Leila A. Walker

Physical Fitness and Body Composition After a 9-Month Deployment to Afghanistan

PURPOSE To examine change in physical fitness and body composition after a military deployment to Afghanistan. METHODS One hundred and ten infantry soldiers were measured before and after a 9-month deployment to Afghanistan for Operation Enduring Freedom. Measurements included treadmill peak oxygen uptake (peak VO2), lifting strength, medicine ball put, vertical jump, and body composition estimated via dual-energy x-ray absorptiometry (percent body fat, absolute body fat, fat-free mass, bone mineral content, and bone mineral density). RESULTS There were significant decreases (P < 0.01) in peak VO2 (-4.5%), medicine ball put (-4.9%), body mass (-1.9%), and fat-free mass (-3.5%), whereas percent body fat increased from 17.7% to 19.6%. Lifting strength and vertical jump performance did not change predeployment to postdeployment. CONCLUSIONS Nine months deployment to Afghanistan negatively affected aerobic capacity, upper body power, and body composition. The predeployment to postdeployment changes were not large and unlikely to present a major health or fitness concern. If deployments continue to be extended and time between deployments decreased, the effects may be magnified and further study warranted.

Reliability of Military-Relevant Tests Designed to Assess Soldier Readiness for Occupational and Combat-Related Duties

The purpose of this study was to determine the reliability of military-relevant tests designed to assess soldier readiness. Forty-seven soldiers (46 men, 1 woman; 22 +/- 3 years; 80.4 +/- 11.7 kg) performed each of seven soldier readiness tests on four different occasions over the course of 8 weeks. The soldier readiness tests were: (1) 3.2-km load carriage (LC) time-trial, (2) running long jump (RLJ), (3) one-repetition maximum box lift (1RMBL), (4) 10-minute repetitive box lift and carry (RBLC), (5) simulated victim rescue (VR), (6) mock grenade throw (GT) for accuracy, and (7) simulated combat rushes (CR). Repeated measures analysis of variance revealed significant learning effects for 1RMBL, RBLC, and GT; these tests required two (1RMBL and RBLC) or three (GT) trials to obtain statistically stable values. The intraclass correlation coefficient was 0.78 to 0.89 for all tests. LC, 1RMBL, RBLC, CR, and RLJ all demonstrated standard error of measurement values that were 3% to 5%, whereas VR and GT were 9% and 36%, respectively. In conclusion, the 1RMBL, RBLC, and GT tests required familiarization before a stable value was obtained. The LC, 1RMBL, RBLC, CR, and RLJ tests (and, to a lesser degree, the VR test) demonstrated reasonably acceptable levels of reliability and measurement error, whereas the GT test did not.

Effect of Specific Short-Term Physical Training on Fitness Measures in Conditioned Men

Abstract Lester, ME, Sharp, MA, Werling, WC, Walker, LA, Cohen, BS, and Ruediger, TM. Effect of specific short-term physical training on fitness measures in conditioned men. J Strength Cond Res 28(3): 679–688, 2014—Physical training programs that enhance battlefield-related fitness needs have been increasingly advocated as operational demands on the US military have increased, but few studies have evaluated program effectiveness. The purpose of this study was to compare a novel 7-week physical training program with traditional army physical fitness training in improving the selected measures of physical fitness and military task performance. One hundred and eighty subjects performed a 30-m rush wearing a fighting load, a simulated casualty recovery wearing a fighting load, a 1-repetition maximum bench press, a maximum repetition pull-up test, a medicine ball put, a vertical jump, and a T-test agility drill to establish test-retest reliability and normative reference values. One hundred thirty-three subjects were assigned by block randomization to either traditional Army physical training (TT) of calisthenics and running or a novel program (NT) of calisthenics, resistance, aerobic, speed, power, and agility training. The results indicated that between-day reliability was high (intraclass correlation coefficients [ICCs] 3,1; 0.87–0.98) for all measures except for the casualty recovery (ICC 3,1; 0.67). Reliability improved for all the measures that were averaged over 3 trials (ICC 3,3; 0.93–0.95). The NT was superior to TT in improving bench press (8 vs. 3%; p < 0.01), medicine ball put (7 vs. 1%; p < 0.01), 30-m rush times (5 vs. 1%; p < 0.01), and casualty recovery times (17 vs. −15%; p < 0.01). These findings suggest that a short-term physical training program is effective in improving strength, power, and speed among previously conditioned men. Future studies should determine if similar training programs mitigate the injury risk in this population.