ORCID Profile
0000-0003-1741-718X
Current Organisation
Queensland University of Technology
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Biomedical Engineering Not Elsewhere Classified | Biomechanics | Human Movement and Sports Science | Cardiology (Incl. Cardiovascular Diseases)
Cardiovascular system and diseases | Medical instrumentation | Occupational health (excl. economic development aspects) |
Publisher: Elsevier BV
Date: 03-2023
Publisher: John Wiley & Sons, Ltd
Date: 16-10-2013
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 02-2008
DOI: 10.1167/IOVS.07-0994
Abstract: To measure the effect of acute, mild, systemic hypoxia on neuroretinal function in two different age groups. The slow-flash paradigm of the multifocal electroretinogram (mfERG) was measured in two different oxygenation levels. Twelve participants of two age groups (28 +/- 4 and 55 +/- 5 years) breathed room air (normoxia) or 12% oxygen (hypoxia). During normoxia (SaO(2) = 98%) there was a significantly different effect between the younger and older participants on the mfERG positive waveform components (N1P1 litudes and P1 implicit times P < 0.001). Hypoxia (SaO(2) = 90%) significantly decreased N1P1 response density litudes in the central retinal field in both groups, with a larger effect in the older group (P < 0.001). There was no significant change in function of the cellular generators of oscillatory potentials (OPs). The results extend recent findings by showing a greater effect of hypoxia on ON- and OFF-bipolar cell function in healthy older persons than in younger persons, but no effect on OPs during moderate acute hypoxia in either age group.
Publisher: BMJ
Date: 12-2000
Abstract: Pulmonary diffusing capacity for carbon monoxide (D1co), alveolar capillary membrane diffusing capacity (Dm), and pulmonary capillary blood volume (Vc) are all significantly reduced after exercise. To investigate whether measurement position affects this impaired gas transfer. Before and one, two, and four hours after incremental cycle ergometer exercise to fatigue, single breath D1co, Dm, and Vc measurements were obtained in 10 healthy men in a randomly assigned supine and upright seated position. After exercise, D1co, Dm, and Vc were significantly depressed compared with baseline in both positions. The supine position produced significantly higher values over time for D1co (5.22 (0.13) v. 4.66 (0.15) ml/min/mm Hg/l, p = 0.022) and Dm (6.78 (0.19) v. 6.03 (0.19) ml/min/mm Hg/l, p = 0.016), but there was no significant position effect for Vc. There was a similar pattern of change over time for D1co, Dm, and Vc in the two positions. The change in D1co after exercise appears to be primarily due to a decrease in Vc. Although the mechanism for the reduction in Vc cannot be determined from these data, passive relocation of blood to the periphery as the result of gravity can be discounted, suggesting that active vasoconstriction of the pulmonary vasculature and/or peripheral vasodilatation is occurring after exercise.
Publisher: Wiley
Date: 20-12-2023
Abstract: To examine workload, thermal discomfort and heat‐related symptoms among healthcare workers (HCWs) in an Australian ED during the COVID‐19 pandemic. A cross‐sectional study design was employed among HCWs in an ED at a metropolitan hospital in Brisbane, Australia. Respondents provided demographic information including their self‐reported age, sex, height, weight, role (e.g. doctor, nurse), and whether they wore personal protective equipment (PPE) during their shift, rated as either Full PPE, Partial PPE, or usual uniform or scrubs. The workload of HCWs was assessed with the National Aeronautics and Space Administration's task load index (NASA‐TLX). Thermal discomfort was evaluated using scales from the International Organisation for Standardisation. Responders rated their subjective heat illness using the Environmental Symptoms Questionnaire. Fifty‐nine HCWs completed the survey (27 male, 31 female, one prefer not to answer). Overall workload from the NASA‐TLX was 64.6 (interquartile range [IQR] 56.5–73.3) for doctors, 72.5 (IQR 63.3–83.3) for nurses and 66.7 (IQR 58.3–74.17) for other staff, representing moderate to high ratings. Eighty‐one percent reported thermal sensation to be slightly warm, warm, or hot, and 88% reported being uncomfortable, ranging from slightly to extremely. Ninety‐seven percent reported at least one heat‐strain symptom. More than 50% reported light‐headedness or headache and approximately 30% reported feeling dizzy, faint, or weak. ED HCWs experience thermal discomfort when wearing PPE. Combined with their workloads, HCWs experienced symptoms related to heat strain. Therefore, careful consideration should be given to managing heat strain among HCWs when wearing PPE in an ED.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2018
Publisher: Frontiers Media SA
Date: 09-11-2017
Publisher: Springer Science and Business Media LLC
Date: 30-08-2012
DOI: 10.1007/S00421-011-2143-5
Abstract: The aim of this study was to determine the intraocular pressure response to differing levels of dehydration. Seven males participated in 90 min of treadmill walking (5 km h(-1) and 1% grade) in both temperate (22 °C) and hot (43 °C) conditions. At baseline and 30 min intervals intraocular pressure, nude body mass, body temperature and heart rate were recorded. Statistically significant interactions (p < 0.05) were observed for intraocular pressure (hot condition: baseline 17.0 ± 2.9, 30 min 15.6 ± 3.5, 60 min 14.5 ± 3.7 and 90 min 13.6 ± 2.9 mmHg temperate condition: baseline 16.8 ± 2.7, 30 min 16.5 ± 2.6, 60 min 15.8 ± 2.5 and 90 min 15.7 ± 1.8 mmHg) and body mass loss (hot condition: 30 min -1.07 ± 0.35, 60 min -2.17 ± 0.55 and 90 min -3.13 ± 0.74% temperate condition: 30 min -0.15 ± 0.11, 60 min -0.47 ± 0.18 and 90 min -0.78 ± 0.25%). Significant linear regressions (p < 0.05) were observed for intraocular pressure and body mass loss (adjusted r(2) = 0.24) and intraocular pressure change and body mass loss (adjusted r(2) = 0.51). In conclusion, intraocular pressure was progressively reduced during a period of exercise causing dehydration, but remained relatively stable when hydration was maintained. The present study revealed a moderate relationship between dehydration (body mass loss) and intraocular pressure change.
Publisher: MDPI AG
Date: 21-06-2021
DOI: 10.3390/NU13062124
Abstract: Body water turnover is a marker of hydration status for measuring total fluid gains and losses over a 24-h period. It can be particularly useful in predicting (and hence, managing) fluid loss in in iduals to prevent potential physical, physiological and cognitive declines associated with hypohydration. There is currently limited research investigating the interrelationship of fluid balance, dietary intake and activity level when considering body water turnover. Therefore, this study investigates whether dietary composition and energy expenditure influences body water turnover. In our methodology, thirty-eight males (19 sedentary and 19 physically active) had their total body water and water turnover measured via the isotopic tracer deuterium oxide. Simultaneous tracking of dietary intake (food and fluid) is carried out via dietary recall, and energy expenditure is estimated via accelerometery. Our results show that active participants display a higher energy expenditure, water intake, carbohydrate intake and fibre intake however, there is no difference in sodium or alcohol intake between the two groups. Relative water turnover in the active group is significantly greater than the sedentary group (Mean Difference (MD) [95% CI] = 17.55 g·kg−1·day−1 [10.90, 24.19] p = 0.001 g[95% CI] = 1.70 [0.98, 2.48]). A penalised linear regression provides evidence that the fibre intake (p = 0.033), water intake (p = 0.008), and activity level (p = 0.063) predict participants’ relative body water turnover (R2= 0.585). In conclusion, water turnover is faster in in iduals undertaking regular exercise than in their sedentary counterparts, and is, in part, explained by the intake of water from fluid and high-moisture content foods. The nutrient analysis of the participant diets indicates that increased dietary fibre intake is also positively associated with water turnover rates. The water loss between groups also contributes to the differences observed in water turnover this is partly related to differences in sweat output during increased energy expenditure from physical activity.
Publisher: Springer Science and Business Media LLC
Date: 23-09-2010
DOI: 10.1007/S00421-009-1208-1
Abstract: To investigate whether venous occlusion plethysmography (VOP) may be used to measure high rates of arterial inflow associated with exercise, venous occlusions were performed at rest, and following dynamic handgrip exercise at 15, 30, 45, and 60% of maximum voluntary contraction (MVC) in seven healthy males. The effect of including more than one cardiac cycle in the calculation of blood flow was assessed by comparing the cumulative blood flow over one, two, three, or four cardiac cycles. The inclusion of more than one cardiac cycle at 30 and 60% MVC, and more than two cardiac cycles at 15 and 45% MVC resulted in a lower blood flow compared to using only the first cardiac cycle (P < 0.05). Despite the small time interval over which arterial inflow was measured (~1 s), this did not affect the reproducibility of the technique. Reproducibility (coefficient of variation for arterial inflow over three trials) tended to be poorer at the higher workloads, although this was not significant (12.7 +/- 6.6, 16.2 +/- 7.3, and 22.9 +/- 9.9% for the 15, 30, and 45% MVC workloads P = 0.102). There was also a tendency for greater reproducibility with the inclusion of more cardiac cycles at the highest workload, but this did not reach significance (P = 0.070). In conclusion, when calculated over the first cardiac cycle only during venous occlusion, high rates of forearm blood flow can be measured using VOP, and this can be achieved without a significant decrease in the reproducibility of the measurement.
Publisher: Oxford University Press (OUP)
Date: 02-02-2015
Abstract: Sleep disturbances, including insomnia and sleep-disordered breathing, are a common complaint in people with heart failure and impair well-being. Exercise training (ET) improves quality of life in stable heart failure patients. ET also improves sleep quality in healthy older patients, but there are no previous intervention studies in heart failure patients. The aim of this study was to examine the impact of ET on sleep quality in patients recently discharged from hospital with heart failure. This was a sub-study of a multisite randomised controlled trial. Participants with a heart failure hospitalisation were randomised within six weeks of discharge to a 12-week disease management programme including exercise advice (n=52) or to the same programme with twice weekly structured ET (n=54). ET consisted of two one-hour supervised aerobic and resistance training sessions, prescribed and advanced by an exercise specialist. The primary outcome was change in Pittsburgh Sleep Quality Index (PSQI) between randomisation and week 12. At randomisation, 45% of participants reported poor sleep (PSQI≥5). PSQI global score improved significantly more in the ET group than the control group (-1.5±3.7 vs 0.4±3.8, p=0.03). Improved sleep quality correlated with improved exercise capacity and reduced depressive symptoms, but not with changes in body mass index or resting heart rate. Twelve weeks of twice-weekly supervised ET improved sleep quality in patients recently discharged from hospital with heart failure.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2002
DOI: 10.1097/00042752-200207000-00004
Abstract: The large increase in the number of athletes who apply to use inhaled beta agonists (IBAs) at the Olympic Games is a concern to the medical community. This review will examine the use of IBAs in the asthmatic athlete, the variability that exists between countries and sport, and outline a plan to justify the use of these medications. Much of this article is a result of an International Olympic Committee (IOC) Medical Commission-sponsored meeting that took place in May 2001. Records of the use of IBAs at previous Olympics were reviewed. MEDLINE Searches (PubMed interface) were performed using key words to locate published work relating to asthma, elite athletes, performance, treatment, and ergogenic aids. Since 1984 there have been significant increases in the use of IBAs at the Olympic Games as well as marked geographical differences in the percentage of athletes requesting the use of IBAs. There are large differences in the incidence of IBA use between sports with a trend towards increased use in endurance sports. There are no ergogenic effects of any IOC-approved IBA given in a therapeutic dose. In many cases, the prescription of IBAs to this population has been made on empirical grounds. Beginning with the 2002 Winter Games, athletes will be required to submit to the IOC Medical Commission clinical and laboratory evidence that justifies the use of this medication. The eucapnic voluntary hyperpnea test will be used to assess in iduals who have not satisfied an independent medical panel of the need to use an IBA.
Publisher: Wiley
Date: 18-09-2015
Publisher: American Physiological Society
Date: 07-2023
DOI: 10.1152/JAPPLPHYSIOL.00070.2023
Abstract: Research to date provides equivocal evidence regarding the influence of heat stress, heat strain, and more specifically, elevated exercise-induced core temperature on cognitive performance. This review sought to identify differences in how specific cognitive tasks were affected by increases in core body temperatures. Included papers ( n = 31) measured cognitive performance and core temperature during exercise, while experiencing heightened thermal stress. Cognitive tasks were classified as cognitive inhibition, working memory, or cognitive flexibility tasks. Independently, core temperature changes were not sufficient predictors of cognitive performance. However, reaction time, memory recall, and Stroop tasks appeared to be most effective at identifying cognitive changes during heightened thermal strain. Alterations in performance were more likely to arise under increased thermal loads, which were typically associated with cumulative physiological stressors, such as elevated core temperatures, occurring alongside dehydration, and prolonged exercise durations. Future experimental designs should consider the relevance, or futility of assessing cognitive performance in activities that do not elicit a considerable degree of heat strain, or physiological load.
Publisher: MDPI AG
Date: 28-06-2016
Publisher: Springer Science and Business Media LLC
Date: 19-06-2013
Publisher: Public Library of Science (PLoS)
Date: 06-07-2015
Publisher: Springer Science and Business Media LLC
Date: 12-2009
Abstract: It has been proposed that adenosine triphosphate (ATP) released from red blood cells (RBCs) may contribute to the tight coupling between blood flow and oxygen demand in contracting skeletal muscle. To determine whether ATP may contribute to the vasodilatory response to exercise in the forearm, we measured arterialised and venous plasma ATP concentration and venous oxygen content in 10 healthy young males at rest, and at 30 and 180 seconds during dynamic handgrip exercise at 45% of maximum voluntary contraction (MVC). Venous plasma ATP concentration was elevated above rest after 30 seconds of exercise (P 0.05), and remained at this higher level 180 seconds into exercise (P 0.05 versus rest). The increase in ATP was mirrored by a decrease in venous oxygen content. While there was no significant relationship between ATP concentration and venous oxygen content at 30 seconds of exercise, they were moderately and inversely correlated at 180 seconds of exercise (r = -0.651, P = 0.021). Arterial ATP concentration remained unchanged throughout exercise, resulting in an increase in the venous-arterial ATP difference. Collectively these results indicate that ATP in the plasma originated from the muscle microcirculation, and are consistent with the notion that deoxygenation of the blood perfusing the muscle acts as a stimulus for ATP release. That ATP concentration was elevated just 30 seconds after the onset of exercise also suggests that ATP may be a contributing factor to the blood flow response in the transition from rest to steady state exercise.
Publisher: Wiley
Date: 02-2016
DOI: 10.1111/JEBM.12187
Abstract: Delayed-onset muscle soreness, or 'DOMS', affects many people after exercise and can impair future performance. It usually peaks one to four days after exercise and several strategies are used to overcome it. The effectiveness and safety of many of these strategies applied and promoted is unknown. This article is protected by copyright. All rights reserved.
Publisher: Elsevier BV
Date: 04-2004
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.JSAMS.2018.01.004
Abstract: This study aimed to determine the reliability of 10 and 20km cycling time trial (TT) performance on the Velotron Pro in recreational cyclists, runners and intermittent-sprint based team sport athletes, with and without a familiarisation. Thirty-one male, recreationally active athletes completed four 10 or 20km cycling TTs on different days. During cycling, power output, speed and cadence were recorded at 23Hz, and heart rate and rating of perceived exertion (RPE) were recorded every km. Multiple statistical methods were used to ensure a comprehensive assessment of reliability. Intraclass correlations, standard error of the measurement, minimum difference required for a worthwhile change and coefficient of variation were determined for completion time and mean trial variables (power output, speed, cadence, heart rate, RPE, session RPE). A meaningful change in performance for cyclists, runners, team sport athletes would be represented by 7.5, 3.6 and 12.9% improvement for 10km and a 4.9, 4.0 and 5.6% for 20km completion time. After a familiarisation, a 4.0, 3.7 and 6.4% improvement for 10km and a 4.1, 3.0 and 4.4% would be required for 20km. Data from this study suggest not all athletic subgroups require a familiarisation to produce substantially reliable 10 and 20km cycling performance. However, a familiarisation considerably improves the reliability of pacing strategy adopted by recreational runners and team sport athletes across these distances.
Publisher: Springer Science and Business Media LLC
Date: 12-03-2005
DOI: 10.1007/S00421-005-1319-2
Abstract: This study investigated physiological and psychological correlates of the positive and negative components of a systems model in a well-trained male middle-distance runner. In the systems model, performance at any given point in time is seen as the difference between two antagonistic components, fitness and fatigue, which represent the positive and negative adaptation to training, respectively. Each component comprises a set of parameters unique to the in idual, which were estimated by fitting model-predicted performance to performance measured weekly throughout a 12-week training period. The model fitness component was correlated with extrapolated VO(2max) (ml.kg(-1).min(-1)), running economy (RE) (VO(2) at 17 km.h(-1)), and running speed (km.h(-1)) at ventilatory threshold (VTRS). The model fatigue component was correlated with the fatigue subset of the profile of mood states (POMS). The fit between model and actual performance was significant (r(2)=0.92, P< 0.01). In the case of fitness, both VTRS (r=0.94, P=0.0001) and RE (r=-0.61, P=0.04) were significantly correlated with the model fitness component. There was also a moderate correlation between the fatigue subset of the POMS and the fatigue component (r=0.75, p< 0.05). In summary, this is the first time VTRS and the POMS have been used in an attempt to validate the model components. The findings of the present study support previous validation attempts using biochemical and hormonal markers of fitness and fatigue.
Publisher: Informa UK Limited
Date: 06-01-2021
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.PHYSBEH.2015.04.018
Abstract: Explosive ordnance disposal (EOD) often requires technicians to wear multiple protective garments in challenging environmental conditions. The accumulative effect of increased metabolic cost coupled with decreased heat dissipation associated with these garments predisposes technicians to high levels of physiological strain. It has been proposed that a perceptual strain index (PeSI) using subjective ratings of thermal sensation and perceived exertion as surrogate measures of core body temperature and heart rate, may provide an accurate estimation of physiological strain. Therefore, this study aimed to determine if the PeSI could estimate the physiological strain index (PSI) across a range of metabolic workloads and environments while wearing heavy EOD and chemical protective clothing. Eleven healthy males wore an EOD and chemical protective ensemble while walking on a treadmill at 2.5, 4 and 5.5km·h(-1) at 1% grade in environmental conditions equivalent to wet bulb globe temperature (WBGT) 21, 30 and 37°C. WBGT conditions were randomly presented and a maximum of three randomised treadmill walking trials were completed in a single testing day. Trials were ceased at a maximum of 60-min or until the attainment of termination criteria. A Pearson's correlation coefficient, mixed linear model, absolute agreement and receiver operating characteristic (ROC) curves were used to determine the relationship between the PeSI and PSI. A significant moderate relationship between the PeSI and the PSI was observed [r=0.77 p<0.001 mean difference=0.8±1.1a.u. (modified 95% limits of agreement -1.3 to 3.0)]. The ROC curves indicated that the PeSI had a good predictive power when used with two, single-threshold cut-offs to differentiate between low and high levels of physiological strain (area under curve: PSI three cut-off=0.936 and seven cut-off=0.841). These findings support the use of the PeSI for monitoring physiological strain while wearing EOD and chemical protective clothing. However, future research is needed to confirm the validity of the PeSI for active EOD technicians operating in the field.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 04-2007
DOI: 10.1016/J.CLINPH.2006.12.012
Abstract: This study investigated neuroretinal activity under normoxic and hypoxic conditions with the multifocal electroretinogram (mfERG). We used two mfERG paradigms, the fast flicker and slow flash stimulation modes, to measure neuroretinal activity in five healthy participants who breathed room air and a reduced oxygen mixture (14% oxygen, balance nitrogen). We analysed concentric ring N1P1 and P1N2 response density litudes, the P1 implicit times as well as the local scalar product (SP) response densities. During hypoxia there was a significant reduction of the scalar product response density for the fast flicker (p<0.001) and for the slow flash mfERG (p<0.001). The N1P1 and P1N2 response densities were lower especially for the central three rings although these reductions were not significant between the two oxygen conditions, they indicated an overall distortion of the mfERG waveform. It is demonstrated that a post-receptoral, primarily ON and OFF bipolar cell deficit is evident in the central retina of healthy young people during short term hypoxia. Our findings suggest that persons with pre-existing ischaemic eye disease may be at risk when exposed to hypoxic conditions.
Publisher: IOP Publishing
Date: 06-07-2007
DOI: 10.1088/0967-3334/28/8/009
Abstract: Venous occlusion plethysmography (VOP) is a technique used for the non-invasive measurement of limb blood flow. A fundamental technical consideration of venous occlusion plethysmography is that the limb in question must be placed above heart level. However, in light of advances in technology and methodology, the necessity of this has been questioned. We investigated the validity of the VOP technique with the forearm approximately 10 cm above and below the level of the heart in both resting and dynamic conditions. Nine healthy male participants performed four bouts of handgrip exercise, two at each of 15% and 30% maximum voluntary contraction (MVC) (one above and one below the heart). As hypothesized, resting forearm blood flow (FBF) measured below the level of the heart was significantly lower than for above the heart (p = 0.046). However, the opposite occurred during exercise, where FBF measured after the fifth minute of handgrip contractions was significantly higher below the level of the heart (p = 0.013). Furthermore, the ability to accurately quantify FBF below the level of the heart was severely impeded by artifact, and as such VOP appears to remain constricted to use above the phlebostatic level.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.PHYSBEH.2018.06.026
Abstract: This study examined the effect of environmental temperature deception on the rating of perceived exertion (RPE) during 30 min of fixed-intensity cycling in the heat. Eleven trained male cyclists completed an incremental cycling test and four experimental trials. Trials consisted of 30 min cycling at 50% P RPE was higher in the heat compared to CON, but not statistically different between the hot conditions (mean [95% credible interval] DEC Participants were under the impression they were cycling in different environments however, this did not influence RPE. These data suggest that for trained cyclists, an awareness of environmental temperature does not contribute to the generation of RPE when exercising at a fixed intensity in the heat.
Publisher: Hindawi Limited
Date: 2015
DOI: 10.1155/2015/857536
Abstract: This study evaluated the physiological tolerance times when wearing explosive and chemical ( kg) personal protective equipment (PPE) in simulated environmental extremes across a range of differing work intensities. Twelve healthy males undertook nine trials which involved walking on a treadmill at 2.5, 4, and 5.5 km·h −1 in the following environmental conditions, 21, 30, and 37°C wet bulb globe temperature (WBGT). Participants exercised for 60 min or until volitional fatigue, core temperature reached 39°C, or heart rate exceeded 90% of maximum. Tolerance time, core temperature, skin temperature, mean body temperature, heart rate, and body mass loss were measured. Exercise time was reduced in the higher WBGT environments (WBGT37 WBGT30 WBGT21 P 0.05) and work intensities (5.5 4 2.5 km·h −1 P 0.001). The majority of trials (85/108 78.7%) were terminated due to participant’s heart rate exceeding 90% of their maximum. A total of eight trials (7.4%) lasted the full duration. Only nine (8.3%) trials were terminated due to volitional fatigue and six (5.6%) due to core temperatures in excess of 39°C. These results demonstrate that physiological tolerance times are influenced by the external environment and workload and that cardiovascular strain is the limiting factor to work tolerance when wearing this heavy multilayered PPE.
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.APERGO.2014.08.016
Abstract: The aim of this study was to elucidate the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. Eight healthy males walked on a treadmill for 120 min at 22% of their heart rate reserve in a climate chamber simulating 31 °C (60%RH) wearing either no armour (control), overt or covert PBA in addition to a security guard uniform, in a randomised controlled crossover design. No significant difference between conditions at the end of each trial was observed in core temperature, heart rate or skin temperature (P > 0.05). Covert PBA produced a significantly greater amount of body mass change (-1.81 ± 0.44%) compared to control (-1.07 ± 0.38%, P = 0.009) and overt conditions (-1.27 ± 0.44%, P = 0.025). Although a greater change in body mass was observed after the covert PBA trial based on the physiological outcome measures recorded, the heat strain encountered while wearing lightweight, non-military overt or covert PBA was negligible compared to no PBA. The wearing of bullet proof vests or body armour is a requirement of personnel engaged in a wide range of occupations including police, security, customs and even journalists in theatres of war. This randomised controlled crossover study is the first to examine the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. We conclude that the heat strain encountered while wearing both overt and covert lightweight, non-military PBA was negligible compared to no PBA.
Publisher: University of Technology, Sydney (UTS)
Date: 27-06-2018
Abstract: Retrofitting works has become increasingly important in the construction industry, as it plays an effective role in providing solutions to maintain, upgrade or change the functions to the existing or aged buildings. Very often, safety issues of retrofitting works are underestimated because there may be unreported accidents in small projects and there is no separate classification of accident statistics for the retrofitting works within the construction industry. As safety climate is widely regarded as a contributing factor to safety performance, the aim of this research was to examine the relationship between safety climate and safety performance in retrofitting works context. The safety climate questionnaire NOSACQ-50 has been employed to measure safety climate in retrofitting works. Field patrols were undertaken to distribute the safety questionnaires to the local worksites that undertake retrofits in Brisbane, Queensland, Australia. 264 valid questionnaires were collected. SEM was employed to examine the existence and strength of the relationship between safety climate and safety performance. PLS-SEM was utilised to estimate the parameters of the structural model. The model has exposed a positive relationship between safety climate and safety performance in retrofitting context. This research was the first to examine the relationship between the second order latent variables. A positive relationship (0.60 with 36 percent of explained variance) was found between safety climate and safety performance.
Publisher: Public Library of Science (PLoS)
Date: 21-02-2014
Publisher: Public Library of Science (PLoS)
Date: 09-02-2011
Publisher: Wiley
Date: 23-02-2011
DOI: 10.1111/J.1755-3768.2010.01959.X
Abstract: Flickering stimuli increase the metabolic demand of the retina, making it a sensitive perimetric stimulus to the early onset of retinal disease. We determine whether flickering stimuli are a sensitive indicator of vision deficits resulting from acute, mild systemic hypoxia when compared to standard static perimetry. Static and flicker visual perimetry were performed in 14 healthy young participants while breathing 12% oxygen (hypoxia) under photopic illumination. The hypoxia visual field data were compared with the field data measured during normoxia. Absolute sensitivities (in dB) were analysed in seven concentric rings at 1°, 3°, 6°, 10°, 15°, 22° and 30° eccentricities as well as mean defect (MD) and pattern defect (PD) were calculated. Preliminary data are reported for mesopic light levels. Under photopic illumination, flicker and static visual field sensitivities at all eccentricities were not significantly different between hypoxia and normoxia conditions. The mean defect and pattern defect were not significantly different for either test between the two oxygenation conditions. Although flicker stimulation increases cellular metabolism, flicker photopic visual field impairment is not detected during mild hypoxia. These findings contrast with electrophysiological flicker tests in young participants that show impairment at photopic illumination during the same levels of mild hypoxia. Potential mechanisms contributing to the difference between the visual fields and electrophysiological flicker tests including variability in perimetric data, neuronal adaptation and vascular autoregulation are considered. The data have implications for the use of visual perimetry in the detection of ischaemic/hypoxic retinal disorders under photopic and mesopic light levels.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2003
Publisher: Frontiers Media SA
Date: 12-04-2019
Publisher: Springer Science and Business Media LLC
Date: 05-2021
Abstract: The results of a search for new phenomena in final states with b -jets and missing transverse momentum using 139 fb − 1 of proton-proton data collected at a centre-of-mass energy $$ \\sqrt{s} $$ s = 13 TeV by the ATLAS detector at the LHC are reported. The analysis targets final states produced by the decay of a pair-produced supersymmetric bottom squark into a bottom quark and a stable neutralino. The analysis also seeks evidence for models of pair production of dark matter particles produced through the decay of a generic scalar or pseudoscalar mediator state in association with a pair of bottom quarks, and models of pair production of scalar third-generation down-type leptoquarks. No significant excess of events over the Standard Model background expectation is observed in any of the signal regions considered by the analysis. Bottom squark masses below 1270 GeV are excluded at 95% confidence level if the neutralino is massless. In the case of nearly mass-degenerate bottom squarks and neutralinos, the use of dedicated secondary-vertex identification techniques permits the exclusion of bottom squarks with masses up to 660 GeV for mass splittings between the squark and the neutralino of 10 GeV. These limits extend substantially beyond the regions of parameter space excluded by similar ATLAS searches performed previously.
Publisher: Informa UK Limited
Date: 11-10-2019
DOI: 10.1080/15459624.2019.1666211
Abstract: High levels of exertion and physiological strain are the leading cause of fireground injuries. The Physiological Strain Index (PSI) provides a rating of strain based on body core temperature and heart rate however, it may underestimate the strain of workers in protective clothing as skin temperature may be elevated. This study aimed to examine the relationship between the PSI and an Adaptive Physiological Strain Index (aPSI) that incorporates skin temperature, among firefighters wearing protective clothing. Nine male firefighters of the Australian Defence Force volunteered to participate. Participants conducted scenario-based activities while wearing turnout gear and breathing apparatus. Working in teams of four, participants would respond to a situation around and within a small building with several rooms that could be filled with smoke, however, no live fire was present. Heart rate, gastrointestinal temperature, and skin temperature were monitored throughout work and rehabilitation. Physiological strain was estimated via the PSI and aPSI. Absolute peak PSI and aPSI ratings were significantly different during work (PSI: 7.3 ± 1.6 aPSI 8.2 ± 2.0
Publisher: Elsevier BV
Date: 12-2020
Publisher: Center for Open Science
Date: 24-08-2023
Abstract: Aim: The study aimed to 1) determine the age distribution of Australian volunteer firefighters 2) estimate the proportion of volunteer firefighters who met the Australian physical activity guidelines, using population data as a comparator and 3) investigate the effects of age on physical activity and exercise in volunteer firefighters.Material and methods: A cross-sectional survey was electronically distributed to Rural Fire Service volunteers, in Queensland Australia. The survey included demographic, anthropometric and service questions, in addition to physical activity questions from the 2016–2018 Australian National Health Survey. The Australian guidelines were used to determine whether respondents met the national recommendations for weekly physical activity and exercise only minutes, and strength-based training days. Bayesian generalized linear regression models were used to determine the effect of age on weekly physical activity and exercise only minutes.Results: A total of 480 volunteers responded. The mean age was 51.4 years (95% bootstrap confidence interval = 50.0 to 52.8). Compared to the Australian population, volunteer firefighters were over four times more likely to meet the physical activity guidelines, and the exercise only guidelines but 1.4 times more likely to not meet the strength-based activity guidelines. Physical activity minutes declined with age, by on average 60 minutes each decade. Age had no effect on weekly exercise only minutes.Conclusions: Volunteers were more likely to meet the national physical activity and exercise only guidelines, but less likely to meet the strength-based training guidelines compared to population. Volunteer firefighters could benefit from outreach programs that promote participation in strength-based training.
Publisher: Frontiers Media SA
Date: 27-04-2017
Publisher: Wiley
Date: 14-06-2012
Publisher: American Physiological Society
Date: 05-2017
DOI: 10.1152/JAPPLPHYSIOL.00051.2016
Abstract: Chest wall strapping has been used to assess mechanisms of dyspnea with restrictive lung disease. This study examined the hypothesis that dyspnea with restriction depends principally on the degree of reflex ventilatory stimulation. We compared dyspnea at the same (iso)ventilation when added dead space provided a component of the ventilatory stimulus during exercise. Eleven healthy men undertook a randomized controlled crossover trial that compared four constant work exercise conditions: 1) control (CTRL): unrestricted breathing at 90% gas exchange threshold (GET) 2) CTRL+dead space (DS): unrestricted breathing with 0.6-l dead space, at isoventilation to CTRL due to reduced exercise intensity 3) CWS: chest wall strapping at 90% GET and 4) CWS+DS: chest strapping with 0.6-l dead space, at isoventilation to CWS with reduced exercise intensity. Chest strapping reduced forced vital capacity by 30.4 ± 2.2% (mean ± SE). Dyspnea at isoventilation was unchanged with CTRL+DS compared with CTRL (1.93 ± 0.49 and 2.17 ± 0.43, 0–10 numeric rating scale, respectively P = 0.244). Dyspnea was lower with CWS+DS compared with CWS (3.40 ± 0.52 and 4.51 ± 0.53, respectively P = 0.003). Perceived leg fatigue was reduced with CTRL+DS compared with CTRL (2.36 ± 0.48 and 2.86 ± 0.59, respectively P = 0.049) and lower with CWS+DS compared with CWS (1.86 ± 0.30 and 4.00 ± 0.79, respectively P = 0.006). With unrestricted breathing, dead space did not change dyspnea at isoventilation, suggesting that dyspnea does not depend on the mode of reflex ventilatory stimulation in healthy in iduals. With chest strapping, dead space presented a less potent stimulus to dyspnea, raising the possibility that leg muscle work contributes to dyspnea perception independent of the ventilatory stimulus. NEW & NOTEWORTHY Chest wall strapping was applied to healthy humans to simulate restrictive lung disease. With chest wall strapping, dyspnea was reduced when dead space substituted for part of a constant exercise stimulus to ventilation. Dyspnea associated with chest wall strapping depended on the contribution of leg muscle work to ventilatory stimulation. Chest wall strapping might not be a clinically relevant model to determine whether an alternative reflex ventilatory stimulus mimics the intensity of exertional dyspnea.
Publisher: Informa UK Limited
Date: 13-07-2007
Publisher: Public Library of Science (PLoS)
Date: 22-01-2018
Publisher: Springer Science and Business Media LLC
Date: 08-04-2013
Abstract: Bicycle commuting in an urban environment of high air pollution is known to be a potential health risk, especially for susceptible in iduals. While risk management strategies aimed to reduce exposure to motorised traffic emissions have been suggested, only limited studies have assessed the utility of such strategies in real-world circumstances. The potential to lower exposure to ultrafine particles (UFP 0.1 μm) during bicycle commuting by reducing proximity to motorised traffic was investigated with real-time air pollution and intermittent acute inflammatory measurements in healthy in iduals using their typical higher proximity, and an alternative lower proximity, bicycle commute route. Thirty-five healthy adults (mean ± SD: age = 39 ± 11 yr 29% female) completed two return trips, one each in the condition of their typical route (HIGH) and a pre-determined alternative route of lower proximity to motorised traffic (LOW) proximity being determined by the proportion of on-road cycle paths. Particle number concentration (PNC) and diameter (PD) were monitored in-commute in real-time. Acute inflammatory indices of respiratory symptoms (as a scalar of frequency from very low to very high / 1 to 5), lung function and spontaneous sputum (for inflammatory cell analyses) were collected immediately pre-commute, and immediately and three hours post-commute. In the condition of LOW, compared to in the condition of HIGH, there was a significant decrease in mean PNC (1.91 x e 4 ± 0.93 × e 4 ppcc vs. 2.95 × e 4 ± 1.50 × e 4 ppcc p ≤ 0.001), and the mean frequency of in-commute offensive odour detection (2.1 vs. 2.8 p = 0.019), dust and soot observation (1.7 vs. 2.3 p = 0.038) and nasopharyngeal irritation (1.5 vs. 1.9 p = 0.007). There were no significant differences between LOW and HIGH in the commute distance and duration (12.8 ± 7.1 vs. 12.0 ± 6.9 km and 44 ± 17 vs. 42 ± 17 min, respectively), or other indices of acute airway inflammation. Exposure to PNC and offensive odour, and nasopharyngeal irritation, can be significantly lowered when utilising a route of lower proximity to motorised traffic whilst bicycle commuting, without significantly affecting commute distance or duration. This may bring health benefits for both healthy and susceptible in iduals.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2005
DOI: 10.1249/01.MSS.0000176305.51360.7E
Abstract: To quantify the rate of arterial oxygen desaturation during apnea in free ers. Ten free ers and ten controls undertook five maximal face immersion apneas in 10 degrees C water separated by 2 min of recovery. Electrocardiogram (ECG), blood pressure, and pulse oximetry were recorded continuously. Peripheral blood flow was measured by calf plethysmography every 30 s, and venous blood s les were collected at rest and after apneas 1, 3, and 5. The blood was analyzed for hematocrit (Hct), lactate, and hemoglobin (Hb) concentration. The arterial oxygen saturation (SaO(2)) data were curve fitted with both a sigmoid and two-slope continuous function. Apnea duration increased with successive attempts, with free ers achieving significantly longer maximal apneas (trained 246 +/- 44 s, untrained 129 +/- 39 s, P < 0.001). Compared with controls, free ers displayed a significant change from baseline in heart rate (trained -27.2 +/- 9.5 bpm, untrained -19.7 +/- 9.3 bpm, P < 0.001) and mean arterial pressure (MAP) (trained 48 +/- 20.7 mm Hg, untrained 37 +/- 10.0 mm Hg, P = 0.002), but no difference existed in peripheral blood flow, Hct, lactate, or Hb. The maximal slope of the SaO(2) sigmoid curve was not significantly different between the groups (trained -0.16 +/- 0.05%.s(-1), untrained -0.15 +/- 0.06%.s(-1), P = 0.26), but the DeltaSaO(2(/Deltat obtained from the two-slope continuous model indicated that 85% of the variance in the free ers DeltaSaO(2)/Deltat could be explained by the apnea-induced bradycardia, preapnea vital capacity, and Hb concentration. The sigmoidal function provided no quantifiable difference in the rate of oxygen desaturation. The two-slope continuous method, however, indicated that free ers who had larger oxygen stores and produced the largest bradycardia were able to slow the DeltaSaO(2)/Deltat to two to three times that of the least marked response.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Abstract: A search for charged Higgs bosons decaying into W ± W ± or W ± Z bosons is performed, involving experimental signatures with two leptons of the same charge, or three or four leptons with a variety of charge combinations, missing transverse momentum and jets. A data s le of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb − 1 . The search is guided by a type-II seesaw model that extends the scalar sector of the Standard Model with a scalar triplet, leading to a phenomenology that includes doubly and singly charged Higgs bosons. Two scenarios are explored, corresponding to the pair production of doubly charged H ±± bosons, or the associated production of a doubly charged H ±± boson and a singly charged H ± boson. No significant deviations from the Standard Model predictions are observed. H ±± bosons are excluded at 95% confidence level up to 350 GeV and 230 GeV for the pair and associated production modes, respectively.
Publisher: Informa UK Limited
Date: 10-10-2023
DOI: 10.1080/17461391.2022.2124386
Abstract: This randomized cross-over study tested the hypothesis that heat acclimation training would detrimentally affect sleep variables and alter incidental physical activity compared to a thermoneutral training control condition. Eight recreationally trained males (⩒O
Publisher: Informa UK Limited
Date: 25-04-2016
DOI: 10.1080/00140139.2016.1173233
Abstract: This investigation aimed to quantify metabolic rate when wearing an explosive ordnance disposal (EOD) ensemble (~33kg) during standing and locomotion and determine whether the Pandolf load carriage equation accurately predicts metabolic rate when wearing an EOD ensemble during standing and locomotion. Ten males completed 8 trials with metabolic rate measured through indirect calorimetry. Walking in EOD at 2.5, 4.0 and 5.5km·h
Publisher: Informa UK Limited
Date: 07-01-2020
DOI: 10.1080/17461391.2019.1710264
Abstract: Wellness questionnaires are common in monitoring systems, yet the sensitivity to variations in acute training intensity is unclear. This study examined the controlled dosage effects of differing exercise intensities on wellness variables and subsequent associations with neuromuscular performance. Participants (
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.PHYSBEH.2016.12.009
Abstract: The perceptual strain index (PeSI) has been shown to overcome the limitations associated with the assessment of the physiological strain index (PSI), primarily the need to obtain a core body temperature measurement. The PeSI uses the subjective scales of thermal sensation and perceived exertion (RPE) to provide surrogate measures of core temperature and heart rate, respectively. Unfortunately, thermal sensation has shown large variability in providing an estimation of core body temperature. Therefore, the primary aim of this study was to determine if thermal comfort improved the ability of the PeSI to predict the PSI during exertional-heat stress. Eighteen healthy males (age: 23.5years body mass: 79.4kg maximal aerobic capacity: 57.2ml·kg Significant moderate relationships were observed between the PeSI (r=0.74 p<0.001), the modified PeSI (r=0.73 p<0.001) and unexpectedly RPE (r=0.71 p<0.001) with the PSI, respectively. The PeSI (mean bias: -0.8±1.5 based on a 0-10 scale area under the curve: 0.887), modified PeSI (mean bias: -0.5±1.4 based on 0-10 scale area under the curve: 0.886) and RPE (mean bias: -0.7±1.4 based on a 0-10 scale area under the curve: 0.883) displayed similar predictive performance when participants experienced high-to-very high levels of physiological strain. Modifying the PeSI did not improve the subjective prediction of physiological strain. However, RPE provided an equally accurate prediction of physiological strain, particularly when high-to-very high levels of strain were observed. Therefore, given its predictive performance and user-friendliness, the evidence suggests that RPE in isolation is a practical and cost-effective tool able to estimate physiological strain during exertional-heat stress under these work conditions.
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.APERGO.2021.103586
Abstract: To investigate the effects of repeated work bouts in the heat on peak body core temperature and to explore sex-based differences in body core temperature responses. Fourteen males and fifteen females performed four work bouts (two heavy and two moderate, alternating) in 32.5 °C Wet Bulb Globe Temperature (WBGT), each separated by 30-min seated rest in 28.0 °C WBGT. Participants wore a military combat uniform with body armour and helmet (10 kg load) during the work bouts, removing the vest and helmet during recovery periods. Body core temperature elevation over time was faster in the first compared with subsequent work bouts of each intensity. Body core temperature elevation was similar between males and females during the first heavy work bout, then remained significantly lower in females for the reminder of the trial. Contrary to the assumed progressive elevation in strain, but in agreement with recent literature, a gradual reduction in heat storage in subsequent exercise bouts prevented a cumulative increase in heat strain in the conditions tested.
Publisher: Center for Open Science
Date: 30-03-2023
Abstract: Aim: Prediction intervals are a useful measure of uncertainty for meta-analyses that capture the likely effect size of a new (similar) study based on the included studies. This study aimed to: (i) estimate the proportion of meta-analysis studies that report a prediction interval in sports medicine, using medicine as a comparator and (ii) estimate the proportion of studies with a discrepancy between the reported confidence interval and a calculated prediction interval.Methods: We identified all meta-analysis published between 2012 and 2022 in 10 highly ranked sports medicine and eight medical journals. From these articles, 750 were randomly selected from each discipline. Articles that used a random effect meta-analysis model were included. We randomly selected one meta-analysis from each article to extract data from, which included the number of estimates, the pooled effect, and the confidence and prediction interval.Results: Of the 1500 articles screened, 866 (514 from sports medicine) used a random effect model. The probability of a prediction interval being reported in sports medicine was 1.7% (95% CI = 0.9%, 3.3%). In medicine the probability was 3.9% (95% CI = 2.4%, 6.6%). There were 57% lower odds of a prediction interval being reported in sports medicine (odds ratio = 0.432, 95% CI = 0.178, 0.995). However, the 95% CI was compatible with the difference being practically none. Three of the nine sports medicine studies that reported a prediction interval considered it in their conclusions. A prediction interval was able to be calculated for 220 sports medicine studies. For 60% of these studies, there was a discrepancy in study findings between the reported confidence interval and the calculated prediction interval. Prediction intervals were 3.4 times wider than confidence intervals.Conclusion: Very few meta-analyses report prediction intervals and hence are prone to missing the impact of between-study heterogeneity on the overall conclusions. The widespread misinterpretation of random effect meta-analyses could mean that potentially harmful treatments, or those lacking a sufficient evidence base, are being used in practice. Authors, reviewers, and editors should be aware of the importance of prediction intervals. Journals should consider mandating the inclusion of prediction intervals. Changing the default settings of meta-analysis software to include a prediction interval and changes to the PRISMA reporting guidelines could help improve reporting rates.
Publisher: IOP Publishing
Date: 09-10-2008
Publisher: Portland Press Ltd.
Date: 14-11-2006
DOI: 10.1042/CS20060151
Abstract: Expansion of the capillary network, or angiogenesis, occurs following endurance training. This process, which is reliant on the presence of VEGF (vascular endothelial growth factor), is an adaptation to a chronic mismatch between oxygen demand and supply. Patients with IC (intermittent claudication) experience pain during exercise associated with an inadequate oxygen delivery to the muscles. Therefore the aims of the present study were to examine the plasma VEGF response to acute exercise, and to establish whether exercise training alters this response in patients with IC. In Part A, blood was collected from patients with IC (n=18) before and after (+20 and +60 min post-exercise) a maximal walking test to determine the plasma VEGF response to acute exercise. VEGF was present in the plasma of patients (45.11±29.96 pg/ml) and was unchanged in response to acute exercise. Part B was a training study to determine whether exercise training altered the VEGF response to acute exercise. Patients were randomly assigned to a treatment group (TMT n=7) that completed 6 weeks of high-intensity treadmill training, or to a control group (CON n=6). All patients completed a maximal walking test before and after the intervention, with blood s les drawn as for Part A. Training had no effect on plasma VEGF at rest or in response to acute exercise, despite a significant increase in maximal walking time in the TMT group (915±533 to 1206±500 s P=0.009) following the intervention. The absence of a change in plasma VEGF may reflect altered VEGF binding at the endothelium, although this cannot be confirmed by the present data.
Publisher: Journal of Orthopaedic & Sports Physical Therapy (JOSPT)
Date: 02-1998
DOI: 10.2519/JOSPT.1998.27.2.154
Abstract: Although there is a paucity of scientific support for the benefits of warm-up, athletes commonly warm up prior to activity with the intention of improving performance and reducing the incidence of injuries. The purpose of this study was to examine the role of warm-up intensity on both range of motion (ROM) and anaerobic performance. Nine males (age = 21.7 +/- 1.6 years, height = 1.77 +/- 0.04 m, weight = 80.2 +/- 6.8 kg, and VO2max = 60.4 +/- 5.4 ml/kg/min) completed four trials. Each trial consisted of hip, knee, and ankle ROM evaluation using an electronic inclinometer and an anaerobic capacity test on the treadmill (time to fatigue at 13 km/hr and 20% grade). Subjects underwent no warm-up or a warm-up of 15 minutes running at 60, 70 or 80% VO2max followed by a series of lower limb stretches. Intensity of warm-up had little effect on ROM, since ankle dorsiflexion and hip extension significantly increased in all warm-up conditions, hip flexion significantly increased only after the 80% VO2max warm-up, and knee flexion did not change after any warm-up. Heart rate and body temperature were significantly increased (p < 0.05) prior to anaerobic performance for each of the warm-up conditions, but anaerobic performance improved significantly only after warm-up at 60% VO2max (10%) and 70% VO2max (13%). A 15-minute warm-up at an intensity of 60-70% VO2max is therefore recommended to improve ROM and enhance subsequent anaerobic performance.
Publisher: Wiley
Date: 20-12-2006
DOI: 10.1111/J.1600-0838.2006.00563.X
Abstract: This study examined the effect of prolonged endurance exercise on the development of exercise-induced hypoxemia (EIH) in athletes who had previously displayed EIH during an incremental maximal exercise test. Five male and three female endurance-trained athletes participated. Susceptibility to EIH was confirmed through a maximal incremental exercise test and defined as a reduction in the saturation of arterial oxygen (SpO(2)) of >/=4% from rest. Sixty minutes of running was conducted, on a separate day, at an oxygen consumption corresponding to 95% of ventilatory threshold. Immediately following the 60 min exercise bout, athletes commenced a time trial to exhaustion at 95% maximal oxygen consumption (VO(2max)). The reduction in SpO(2) was significantly greater during the maximal incremental test, than during the 60 min, or time trial to exhaustion (-8.8+/-1.4%, -3.3+/-1.1%, and -4.1+/-2.3%, P<0.05, respectively). The degree of desaturation during the 60 min was significantly related to the relative intensity of exercise at 95% ventilatory threshold (adjusted r(2)=0.54, P=0.02). In conclusion, athletes who did not exercise at greater than 73% VO(2max) during 60 min of endurance exercise did not display EIH, despite being previously susceptible during an incremental maximal test.
Publisher: Public Library of Science (PLoS)
Date: 22-03-2019
Publisher: Center for Open Science
Date: 06-07-2022
Abstract: Aim: We aimed to examine the bias for statistical significance using published confidence intervals in sport and exercise medicine research. Method: The abstracts of 48,390 articles, published in 18 sports and exercise medicine journals between 2002 and 2022, were searched using a validated text-mining algorithm that identified and extracted ratio confidence intervals (i.e., odds ratios, hazard ratios and risk ratios). The text-mining algorithm identified 1,744 abstracts that included ratio confidence intervals, from which 4,484 intervals were extracted. After excluding ineligible intervals, the analysis used 3,819 intervals, reported as 95% confidence intervals, from 1,599 articles. The cumulative distributions of lower and upper confidence limits were plotted to identify any abnormal patterns, particularly around a ratio of 1 (the null hypothesis for a ratio). The distributions were compared to those generated from unbiased reference data, which was not subjected to p-hacking or publication bias. Bias was also investigated using a histogram of z-values calculated from the intervals. Results: There was a marked change in the cumulative distribution of both lower and upper bound intervals just over (lower) and just under (upper) a ratio of 1. Twenty-five percent of lower bound intervals were between 1 and 1.2, which was higher than the 15% observed in the unbiased reference dataset. Sixteen percent of upper bound intervals were between a ratio of 0.9 and 1, which was over four times higher than the unbiased reference dataset. The excess of statistically significant results was also highlighted by the striking absence of z-values between –1.96 and +1.96, corresponding to p-values above 0.05. Conclusion: There was an excess of published research with statistically significant results just below the standard significance threshold of 0.05, which is indicative of publication bias. Transparent research practices, in particular the use of registered reports, are needed to reduce the bias in published sport and exercise medicine research. Researchers and peer reviewers need to direct their focus away from only statistically significant results when evaluating the suitability of manuscripts for publication.
Publisher: Wiley
Date: 07-01-2016
Publisher: Springer Science and Business Media LLC
Date: 12-10-2010
Publisher: Springer Science and Business Media LLC
Date: 22-06-2021
DOI: 10.1186/S40798-021-00334-6
Abstract: Despite an increasing rate of women participating in professional sports, emergency services, and military settings where they are exposed to exertional heat stress, our understanding of female thermoregulation and the detrimental effects of heat on women’s performance, especially regarding the menstrual cycle, is limited. This review aimed to quantify the representation of women in exercise thermoregulation research between 2010 and 2019 and the frequency that these articles reported details pertaining to female participants’ menstrual cycle to determine the volume of novel research that is directly relevant to this growing population. Original exercise thermoregulatory studies published in three major sports medicine databases (PubMed, MEDLINE, and SPORTDiscus) between 2010 and 2019 were surveyed. Articles were screened to determine the number of female and male participants in the study and whether studies involving women reported menstrual orientation or phase. Research involving healthy adult participants and an exercise protocol with a thermoregulatory outcome measure were included in the review. A total of 1407 articles were included in the review, involving 28,030 participants. The annual representation of women ranged from a mean of 11.6% [95% credible interval (CI) 9.2, 14.3] to 17.8% [95% CI 15.2, 20.6] across the 10 years, indicating studies predominantly included men. Nonetheless, there was a small statistical increase in the overall proportion of women, with a mean overall proportion change of 0.7% [95% CI 0.2, 1.2] per year. The increase appeared to be driven by a reduction in the number of studies including only men, rather than studies including more women alongside men, or increased women-only studies. Less than one third of articles involving women reported the menstrual orientation of participants and less than one quarter reported both menstrual orientation and phase. This study shows that women were proportionally underrepresented in exercise thermoregulation research during the past decade and the majority of studies did not report menstrual cycle details of female participants. Researchers should consider including women in future work where their inclusion could contribute meaningful data that enhance the evidence-based and ultimately improves our comprehension of women’s thermal physiology.
Publisher: Informa UK Limited
Date: 29-07-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2008
Publisher: Public Library of Science (PLoS)
Date: 03-10-2018
Publisher: MDPI AG
Date: 29-10-2019
DOI: 10.3390/PROSTHESIS1010004
Abstract: Vertical loading rate could be associated with residuum and whole body injuries affecting in iduals fitted with transtibial prostheses. The objective of this study was to outline one out of five automated methods of extraction of vertical loading rate that stacked up the best against manual detection, which is considered the gold standard during pseudo-prosthetic gait. The load applied on the long axis of the leg of three males was recorded using a transducer fitted between a prosthetic foot and physiotherapy boot while walking on a treadmill for circa 30 min. The automated method of extraction of vertical loading rate, combining the lowest absolute average and range of 95% CI difference compared to the manual method, was deemed the most accurate and precise. The average slope of the loading rate detected manually over 150 strides was 5.56 ± 1.33 kN/s, while the other slopes ranged from 4.43 ± 0.98 kN/s to 6.52 ± 1.64 kN/s depending on the automated detection method. An original method proposed here, relying on progressive loading gradient-based automated extraction, produced the closest results (6%) to manual selection. This work contributes to continuous efforts made by providers of prosthetic and rehabilitation care to generate evidence informing reflective clinical decision-making.
Publisher: Springer Science and Business Media LLC
Date: 07-2021
Abstract: A search for long-lived particles, which have come to rest within the ATLAS detector, is presented. The subsequent decays of these particles can produce high-momentum jets, resulting in large out-of-time energy deposits in the ATLAS calorimeters. These de- cays are detected using data collected during periods in the LHC bunch structure when collisions are absent. The analysed dataset is composed of events from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV and recorded by the ATLAS experiment during 2017 and 2018. The dataset used for this search corresponds to a total live time of 579 hours. The results of this search are used to derive lower limits on the mass of gluino R -hadrons, assuming a branching fraction $$ \\mathcal{B}\\left(\\overset{\\sim }{g}\\to q\\overline{q}{\\chi}_1^0\\right) $$ B g ~ → q q ¯ χ 1 0 = 100%, with masses of up to 1 . 4 TeV excluded for gluino lifetimes of 10 − 5 to 10 3 s.
Publisher: Oxford University Press (OUP)
Date: 15-04-2015
Abstract: Explosive ordnance disposal (EOD) technicians are often required to wear specialized clothing combinations that not only protect against the risk of explosion but also potential chemical contamination. This heavy (>35kg) and encapsulating ensemble is likely to increase physiological strain by increasing metabolic heat production and impairing heat dissipation. This study investigated the physiological tolerance times of two different chemical protective undergarments, commonly worn with EOD personal protective clothing, in a range of simulated environmental extremes and work intensities Seven males performed 18 trials wearing 2 ensembles. The trials involved walking on a treadmill at 2.5, 4, and 5.5 km h(-1) at each of the following environmental conditions, 21, 30, and 37°C wet bulb globe temperature. The trials were ceased if the participants' core temperature reached 39°C, if heart rate exceeded 90% of maximum, if walking time reached 60min or due to volitional fatigue. Physiological tolerance times ranged from 8 to 60min and the duration (mean difference: 2.78min, P > 0.05) were similar in both ensembles. A significant effect for environment (21 > 30 > 37°C wet bulb globe temperature, P 4 > 5.5 km h(-1), P < 0.05) was observed in tolerance time. The majority of trials across both ensembles (101/126 80.1%) were terminated due to participants achieving a heart rate equivalent to greater than 90% of their maximum. Physiological tolerance times wearing these two chemical protective undergarments, worn underneath EOD personal protective clothing, were similar and predominantly limited by cardiovascular strain.
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.JVS.2006.03.037
Abstract: To explore the efficacy of cycle training in the treatment of intermittent claudication, the present study compared performance and physiologic effects of cycle training with more conventional treadmill walking training in a group of patients with claudication. Forty-two in iduals with peripheral arterial disease and intermittent claudication (24 men, 18 women) were stratified by gender and the presence or absence of type 2 diabetes mellitus and then randomized to a treadmill (n = 13), cycle (n = 15), or control group (n = 14). Treadmill and cycle groups trained three times a week for 6 weeks, whereas the control group did not train during this period. Maximal and pain-free exercise times were measured on graded treadmill and cycle tests before and after training. Treadmill training significantly improved maximal and pain-free treadmill walking times but did not improve cycle performance. Cycle training significantly improved maximal cycle time but did not improve treadmill performance. However, there was evidence of a stronger cross-transfer effect between the training modes for patients who reported a common limiting symptom during cycling and walking at baseline. There was also considerable variation in the training response to cycling, and a subgroup of responsive patients in the cycle group improved their walking performance by more than the average response observed in the treadmill group. These findings suggest that cycle exercise is not effective in improving walking performance in all claudication patients but might be an effective alternative to walking in those who exhibit similar limiting symptoms during both types of exercise.
Publisher: Informa UK Limited
Date: 30-06-2020
Publisher: Springer Science and Business Media LLC
Date: 2011
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2015
Publisher: Frontiers Media SA
Date: 08-12-2021
Publisher: Elsevier BV
Date: 12-2012
Publisher: Informa UK Limited
Date: 09-12-2017
DOI: 10.1080/02640414.2016.1262053
Abstract: This study characterises the relationship between gait variability and speed in runners using data from trunk accelerations in each axis. Twelve participants of varying fitness ran on the treadmill with three sessions of six randomly ordered self-selected speeds. A VO
Publisher: Springer Science and Business Media LLC
Date: 30-06-2022
DOI: 10.1007/S00421-022-04991-7
Abstract: Declines in muscle force, power, and contractile function can be observed in older adults, clinical populations, inactive in iduals, and injured athletes. Passive heating exposure (e.g., hot baths, sauna, or heated garments) has been used for health purposes, including skeletal muscle treatment. An acute increase in muscle temperature by passive heating can increase the voluntary rate of force development and electrically evoked contraction properties (i.e., time to peak twitch torque, half-relation time, and electromechanical delay). The improvements in the rate of force development and evoked contraction assessments with increased muscle temperature after passive heating reveal peripheral mechanisms’ potential role in enhancing muscle contraction. This review aimed to summarise, discuss, and highlight the potential role of an acute passive heating stimulus on skeletal muscle cells to improve contractile function. These mechanisms include increased calcium kinetics (release/reuptake), calcium sensitivity, and increased intramuscular fluid.
Start Date: 12-2005
End Date: 06-2008
Amount: $130,000.00
Funder: Australian Research Council
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