Background: Light infantry soldiers (N = 218) completed a 161-km cross-country march over 5 days carrying an average +/- SD load mass (i.e., the weight of all equipment and clothing) of 47 +/- 5 kg.
Methods: Prior to the march, height, weight, body fat, and physical fitness (3.2-km run, sit-ups, push-ups) were measured. Soldiers completed a demographic questionnaire which included questions on age and tobacco use history.
Results: Thirty-six percent (78/218) of the soldiers suffered one or more injuries. Of the total injuries, 48% presented were blisters and 18% were foot pain (not otherwise specified). Eight percent (17/218) of the soldiers were unable to complete the march because of injuries. Thirty-five percent (27/78) of the injured soldiers had 1 or more limited duty days for a total of 69 days. Risk of injury was higher among smokers (risk ratio = 1.8, P = 0.03 compared to nonsmokers) and lower among older soldiers (risk ratio = 3.2, P = 0.02, < 20 years compared to > 24 years).
Conclusions: Carrying heavy loads over long distances can result in a high injury incidence to the lower body, since 36% of soldiers were injured during the 161-km march. Smoking and younger age (< 20 years) were independent risk factors for injuries.