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 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.

The doubly labeled water method was used to estimate the energy expended by four members of an Australian Army platoon (34 soldiers) engaged in training for jungle warfare. Each subject received an oral isotope dose sufficient to raise isotope levels by 200-250 (18O) and 100-120 ppm (2H). The experimental period was 7 days. Concurrently, a factorial estimate of the energy expenditure of the platoon was conducted. Also, a food intake-energy balance study was conducted for the platoon. Mean daily energy expenditure by the doubly labeled water method was 4,750 kcal (range 4,152-5,394 kcal). The factorial estimate of mean daily energy expenditure was 4,535 kcal. Because of inherent inaccuracies in the food intake-energy balance technique, we were able to conclude only that energy expenditure, as measured by this method, was greater than the estimated mean daily intake of 4,040 kcal. The doubly labeled water technique was well tolerated, is noninvasive, and appears to be suitable in a wide range of field applications.

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.

The effect of combat ration pack (CRP) feeding on military performance in a tropical environment was assessed. Three groups received different diets: freshly prepared foods (Fresh group), a Full CRP and a Half CRP during the conduct of a routine training exercise over 12 days. Physical, cognition, immune and nutritional status were recorded. Freshly prepared foods were better consumed than CRP foods. A high rate of CRP item discards resulted in subjects eating insufficient food for their energy and carbohydrate requirements and hence significant weight loss, protein catabolism and immune suppression were observed for the two CRP groups. All subjects experienced poor sleep quality with no effect of dietary treatment. Subjects eating CRP reported greater levels of fatigue and negative emotions than the Fresh group. All subjects had poor folate and vitamin K status, which tended to become worse during the exercise period. Subjects drank insufficient water to prevent dehydration and a high rate of cigarette smoking contributed to poor antioxidant status. Despite these negative effects, cognition and physical fitness were maintained over the course of the exercise. This study aimed to document the effect of medium-term CRP feeding on military performance in a tropical environment. The study was conducted during Exercise Northern Awakening, RAAF Base Scherger. Airfield Defence Guards (ADGs) of the Second Airfield Defence Squadron (2AFDS) were recruited into Group 1 (n=10, Full CRP, 15000 kj/day), Group 2 (n=10, Half-CRP, 7500 kj/day) and Group 3 (n=13, Fresh group, fresh rations, 15000 kj/day). Nutritional requirements were estimated by use of the Ration Expert Advisor Program (REAP™). The nutrition study was conducted during a routine ground defence training exercise over 12 days. Indices of physical fitness, cognition, immunocompetence and nutritional status were recorded. Energy expenditure of selected subjects was measured by the doubly-labelled water method. Activity and sleep quality were recorded by use of wrist Actigraphs™. Dietary intake was recorded. RELEASE LIMITATIONRecorded activity and calculated energy expenditure indicated similar levels of physical activity for the three treatment groups. All subjects experienced a highly disruptive and poor sleep quality with no apparent effect of dietary treatment. There was no change in cognition over the study period and no differences were found between the dietary treatment groups.Conclusions and Recommendations 1. The menu, which was designed by use of REAP™, was found to maintain the nutrition status of subjects in the Fresh group.• Further work to tailor REAP™ to Australian conditions is warranted.2. Freshly prepared foods were better consumed than CRP foods. A high rate of ration item discards by ADGs being fed CRP as their sole nutrition resulted in these subjects eating insufficient food for their energy and carbohydrate needs.• Future CRP acceptability studies should focus on understanding the reasons why soldiers discard up to one quarter of the ...