Models to predict injury, physical fitness failure and attrition in recruit training: a retrospective cohort study.

Attrition rate was similar between 28-day and 80-day courses. In comparison to the 80-day full course, the 28-day course had a lower rate of injury but a higher number of injuries per person-year and of fitness test failure. These findings suggest fitness level at the commencement of training is a critically important factor to consider when designing the course curriculum, particularly short courses.