Beyond change scores: Employing an improved statistical approach to analyze the impact of entry fitness on physical performance during British Army basic training in men and women.

The aim was to use a robust statistical approach to examine whether physical fitness at entry influences performance changes between men and women undertaking British Army basic training (BT). Performance of 2 km run, seated medicine ball throw (MBT) and isometric mid-thigh pull (MTP) were assessed at entry and completion of Standard Entry (SE), Junior Entry-Short (JE-Short), and Junior Entry-Long (JE-Long) training for 2350 (272 women) recruits. Performance change was analyzed with entry performance as a covariate (ANCOVA), with an additional interaction term allowing different slopes for courses and genders (p < 0.05). Overall, BT courses saw average improvements in 2 km run performance (SE: -6.8% [-0.62 min], JE-Short: -4.6% [-0.43 min], JE-Long: -7.7% [-0.70 min]; all p < 0.001) and MBT (1.0-8.8% [0.04-0.34 m]; all p < 0.05) and MTP (4.5-26.9% [6.5-28.8 kg]; all p < 0.001). Regression models indicate an expected form of "regression to the mean" whereby test performance change was negatively associated with entry fitness in each course (those with low baseline fitness exhibit larger training improvements; all interaction effects: p < 0.001, η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ > 0.006), particularly for women. However, when matched for entry fitness, men displayed considerable improvements in all tests, relative to women. Training courses were effective in developing recruit physical fitness, whereby the level of improvement is, in large part, dependent on entry fitness. Factors including age, physical maturity, course length, and physical training, could also contribute to the variability in training response between genders and should be considered when analyzing and/or developing physical fitness in these cohorts for future success of military job-task performance.

Association between external training loads and injury incidence during 44 weeks of military training.

Military training is physically arduous and associated with high injury incidence. Unlike in high-performance sport, the interaction between training load and injury has not been extensively researched in military personnel. Sixty-three (43 men, 20 women; age 24 ± 2 years; stature 1.76 ± 0.09 m; body mass 79.1 ± 10.8 kg) British Army Officer Cadets undergoing 44 weeks of training at the Royal Military Academy Sandhurst volunteered to participate. Weekly training load (cumulative 7-day moderate-vigorous physical activity [MVPA], vigorous PA [VPA], and the ratio between MVPA and sedentary-light PA [SLPA; MVPA:SLPA]) was monitored using a wrist-worn accelerometer (GENEActiv, UK). Self-report injury data were collected and combined with musculoskeletal injuries recorded at the Academy medical center. Training loads were divided into quartiles with the lowest load group used as the reference to enable comparisons using odds ratios (OR) and 95% confidence intervals (95% CI). Overall injury incidence was 60% with the most common injury sites being the ankle (22%) and knee (18%). High (load; OR; 95% CI [>2327 mins; 3.44; 1.80-6.56]) weekly cumulative MVPA exposure significantly increased odds of injury. Similarly, likelihood of injury significantly increased when exposed to low-moderate (0.42-0.47; 2.45 [1.19-5.04]), high-moderate (0.48-0.51; 2.48 [1.21-5.10]), and high MVPA:SLPA loads (>0.51; 3.60 [1.80-7.21]). High MVPA and high-moderate MVPA:SLPA increased odds of injury by ~2.0 to 3.5 fold, suggesting that the ratio of workload to recovery is important for mitigating injury occurrence.

Relationship Between Performance Competence and Cardiorespiratory Fitness in Contemporary Dance.

AIMS: While a foundation of basic cardiorespiratory fitness is beneficial for coping with the physiological demands of dance training and performance, the extent to which cardiorespiratory fitness levels are related to performance ability is not all-together clear. This study aimed to directly compare aerobic capacity (VO2peak) and anaerobic threshold (AT) to an aesthetic competence measure (ACM) in student contemporary dancers. METHODS: Participants were 18 contemporary dance students and all undertook a one-off treadmill test to volitional exhaustion in the week leading up to a performance to determine VO2peak and AT. In the same week, a final rehearsal for the performance was filmed to allow retrospective analysis of specific performance competence. RESULTS: Mean VO2peak values of 47.67 ± 5.84 ml/kg/min and AT values of 43.18 ± 7.72 ml/kg/min (90.68 ± 11.87 %VO2peak) were recorded, and the mean total ACM score was 52.67 ± 8.74. No significant correlations were found between cardiorespiratory fitness variables and ACM scores. Regression analyses revealed experience level to be the only significant predictor of total ACM score (p<0.05, R2=0.12, SEE=11.91). CONCLUSIONS: The range of choreography used for assessment may limit the present study; nevertheless, as level of experience did significantly predict ACM total score, it is suggested that vocational dance training may be developing the performance and technical skills of students but not sufficiently developing their physical conditioning.

Validity of energy expenditure estimation methods during 10 days of military training.

Wearable physical activity (PA) monitors have improved the ability to estimate free-living total energy expenditure (TEE) but their application during arduous military training alongside more well-established research methods has not been widely documented. This study aimed to assess the validity of two wrist-worn activity monitors and a PA log against doubly labeled water (DLW) during British Army Officer Cadet (OC) training. For 10 days of training, twenty (10 male and 10 female) OCs (mean ± SD: age 23 ± 2 years, height 1.74 ± 0.09 m, body mass 77.0 ± 9.3 kg) wore one research-grade accelerometer (GENEActiv, Cambridge, UK) on the dominant wrist, wore one commercially available monitor (Fitbit SURGE, USA) on the non-dominant wrist, and completed a self-report PA log. Immediately prior to this 10-day period, participants consumed a bolus of DLW and provided daily urine samples, which were analyzed by mass spectrometry to determine TEE. Bivariate correlations and limits of agreement (LoA) were employed to compare TEE from each estimation method to DLW. Average daily TEE from DLW was 4112 ± 652 kcal·day-1 against which the GENEActiv showed near identical average TEE (mean bias ± LoA: -15 ± 851 kcal. day-1 ) while Fitbit tended to underestimate (-656 ± 683 kcal·day-1 ) and the PA log substantially overestimate (+1946 ± 1637 kcal·day-1 ). Wearable physical activity monitors provide a cheaper and more practical method for estimating free-living TEE than DLW in military settings. The GENEActiv accelerometer demonstrated good validity for assessing daily TEE and would appear suitable for use in large-scale, longitudinal military studies.

Factors Affecting Performance on an Army Urban Operation Casualty Evacuation for Male and Female Soldiers.

INTRODUCTION: This study was conducted to determine what physical and physiological characteristics contribute to the performance of an urban operation casualty evacuation (UO) and its predictive test, FORCE combat (FC) and describe the metabolic demand of the UO in female soldiers. METHODS: Seventeen military members (9 M and 8 F) completed a loaded walking maximal aerobic test, the UO and FC. Heart rate reserve (HRR) and completion time were used as efficiency/performance measures. Oxygen consumption (VO2) was directly measured for UO on five female participants with a portable indirect calorimetry system, and analyzed using descriptive statistics. Stepwise multiple regression analysis was used to determine the contribution of the non-modifiable (age, sex, height) and modifiable characteristics (lean body mass to dead mass ratio (LBM:DM), VO2max corrected for load (L.VO2max), peak force (PF) measured on an isometric mid-thigh pull (IMTP) and medicine ball chest throw distance (Dist) on to the performance of each exercise. RESULTS: LBM:DM and PF were the only factors included in the stepwise regression model for UO, predicting 70% of UO performance (p < 0.01). For FC, L.VO2max only was included in the stepwise regression model predicting 54% of FC performance (p < 0.01). Sex, age and height were not included in the regression model. The average metabolic cost of UO was 21.4 mL of O2*kg-1*min-1 in female soldiers while wearing PPE. CONCLUSION: This study showed that modifiable factors such as body composition, PF on IMTP and L.VO2max are key contributors to performance on UO and FC performance.