuttle, repeated sprint, 505- and 40-m sprint, vertical jump, and 10-m sprint tests, respectively. The 2-predictor model determined the 300-m shuttle, and repeated-sprint performance accounted for 67% of the variance in V IFT . These findings highlight that various anaerobic characteristics contribute to the intermittent fitness qualities that are quantified through V IFT . More specifically, these data indicate that V IFT is useful for tracking performance in tasks largely determined by anaerobic capacity, but may not be a good predictor of brief all-out sprinting and jumping efforts.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-06-2022
DOI: 10.1519/JSC.0000000000004079
Abstract: Smith, NDW, Scott, BR, Girard, O, and Peiffer, JJ. Aerobic training with blood flow restriction for endurance athletes: potential benefits and considerations of implementation. J Strength Cond Res 36(12): 3541–3550, 2022—Low-intensity aerobic training with blood flow restriction (BFR) can improve maximal oxygen uptake, delay the onset of blood lactate accumulation, and may provide marginal benefits to economy of motion in untrained in iduals. Such a training modality could also improve these physiological attributes in well-trained athletes. Indeed, aerobic BFR training could be beneficial for those recovering from injury, those who have limited time for training a specific physiological capacity, or as an adjunct training stimulus to provide variation in a program. However, similarly to endurance training without BFR, using aerobic BFR training to elicit physiological adaptations in endurance athletes will require additional considerations compared with nonendurance athletes. The objective of this narrative review is to discuss the acute and chronic aspects of aerobic BFR exercise for well-trained endurance athletes and highlight considerations for its effective implementation. This review first highlights key physiological capacities of endurance performance. The acute and chronic responses to aerobic BFR exercise and their impact on performance are then discussed. Finally, considerations for prescribing and monitoring aerobic BFR exercise in trained endurance populations are addressed to challenge current views on how BFR exercise is implemented.
Publisher: Human Kinetics
Date: 08-2022
Abstract: This study compared training loads and internal:external load ratios from an aerobic interval session at the highest perceptually sustainable intensity with and without blood flow restriction (BFR). On separate days, 14 endurance cyclists/triathletes completed four 4-minute self-paced aerobic cycling intervals at their highest sustainable intensity, with and without BFR (60% of arterial occlusion pressure). Internal training load was quantified using 3 training impulses (TRIMP Banister, Lucia, and Edwards) and sessional ratings of perceived exertion. External load was assessed using total work done (TWD). Training load ratios between all internal loads were calculated relative to TWD. Lucia TRIMP was lower for the BFR compared with non-BFR session (49 [9] vs 53 [8] arbitrary units [au], P = .020, dz = -0.71). No between-conditions differences were observed for Banister TRIMP (P = .068), Edwards TRIMP (P = .072), and training load in sessional ratings of perceived exertion (P = .134). The TWD was lower for the BFR compared with non-BFR session (223 [52] vs 271 [58] kJ, P < .001, dz = -1.27). Ratios were greater for the BFR session compared with non-BFR for Lucia TRIMP:TWD (0.229 [0.056] vs 0.206 [0.056] au, P < .001, dz = 1.21), Edwards TRIMP:TWD (0.396 [0.105] vs 0.370 [0.088] au, P = .031, dz = 0.66), and training load in sessional ratings of perceived exertion:TWD (1.000 [0.266] vs 0.890 [0.275] au, P = .044, dz = 0.60), but not Banister TRIMP:TWD (P = .306). Practitioners should consider both internal and external loads when monitoring BFR exercise to ensure the demands are appropriately captured. These BFR-induced changes were reflected by the Lucia TRIMP:TWD and Edwards TRIMP:TWD ratio, which could be used to monitor aerobic BFR training loads. The Lucia TRIMP:TWD ratio likely represents BFR-induced changes more appropriately compared with ratios involving either Edwards or Banister TRIMP.
Publisher: Public Library of Science (PLoS)
Date: 05-10-2023
Publisher: Springer Science and Business Media LLC
Date: 29-08-2019
DOI: 10.1007/S00421-019-04217-3
Abstract: This study quantified performance, physiological, and perceptual responses during resistance exercise to task failure with blood flow restriction (BFR), in systemic hypoxia, and with these stimuli combined. Fourteen young men were tested for 1-repetition maximum (1RM) in the barbell biceps curl and lying triceps extension exercises. On separate visits, subjects performed exercise trials (4 sets to failure at 70% 1RM with 90 s between sets) in six separate randomized conditions, i.e., in normoxia or hypoxia (fraction of inspired oxygen = 20.9% and 12.9%, respectively) combined with three different levels of BFR (0%, 45%, or 60% of resting arterial occlusion pressure). Muscle activation and oxygenation were monitored via surface electromyography and near-infrared spectroscopy, respectively. Arterial oxygen saturation, heart rate, and perceptual responses were assessed following each set. Compared to set 1, the number of repetitions before failure decreased in sets 2, 3, and 4 for both exercises (all P 0.065). Arterial oxygen saturation was lower with systemic hypoxia (P 0.341). Muscle oxygenation and activation during exercise trials remained unaffected by the different conditions (all P ≥ 0.206). A significant main effect of time, but not condition, was observed for overall perceived discomfort, difficulty breathing, and limb discomfort (all P < 0.001). Local and systemic hypoxic stimuli, or a combination of both, did not modify the fatigue-induced change in performance, trends of muscle activation or oxygenation, nor exercise-related sensations during a multi-set resistance exercise to task failure.
Publisher: Wiley
Date: 28-07-2018
DOI: 10.1111/CPF.12451
Abstract: This study assessed whether hypoxia during high-load resistance exercise could enhance the acute physiological responses related to muscular development. Twelve trained men performed exercise in three conditions: normoxia (fraction of inspired oxygen [F
Publisher: Frontiers Media SA
Date: 13-10-2014
Publisher: Human Kinetics
Date: 2023
Publisher: Informa UK Limited
Date: 15-07-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2012
Publisher: Frontiers Media SA
Date: 27-12-2016
Publisher: Human Kinetics
Date: 03-2013
Abstract: To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer. Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 in idual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA .4 km/h], high-speed running [HSR .4 km/h], very high-speed running [VHSR .8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product–moment correlations. Physical measures of TD, LSA volume, and player load provided large, significant ( r = .71−.84 P .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant ( r = .40−.67 P .01) correlations with measures of internal TL. While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2014
Publisher: Informa UK Limited
Date: 08-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2017
DOI: 10.1519/JSC.0000000000002304
Abstract: Scott, BR, Slattery, KM, Sculley, DV, and Dascombe, BJ. Hypoxia during resistance exercise does not affect physical performance, perceptual responses, or neuromuscular recovery. J Strength Cond Res 32(8): 2174–2182, 2018—This study aimed to determine whether performing resistance exercise in hypoxia affects markers of physical performance, perceptual responses, and neuromuscular function. Fourteen male subjects (age: 24.6 ± 2.7 years height: 179.7 ± 5.9 cm body mass: 84.6 ± 11.6 kg) with years resistance training experience performed moderate-load resistance exercise in 2 conditions: normoxia (F I O 2 = 0.21) and hypoxia (F I O 2 = 0.16). Resistance exercise comprised 3 sets of 10 repetitions of back squats and deadlifts at 60% of 1 repetition maximum (1RM), with 60 seconds inter-set rest. Physical performance was assessed by quantifying velocity and power variables during all repetitions. Perceptual ratings of perceived exertion, physical fatigue, muscle soreness, and overall well-being were obtained during and after exercise. Neuromuscular performance was assessed by vertical jump and isometric mid-thigh pull (IMTP) tasks for up to 48 hours after exercise. Although physical performance declined across sets, there were no differences between conditions. Similarly, perceived exertion and fatigue scores were not different between conditions. Muscle soreness increased from baseline at 24 and 48 hours after exercise in both conditions ( p ≤ 0.001). Jump height and IMTP peak force were decreased from baseline immediately after exercise ( p ≤ 0.026), but returned to preexercise values after 24 hours. These findings suggest that hypoxic resistance exercise does not affect exercise performance or perceived exercise intensity. In addition, neuromuscular recovery and perceptual markers of training stress were not affected by hypoxia, suggesting that hypoxic resistance training may not add substantially to the training dose experienced.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-12-2019
Publisher: Informa UK Limited
Date: 14-12-2016
DOI: 10.1080/02640414.2015.1122206
Abstract: This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were sub ided into hit-up forwards, adjustables and outside backs. The frequency (n · min(-1)) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06 P < 0.001 ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player's positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2015
Publisher: Springer Science and Business Media LLC
Date: 09-04-2014
DOI: 10.1007/S40279-014-0177-7
Abstract: It is generally believed that optimal hypertrophic and strength gains are induced through moderate- or high-intensity resistance training, equivalent to at least 60% of an in idual's 1-repetition maximum (1RM). However, recent evidence suggests that similar adaptations are facilitated when low-intensity resistance exercise (~20-50% 1RM) is combined with blood flow restriction (BFR) to the working muscles. Although the mechanisms underpinning these responses are not yet firmly established, it appears that localized hypoxia created by BFR may provide an anabolic stimulus by enhancing the metabolic and endocrine response, and increase cellular swelling and signalling function following resistance exercise. Moreover, BFR has also been demonstrated to increase type II muscle fibre recruitment during exercise. However, inappropriate implementation of BFR can result in detrimental effects, including petechial haemorrhage and dizziness. Furthermore, as BFR is limited to the limbs, the muscles of the trunk are unable to be trained under localized hypoxia. More recently, the use of systemic hypoxia via hypoxic chambers and devices has been investigated as a novel way to stimulate similar physiological responses to resistance training as BFR techniques. While little evidence is available, reports indicate that beneficial adaptations, similar to those induced by BFR, are possible using these methods. The use of systemic hypoxia allows large groups to train concurrently within a hypoxic chamber using multi-joint exercises. However, further scientific research is required to fully understand the mechanisms that cause augmented muscular changes during resistance exercise with a localized or systemic hypoxic stimulus.
Publisher: Springer Science and Business Media LLC
Date: 06-09-2017
DOI: 10.1007/S40279-017-0778-Z
Abstract: Adolescent cricket pace bowlers are prone to injury. Recognising the risk factors for non-contact injury in this population will aid future injury prevention strategies. To identify the risk factors for non-contact injury in adolescent cricket pace bowlers. We systematically searched PubMed, Cochrane Library, PEDro, SPORTDiscus, Embase, and the South African Journal of Sports Medicine to identify all experimental and observational studies reporting risk factors for non-contact injuries in pace bowlers (aged 12-19 years). The search syntax included terms relevant to cricket bowling, injury, and known risk factors for injury. The Newcastle-Ottawa Quality Assessment Scale and a modified Newcastle-Ottawa Quality Assessment Scale were used to assess the risk of bias in the cohort and cross-sectional studies, respectively. Sixteen studies (five cross-sectional studies, 11 cohort studies) comprising 687 participants (96% male, 75% playing cricket in Australia) met the selection criteria and were included for qualitative synthesis. Three cross-sectional studies were rated as high risk of bias and two as very high risk of bias. For the cohort studies, three were rated as low risk of bias, and eight as high risk of bias. Injury was associated with bowling biomechanics (excessive lateral trunk flexion and pelvis/hip kinematics), reduced trunk endurance, poor lumbo-pelvic-hip movement control, and early signs of lumbar bone stress. Conflicting results were found by studies examining the mixed technique, bowling workload and quadratus lumborum asymmetry. The current systematic review identified a number bowling biomechanics and various neuromuscular deficiencies as risk factors for non-contact injury in adolescent pace bowlers. These factors may provide a useful target for future interventional research aiming to prevent injury in this population. Future studies should utilise prospective cohort designs, and ensure that participants are injury-free at baseline, confounding factors are well controlled and attrition rates are reported. This systematic review was registered a priori (PROSPERO, CRD42016043956).
No related grants have been discovered for Brendan Scott.