2111 Past anecdotal reports suggested that injury incidence increased immediately following foot marches (FM) in US Army Basic Combat Training (BCT). To mitigate injuries, the Army instituted a progressive foot marching schedule; recruits begin with a 3 km foot march and progressively increase the distance on 5 subsequent marches until they complete a 15 km foot march by the end of BCT. PURPOSE: To determine if injury incidence increases following foot marches in BCT. METHODS: Participants were 930 men and 622 women in BCT. As part of standard protocol, trainees completed foot marches at a pace of about 4.8 km/h in military uniform and while carrying a load (equipment and rucksack) of about 20 kg. The third (FM3) and fourth (FM4) foot marches (8 and 10 km, respectively) were selected for review since the last 2 foot marches were associated with a very physically demanding field exercise. Injuries were obtained from a medical surveillance system that captured trainees' visits to the medical treatment clinic. The McNemar test for related samples was used to examine the distribution of injuries before and after the march. RESULTS: Among women, injury incidence was higher in the 3 days prior to FM3 (before = 4.0 injured/100 trainees, after = 1.3 injured/100 trainees, p<0.01) but injury incidence before and after FM4 was similar (before = 4.0 injured/100 trainees after = 3.9 injured/100 trainees, p = 1.00). There was no significant difference in pre- and post-FM injury incidence among men for FM3 (before = 1.7 injuries/100 trainees, after = 1.3 injuries/100 trainees, p = 0.56) or FM4 (before = 2.4 injuries/100 trainees, after = 1.6 injuries/100 trainees, p = 0.30). Examination of training schedules suggested that injury incidence prior to FM4 may have been confounded by participation in the confidence course and rappelling tower. CONCLUSION: With the way BCT is currently structured, FM do not appear to be associated with higher injury incidence in the period immediately following the march. It is dif. cult to isolate the influence of specific BCT events on injuries since trainees perform many physically demanding tasks in close proximity.