Association Between Ambulatory Physical Activity and Injuries During United States Army Basic Combat Training

Background: Associations between physical activity and injuries have been previously examined using self-reports. The present investigation examined this association using objective measures of activity and injury. Methods: To quantify ambulatory activity, pedometers were worn daily by recruits in 10 Army Basic Combat Training companies during the 9-week training cycle. Injuries were obtained from a medical surveillance system, defined as traumatic or overuse events resulting in a medical care provider visit. A daily questionnaire documented whether or not recruits wore the pedometers and trained with their companies for the entire day. Results: Training companies were categorized by activity level into 3 groups with higher activity (HA, 17,948 ± 550 steps/day), 4 with moderate activity (MA, 16,346 ± 768 steps/day) and 3 with lower activity (LA, 14,772 ± 400 steps/day). Among men, the MA and HA groups were at 1.52 (95% confidence interval [95% CI] = 1.15−2.01) and 1.94 (95% CI = 1.46−2.61) times higher in...