Australian army recruits in training display symptoms of overtraining.

The proposition that the demands of recruit training, including physical and psychological stresses, result in symptoms of overtraining was investigated during the 45-day Army Common Recruit Training course. Body mass, physical fitness, fasting blood measures of immune status, hormones (serum free testosterone/cortisol ratio), inflammation, and iron status were measured at baseline and after weeks 5 and 6. Psychological measures of mood and fatigue and general health were measured at the end of each week. Sleep diaries were completed each evening and morning. Evidence for overtraining symptoms of fatigue, sleep disturbance, immune suppression, reduced iron status, high rates of minor injuries, and hormonal changes was found. However, recruits were not pushed so hard that physical performance deteriorated greatly. Accumulated sleep deprivation might be a major contributor to the adverse hormonal changes. We conclude that there was some evidence of recruits being overtrained.

The physiological and psychological effects of combat ration feeding during a 12-day training exercise in the tropics.

The health and psychological effects of combat ration pack (CRP) feeding during 12 days of military training in a tropical environment were investigated. Three groups of air defence guards (ADGs) received either: freshly prepared foods (fresh group, 15 mega joule (MJ), 3,600 kcal, N=13), full CRP (15 MJ, 3,600 kcal, N=10), or one-half CRP (7.5 MJ, 1,800 kcal, N=10). Underconsumption by the full CRP group resulted in CRP groups experiencing similar weight loss, protein catabolism, and immune suppression (both cell-mediated and humoral), whereas the fresh group maintained their weight and protein balance and cell-mediated immune status. CRP groups reported greater fatigue than the fresh group. All ADGs experienced poor sleep quality and declining folate and iron status. ADGs drank insufficient water to prevent dehydration. In the medium term, ADGs were able to adapt to restricted food consumption and poor sleep quality with no decrement in physical fitness or cognition.