Running mileage, movement mileage, and fitness in male U.S. Navy recruits

TRANK, T. V., D. H. RYMAN, R. Y. MINAGAWA, D. W. TRONE, and R. A. SHAFFER. Running mileage, movement mileage, and fitness in male U.S. Navy recruits. Med. Sci. Sports Exerc., Vol. 33, No. 6, 2001, pp. 1033–1038. The purpose of this study was to determine whether there is a relationship between overall fitness improvement and varying amounts of running and movement mileage. Subjects were male U.S. Navy recruits (N = 1703, 25 divisions), ages 17–35 yr (mean age = 20.1 ± 2.9 yr), who attended boot camp from April 1996 through August 1996. During the first week of training, recruits performed a 1.5-mile run to determine baseline fitness levels. The results from the initial run were compared with a final 1.5-mile run conducted 6 wk later. Based on an age-adjusted fitness scale for a 1.5-mile run time, about one third of the recruits began recruit training in “Excellent-Superior” condition (N = 558), one third began in “Good” condition (N = 582), and one third began in “Poor-Fair” condition (N = 563). Running mileage among divisions ranged from 11.5 to 43.5 miles for the entire 7-wk training period (mean = 22.7 ± 7.2 miles; 8–22 run days, mean = 13 ± 4 d). In addition to running, the divisions accumulated many movement miles (110–202 miles; mean = 145 ± 26 miles) while marching in formation. Recruits who began training in Poor-Fair condition improved the most with an average decrease in run time of 1:55 ± 1:06 min (15.6% improvement). The Good group improved by 47 ± 37 s (7.3% improvement), and the Excellent-Superior group improved by 17 ± 32 s (2.9% improvement). The magnitude of fitness improvement, as measured by run time improvement, was directly related to baseline fitness level but not related to movement mileage or high-intensity run mileage accrued during training.