Physical Therapy, Sports Therapy and Rehabilitation, Public Health, Environmental and Occupational Health, Multidisciplinary
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Scopus Publications
Scopus Publications
A scoping review of the impact of temperature and humid environmental conditions on drivers’ safety across geographical locations Soonho Koh, Doma Kenji, Wade H. Sinclair, Richard C. Franklin Journal of Public Health Germany, 2026 Aim Road traffic incidents are one of the most significant causes of death globally, with previous research showing that many meteorological factors influence road traffic safety. The purpose of this scoping review was to examine the effect of high ambient temperature and humidity on road traffic incidents across various climatic zones. Subject and methods A search of Ovid MEDLINE, CINAHL, PsycInfo (ProQuest), SafetyLit, and Scopus databases was undertaken to identify studies published between 2002 and 2022, focusing on the association between driver safety, and temperature and humid climate. Available data were extracted and analyzed to evaluate the impact of temperature and humidity on road traffic incidents. Results Forty-eight studies reported on the influence of temperature on driver safety. Two of four studies conducted in polar and subpolar climates reported negative correlations; nine of 11 studies in tropical and subtropical climates reported positive correlations; and 15 studies in temperate climates reported positive whilst five studies reported negative correlations between temperature and traffic incidents. In addition, only ten reported the influence of humidity, and two reported positive correlations, three reported negative correlations, and four reported no significant association. No characteristic tendency was found in the association between humidity and traffic incidents. Conclusion There is an association between climate and road traffic incidents, with increases found in both extreme hot and extreme cold environmental conditions; however, the influence of relative humidity is less evident.
The Acute Effect of Increasing Resistance Training Workload Volume on Muscle Damage Markers and Performance in Heavy Resistance-Trained Youth Athletes Liam Bartlett, Anthony Scott Leicht, Wade Heath Sinclair, Jonathan Douglas Connor, Kenji Doma Sports, 2026 Despite the widespread use of periodized resistance training by athletes, the acute physiological and performance responses when athletes transition between mesocycles with differing workload volumes remain poorly understood. This study examined the acute effect of increasing resistance training workload volume on muscle damage markers and field-specific performance in heavy resistance-trained youth athletes. Eighteen male, rugby league players (age 17.4 ± 0.8 years; body mass 80.2 ± 13.7 kg; height 1.8 ± 0.1 m) completed a four-week mesocycle to develop maximal strength (70–100% of one repetition maximum [1RM]). Muscle damage (i.e., delayed onset muscle soreness [DOMS] and creatine kinase [CK]) and performance measures (i.e., drop jump, plyometric push-up, 40 m sprint and repeated agility) were assessed prior to and at 24 h (T24) and 48 h (T48) following the last session of the strength mesocycle (Week 5). A hypertrophy session (35–70% of 1RM) was then included in Week 6 with data collected prior to and at T24 and T48. Compared with the strength (Week 5) modality, the hypertrophy (Week 6) modality resulted in greater DOMS (41.6 ± 22.7%; effect size [ES] = 0.97–1.12) and modestly higher CK (26.7 ± 47.8%; ES = 0.6). Larger declines in field-specific performance measures were also shown during the HYP modality than STR modality for 20 m sprint performance (−2.1 ± 4.3%; ES = 0.7) and agility performance (−1.1 ± 4.2%; ES = 0.6). There were more modest reductions in drop jump performance (−4.1 ± 7.2%; ES = 0.7) during the HYP modality than in the STR modality, although caution should be given as two separate force plate systems were combined due to technical difficulties. Increasing workload volume was associated with greater muscle damage and modest differences in selected field-specific performance measures following several weeks of maximal strength training. These findings provide preliminary insight into the acute responses to increases in resistance training workload volume. Coaches should monitor athletes’ acute responses during fluctuations in workload volume and consider strategies to help maintain training quality in youth athletes.
Reliability and Divergent Validity of Novel Tools to Assess Occupationally Relevant Performance in Infantry Soldiers Brian E. Heilbronn, Kenji Doma, Wade H. Sinclair, Jace Drain, Jonathan Connor, et al. Journal of Strength and Conditioning Research, 2025 Heilbronn, BE, Doma, K, Sinclair, WH, Drain, J, Connor, J, and Leicht, AS. Reliability and divergent validity of novel tools to assess occupationally relevant performance in infantry soldiers. J Strength Cond Res 39(6): e815–e823, 2025—The primary aim of this study was to determine the reliability and divergent validity of several weighted physical assessments for the Army, including the counter movement jump (CMJ), plyometric push-ups (PPU), an incremental fire and movement assessment (IMFA), and a repeated sprint ability (RSA) test. Male infantry soldiers (n = 30) completed the CMJ, PPU, IFMA, and RSA during both unweighted and weighted conditions with a 48-hour interval between sessions, and then repeated the tests during a weighted condition after a 7-day wash-out period. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) assessed between-session reliability. Divergent validity between weighted and unweighted conditions was determined using Pearson's correlation coefficient (r), with correlation effect size (ES) calculated between the r-values using a Fisher Z-transformation. Good test-retest reliability and divergent validity were demonstrated for most CMJ (ICC 0.50–0.99, CV% 1.18–7.73, ES 0.50–0.69), PPU (ICC 0.61–0.99, CV% 1.03–12.33, ES 0.31–0.68), RSA (ICC 0.50–0.94, CV% 1.34–8.41, ES 0.37–0.75), and IFMA (ICC 0.65–0.94, CV% 2.80–10.99, ES 0.32–0.39) measures. It was concluded that the weighted CMJ, PPU, IMFA, and RSA were reliable tests for Army-specific fitness to determine combat task readiness. Good divergent validity between weighted and unweighted conditions for most test measures supported practitioner's use of weighted assessments for Army-specific capability, while unweighted assessments were recommended for fitness optimization and monitoring training for Army personnel.
Positional Differences in Decision-Making Situations during Professional Rugby League Match-Play Lily Ella Turek, Kenji Doma, Jonathan Douglas Connor, Wade Heath Sinclair Journal of Human Kinetics, 2024 The aim of this study was to explore the types and frequency of decision-making situations of rugby league players during defensive situations and examine whether they were predictive of key performance indicators (KPI). Fifteen elite rugby league matches were coded using notational analysis methods. Specific defensive situations were analysed, including the number of: one-on-one situations with an opposing attacker (1-on-1), two-on-one situations (2-on-1), and combined 1-on-1 and 2-on-1 situations (i.e., total decisions; TDs). There was no relationship between the game outcome and game KPIs for TDs or 1-on-1 decision-making situations. However, successful tackles and missed tackles were predictive of 2-on-1 decision-making situations. Positional differences revealed that back rowers were exposed to the greatest number of decision-making situations, while wingers had the lowest exposure. The total number of decisions and the number of 1-on-1 decisions made by the centres and wingers were significant predictors of line breaks. Additionally, 2-on-1 decisions were significant predictors of line breaks for backrowers. The findings of this study suggest that the type and frequency of decision-making situations in Rugby League are position specific. Practical applications for coaches are discussed to ensure that practice approaches are representative of the various defensive decision-making demands players experience during a game, based on their position.
Acute Response to Training after Returning from the Off-Season in Elite Rugby League Athletes Ryan G Simmons, Anthony Leicht, Wade Heath Sinclair, Paul Bowman, Michael Dobbin, et al. Journal of Human Kinetics, 2024 The purposes of this study were to quantify the physiological response to the initial two-week preseason period in elite male rugby league (RL) athletes, and to determine if a repeated bout effect (RBE) occurs. Eighteen RL players were monitored for the initial two-week preseason period. Blood samples were collected on days (D)1, D2, D4, D5, D8, D9, D11 and D12 to measure creatine kinase (CK). Neuromuscular power was assessed on D1, D5, D8 and D12. During field-based sessions, the external training load was quantified using global positioning system technology, whilst the internal load was quantified using the training impulse and the session rating of perceived exertion. Resistance-based gym session volume was quantified by total repetitions x weight lifted. Perceived measures of fatigue and muscle soreness were assessed on all training days. Two-way (day x week) repeated measures analysis of variance and Bonferroni’s corrected post-hoc tests identified significant changes. There were no significant changes in CK activity (649.2 ± 255.0 vs. 673.8 ± 299.1 µL; p = 0.63) or internal training load measures from week 1 to week 2. External training load measures including total distance (4138.1 ± 198.4 vs. 4525.0 ± 169.2 m; p < 0.001) and repeated high-intensity efforts (12.6 ± 1.8 vs. 17.5 ± 1.8 au; p < 0.001) significantly increased in week 2 compared to week 1. Internal training loads and CK activity did not change in response to an increase in external training loads during the initial preseason. The current results provide support for a ‘real world’ perspective of the RBE phenomenon that may be more applicable for team sport practitioners.
Effect of match-related contextual factors on positional performance in the national rugby league C. J. Wedding, M. A. Gomez, C. T. Woods, W. H. Sinclair, A. S. Leicht International Journal of Sports Science and Coaching, 2023 Objectives To examine the effects of match-related contextual variables on positional groups and success in the National Rugby League (NRL). Methods Data relating to match location, match outcome, quality of opposition and match type (absolute score differential) from all matches across the 2015–2019 NRL seasons were collected, in addition to 14 previously identified Factors (technical performance indicators). A decision tree, grown using the Exhaustive Chi-square Automatic Interaction Detector (CHAID) algorithm, was used to model the effect of each of these match-related contexts on positional contribution according to match outcome. Results The accuracy of the exhaustive CHAID model in explaining the influence of positional groups on match outcome was 66%. The model revealed four primary splits: interchange forwards, utility backs, adjustables and a group containing the remaining three positional groups (forwards, backs, and interchange). Conclusions Results suggest that interchange forwards, utility backs and adjustables could have a definitive role within the team compared to the remaining positional groups in determining match outcome. In contrast to team-level research, there is a greater emphasis on the importance of defensive actions (e.g. try causes, tackles made) at a positional level than attacking performance indicators. The moderate classification accuracy justifies the use of this approach for examination of the interactions between match-related contextual variables, performance indicators and positional groups.
Acute Fatigue Responses to Occupational Training in Military Personnel: A Systematic Review and Meta-Analysis Brian Heilbronn, Kenji Doma, Wade Sinclair, Jonathan Connor, Lachlan Irvine-Brown, et al. Military Medicine, 2023 Introduction Military personnel are required to undertake rigorous physical training to meet the unique demands of combat, often leading to high levels of physiological stress. Inappropriate recovery periods with these high levels of physical stress may result in sub-optimal training and increased risk of injury in military personnel. However, no reviews have attempted to examine the magnitude of training-induced stress following military training activities. The aim of this systematic review was to assess the magnitude of physiological stress (physical, hormonal, and immunological) following task-specific training activities in military personnel. Methods An extensive literature search was conducted within CINAHL, PubMed, Scopus, SportDiscus, and Web of Science databases with 7,220 records extracted and a total of 14 studies eligible for inclusion and evaluation. Study appraisal was conducted using the Kmet scale. Meta-analysis was conducted via forest plots, with standard mean difference (SMD, effect size) and inter-trial heterogeneity (I2) calculated between before (preactivity) and after (12–96 hours postactivity) military-specific activities for biomarkers of physiological stress (muscle damage, inflammation, and hormonal) and physical performance (muscular strength and power). Results Military training activities resulted in significant levels of muscle damage (SMD = −1.28; P = .003) and significant impairments in strength and power (SMD = 0.91; P = .008) and testosterone levels (SMD = 1.48; P = .05) up to 96 hours postactivity. There were no significant differences in inflammation (SMD = −0.70; P = .11), cortisol (SMD = −0.18; P = .81), or insulin-like growth factor 1 (SMD = 0.65; P = .07) when compared to preactivity measures. Conclusions These findings indicate that assessments of muscle damage, anabolic hormones like testosterone, strength, and power are effective for determining the level of acute stress following military-specific activities. With regular monitoring of these measures, appropriate recovery periods may be implemented to optimize training adaptations and occupational performance, with minimal adverse training responses in military personnel.
The Acute Effect of Various Feedback Approaches on Sprint Performance, Motivation, and Affective Mood States in Highly Trained Female Athletes: A Randomized Crossover Trial Larissa Di Bella, Kenji Doma, Wade Heath Sinclair, Jonathan Douglas Connor International Journal of Sports Physiology and Performance, 2023 Purpose: This crossover trial compared the effects of varying feedback approaches on sprint performance, motivation, and affective mood states in female athletes. Methods: Eligibility criteria were being competitive female athletes, where participants completed sprint tests in 4 randomized feedback conditions on grass, including augmented feedback (sprint time; AUG-FB), technical feedback (cues; TECH-FB), a competition-driven drill (CDD) sprinting against an opponent, and a control condition (no feedback; CON). Participants completed a 20-m sprint (maximum sprint), 30-m curved agility sprint, and a repeated sprint ability test, with sprint times, motivation level, and mood states recorded. The participants were blinded from the number of trials during the repeated sprint ability test. Results: About 12 rugby league players completed all feedback conditions. The maximum sprint times were faster for AUG-FB (3.54 [0.16] s) and CDD (3.54 [0.16] s) compared with TECH-FB (3.64 [0.16] s), while there were no differences compared with CON (3.58 [0.17] s). The curved agility sprint times were faster for AUG-FB (5.42 [0.20] s) compared with TECH-FB (5.61 [0.21] s) and CON (5.57 [0.24] s), although CDD (5.38 [0.26] s) produced faster sprint times than TECH-FB. Effort and value were higher with AUG-FB (6.31 [0.68]; 6.53 [0.05]) compared with CON (5.99 [0.60]; 4.75 [2.07]), while CON exhibited lower enjoyment ratings (4.68 [0.95]) compared with other feedback conditions (AUG-FB: 5.54 [0.72]; CDD: 5.56 [0.67]; TECH-FB: 5.60 [0.56]). Conclusions: Providing AUG-FB prior to sprint tasks enhances more immediate performance outcomes than TECH-FB. AUG-FB also benefited athlete enjoyment, task effort, and coaching value. Female athletes should receive AUG-FB in testing and training environments, to improve immediate physical performance and motivation.
Exploring rugby coaches perception and implementation of performance analytics Mikaela J. Callinan, Jonathan D. Connor, Wade H. Sinclair, Anthony S. Leicht Plos One, 2023 Professional coaches commonly rely on performance analysis and metrics to help make decisions regarding their practices, selection and tactics. However, few studies to date have explored coaches’ perspectives of performance analysts successful integration into the high-performance environment. The aim of this study was to investigate coaches’ philosophies surrounding performance analysis and how they perceived analysts could support and implement these approaches into coaching practices and match preparation. Semi-structured interviews were conducted with five professional elite level Rugby Union coaches to investigate their perceptions of performance analysis, and the contribution of performance analysts to the high-performance environment. Results revealed three main dimensions, including the role, purpose, and desired attributes of a performance analyst. Firstly, the role of the analyst was described in terms of being an information specialist, who collects, filters, and delivers information to stakeholders, and a generalist, who helps coaches utilise technology. Secondly, the purpose of the analyst was described in terms of providing both accountability and support for coaches and players. Finally, the attributes needed of an analyst included the ability to form a close relationship with coaches, communicate complex information in meaningful ways, and who was proactive, innovative, and creative when tasked with delivering information. The findings highlighted the crucial roles, purposes, and attributes of a performance analyst within high-performance Rugby Union identified by coaches and the importance of the coach-analyst relationship to support these dimensions.
