Science of Sport, Exercise and Physical Activity in the Tropics

The Greek philosopher Aristotle first suggested the earth could be divided into types of climatic zones, based on their distance from the equator. The region nearest the equator was termed the Torrid Zone and was considered uninhabitable. However, almost half of the world's population now live, exercise and regularly compete in this Torrid Zone, which in modern times, we recognize as the tropics. This book is the first text to report the mechanisms, interventions, implications and practical considerations of sport, exercise and physical activity in the tropics. Tropical conditions impose a unique blend of challenges to human physical performance and these areas are thoroughly interrogated in this monograph. Pertinent commentaries of physiology, behavior, sports and physical activity considerations in hot, humid, tropical conditions are provided. These are additionally supported by peer-reviewed cutting edge research articles to maximize performance in the tropics

The effects of mood status and competitive anxiety in elite basketball players

Interest has developed in studying the relationship between pre-competitive mood and anxiety with athletic performance (eg. Beedie, Terry & Lane, 2000; Morgan, Ellickson, O'Connor & Bradley, 1992). The most commonly used instrument for measuring mood states in sport psychology is the Profile of Mood States (POMS). A weak to moderate relationship exists between pre-competitive mood and the performance of similarly skilled athletes (Cox, 2002). The current study examined the relationship between pre-game mood status (POMS), competitive-anxiety (SCAT), task-ego orientation (TEOSQ) and game statistics during the season of an elite basketball competition

Assessment of Inter-Instrument Reliability for Dominant Handgrip Dynamometry and Spirometry

Purpose: The aim of this study was to determine the inter-instrument reliability of different dynamometers and spirometers commonly used in clinical practice. Methods: The study involved 113 healthy volunteers across three facility sites. At each site, dominant handgrip strength (DHGS), and lung function (forced expiratory volume in one second [FEV1], forced vital capacity [FVC] and peak expiratory flow rate [PEFR]), were compared using a local and reference device. Assessments were randomized with five minutes rest between measurements. Significant differences between devices were assessed using paired t-test while relative reliability between devices was determined via intra-class correlations (ICC). Accuracy index and variability between measurements were assessed using the technical error of measurement (TEM%) and coefficient of variation (CV), respectively. Agreement between devices was determined using the Bland Altman’s plot with limits of agreement (LOA). Results: The local devices recorded significantly (p<0.05) lower mean values for DHGS (7.3-18%), FEV1 (3.1%-8.4%), FVC (3.1%-13%) compared to the reference devices. Good-excellent correlations (ICC=0.89-0.96), unacceptable CV (5.8-9.9%) and TEM% (6.6-9.9%), and large mean biases (3-9kg) and LOA (3-23kg) were identified between the local and reference dynamometers. Excellent correlations (ICC=0.91-0.99), and mostly unacceptable CV and TEM% were identified between the local and reference spirometers for FVC and PEFR. Compared to the reference device, all local spirometers showed unacceptable (-0.134 to -0.536 liters) and acceptable (-0.12 to 0.05 liters/second) mean biases for FVC and PEFR, respectively. Conclusion: Unacceptable inter-instrument reliability was identified between local and reference dynamometers and spirometers for measuring DHGS and all lung function indices, respectively. Across clinical settings, comparing DHGS and lung function between different brands of devices may lead to the reporting of erroneous results with corrective adjustments required for clinical practice

Assessment of Inter-Instrument Reliability for Dominant Handgrip Dynamometry and Spirometry

Purpose: The aim of this study was to determine the inter-instrument reliability of different dynamometers and spirometers commonly used in clinical practice. Methods: The study involved 113 healthy volunteers across three facility sites. At each site, dominant handgrip strength (DHGS), and lung function (forced expiratory volume in one second [FEV1], forced vital capacity [FVC] and peak expiratory flow rate [PEFR]), were compared using a local and reference device. Assessments were randomized with five minutes rest between measurements. Significant differences between devices were assessed using paired t-test while relative reliability between devices was determined via intra-class correlations (ICC). Accuracy index and variability between measurements were assessed using the technical error of measurement (TEM%) and coefficient of variation (CV), respectively. Agreement between devices was determined using the Bland Altman’s plot with limits of agreement (LOA). Results: The local devices recorded significantly (p1 (3.1%-8.4%), FVC (3.1%-13%) compared to the reference devices. Good-excellent correlations (ICC=0.89-0.96), unacceptable CV (5.8-9.9%) and TEM% (6.6-9.9%), and large mean biases (3-9kg) and LOA (3-23kg) were identified between the local and reference dynamometers. Excellent correlations (ICC=0.91-0.99), and mostly unacceptable CV and TEM% were identified between the local and reference spirometers for FVC and PEFR. Compared to the reference device, all local spirometers showed unacceptable (-0.134 to -0.536 liters) and acceptable (-0.12 to 0.05 liters/second) mean biases for FVC and PEFR, respectively. Conclusion: Unacceptable inter-instrument reliability was identified between local and reference dynamometers and spirometers for measuring DHGS and all lung function indices, respectively. Across clinical settings, comparing DHGS and lung function between different brands of devices may lead to the reporting of erroneous results with corrective adjustments required for clinical practice

Convergent validity and reliability of a novel repeated agility protocol in junior rugby league players

Background: : Rugby league involves repeated, complex, and high intensity change-of-direction (COD) movements with no existing test protocols that specifically assesses these multiple physical fitness components simultaneously. Thus, the current study examined the convergent validity of a repeated Illinois Agility (RIA) protocol with the repeated T-agility protocol, and the repeatability of the RIA protocol in adolescent Rugby League players. Furthermore, aerobic capacity and anaerobic and COD performance were assessed to determine whether these physical qualities were important contributors to the RIA protocol. Methods: Twenty-two junior Rugby League players completed 4 sessions with each separated by 7 days. Initially, physical fitness characteristics at baseline (i.e., Multi-stage Shuttle test, countermovement jump, 30-m sprint, single-effort COD and repeated sprint ability [RSA]) were assessed. The second session involved a familiarisation of RIA and repeated T-agility test (RTT) protocols. During the third and fourth sessions, participants completed the RIA and RTT protocols in a randomised, counterbalanced design to examine the validity and test-retest reliability of these protocols. Results: For convergent validity, significant correlations were identified between RIA and RTT performances (r= >0.80; p0.71; p < 0.05). Reliability of the RIA protocol was near perfect with excellent intra-class correlation coefficient (0.87-0.97), good ratio limits of agreement (×/÷ 1.05-1.06) and low coefficient of variations (1.8-2.0%). Conclusions: The current study has demonstrated the RIA to be a simple, valid and reliable field test for RL athletes that can provide coaches with information about their team’s ability to sustain high intensity, multi-directional running efforts

Intra-Session Reliability of Sprint Performance on a Non-Motorised Treadmill for Healthy Active Males and Females

This study examined the intra-session reliability of sprint performance on a non-motorized treadmill amongst healthy, active male and female adults. One hundred and twenty participants (males n = 77; females n = 45) completed two familiarization sessions, followed by a third session that consisted of three trials (T1, T2, T3) of maximal sprints (4-s), interspersed by three minutes of recovery. Combining males and females exhibited moderate-to-excellent test-retest reliability (intra-class correlation coefficient, ICC), minimal measurement error (coefficient of variation, CV) and trivial differences between trials (effect size, ES) for speed, power, total work and acceleration (ICC = 0.82–0.98, CV = 1.31–8.45%, ES = 0.01–0.22). The measurement error was improved between comparisons of T1 vs. T2 (CV = 1.62–8.45%, ES = 0.12–0.22) to T2 vs. T3 (CV = 1.31–6.56%, ES = 0.01–0.07) and better for females (CV = 1.26–7.94%, ES = 0.001–0.26) than males (CV = 1.33–8.53%, ES = 0.06–0.31). The current study demonstrated moderate-to-excellent reliability and good-moderate measurement error during a 4-s sprint on a non-motorized treadmill. However, sex had a substantial impact with females exhibiting better values. Practitioners should employ at least two separate trials within a session, in addition to multiple familiarization sessions, to achieve reliable non-motorized treadmill sprint performances

Impact of a 5-week individualised training program on physical performance and measures associated with musculoskeletal injury risk in army personnel: A pilot study

Objective: To examine the feasibility and effect of an individualised and force-plate guided training program on physical performance and musculoskeletal injury risk factors in army personnel. Design: Pre-post, randomised control. Methods: Fourteen male and five female Australian Army soldiers were randomised into two groups and performed 5-weeks of physical training. The control group (n = 9) completed standard, group-designed, physical training whilst the experimental group (n = 8) completed an individualised training program. Physical (push-ups, multi-stage fitness test, three repetition maximum (3RM) for squat, strict press, deadlift and floor press), occupational (weight-loaded march time), and technological assessments (two-leg and one-leg countermovement jumps (CMJ), one-leg balance, one-arm plank) were conducted prior to and following the training period. Comparisons between groups and changes within groups were conducted via Mann–Whitney U tests. Results: Compared to the control group, the experimental group exhibited a significantly smaller improvement for weight-loaded march time (−0.7% ± 4.0% vs. −5.1% ± 3.0%, p = 0.03) and a greater improvement for deadlift-3RM (20.6% ± 11.9% vs. 8.4% ± 6.8%, p = 0.056). All other outcomes were similar between groups. Visually favourable alterations in the two-leg CMJ profile with no reports of injuries were noted for the experimental group. Conclusions: Individualised physical training was feasible within an army setting and, for the most part, produced similar physical, occupational and technological performances to that of standard, group-designed physical training. These preliminary results provide a foundation for future research to expand upon and clarify the benefits of individualised training programs on long-term physical performance and injury risk/incidence in active combat army personnel

Reliability of Force Plate Metrics During Standard Jump, Balance, and Plank Assessments in Military Personnel

Introduction: Prevention of musculoskeletal injury is vital to the readiness, performance, and health of military personnel with the use of specialized systems (e.g., force plates) to assess risk and/or physical performance of interest. This study aimed to identify the reliability of one specialized system during standard assessments in military personnel. Methods: Sixty-two male and ten female Australian Army soldiers performed a two-leg countermovement jump (CMJ), one-leg CMJ, one-leg balance, and one-arm plank assessments using a Sparta Science force plate system across three testing sessions. Sparta Science (e.g., total Sparta, balance and plank scores, jump height, and injury risk) and biomechanical (e.g., average eccentric rate of contraction, average concentric force, and sway velocity) variables were recorded for all sessions. Mean ± SD, intraclass correlation coefficients (ICCs), coefficient of variation, and bias and limits of agreement were calculated for all variables. Results: Mean results were similar between sessions 2 and 3 (P > .05). The relative reliability for the Sparta Science (ICC = 0.28-0.91) and biomechanical variables (ICC = 0.03-0.85) was poor to excellent. The mean absolute reliability (coefficient of variation) for Sparta Science variables was similar to or lower than that of the biomechanical variables during the CMJ (1-10% vs. 3-7%), one-leg balance (4-6% vs. 9-14%), and one-arm plank (5-7% vs. 12-17%) assessments. The mean bias for most variables was small (<5% of the mean), while the limits of agreement varied with most unacceptable (±6-87% of the mean). Conclusions: The reliability of most Sparta Science and biomechanical variables during standard assessments was moderate to good. The typical variability in metrics documented will assist practitioners with the use of emerging technology to monitor and assess injury risk and/or training interventions in military personnel

Cardiac autonomic and salivary responses to a repeated training bout in elite swimmers

This study examined the acute training responses of heart rate variability (HRV) and salivary biomarkers (immunoglobulin A and alpha-amylase) following a standardised training bout in Paralympic swimmers. Changes in HRV, sIgA and sAA were documented Monday morning, Monday afternoon and Tuesday morning over a 14-week monitoring period leading into international competition. Magnitude based inferences with effect sizes (ES) were used to assess the practical significance of changes each week. Normal training responses elicited increases in HR, 1, sAA and sIgA, accompanied by decreases in HF(nu), standard deviation of instantaneous RR variability (SD1) and the root mean square of successive differences (RMSSD) from Monday morning to Monday afternoon, and to Tuesday morning with similar week to week responses for most variables. Changes in RMSSD from Monday a.m. to p.m. were likely smaller (less negative) for Week 7 (78/18/3, ES = 0.40) following a competition weekend with similar changes observed from Monday a.m. to Tuesday a.m. (90/5/5, ES = 1.30). In contrast, the change in sAA from Monday a.m. to p.m. was very likely less (more negative) at Week 7 (0/0/99, ES = -2.46), with similar changes observed from Monday a.m. to Tuesday a.m. (0/0/99, ES = -4.69). During the taper period, there were also likely increases in parasympathetic modulations (RMSSD, Weeks 12-14) along with increased immune function (sIgA, Week 13) that demonstrated a favourable state of athlete preparedness. Used together, HRV and sAA provide coaches with valuable information regarding physiological changes in response to training and competition

Team performance indicators explain outcome during women's basketball matches at the Olympic games

The Olympic Games is the pinnacle international sporting competition with team sport coaches interested in key performance indicators to assist the development of match strategies for success. This study examined the relationship between team performance indicators and match outcome during the women's basketball tournament at the Olympic Games. Team performance indicators were collated from all women's basketball matches during the 2004-2016 Olympic Games (n = 156) and analyzed via linear (binary logistic regression) and non-linear (conditional interference (CI) classification tree) statistical techniques. The most parsimonious linear model retained "defensive rebounds", "field-goal percentage", "offensive rebounds", "fouls", "steals", and "turnovers" with a classification accuracy of 85.6%. The CI classification tree retained four performance indicators with a classification accuracy of 86.2%. The combination of "field-goal percentage", "defensive rebounds", "steals", and "turnovers" provided the greatest probability of winning (91.1%), while a combination of "field-goal percentage", "steals", and "turnovers" provided the greatest probability of losing (96.7%). Shooting proficiency and defensive actions were identified as key team performance indicators for Olympic female basketball success. The development of key defensive strategies and/or the selection of athletes highly proficient in defensive actions may strengthen Olympic match success. Incorporation of non-linear analyses may provide teams with superior/practical approaches for elite sporting success