Norwegian military field exercises in the arctic: endocrine and metabolic responses

This study examined select endocrine and metabolic responses of Norwegian soldiers to performing military physical training in an arctic field setting which involved cold exposure. Also, the impact on nocturnal shelter conditions on the physiological responses was investigated. A field based group (EXP, n = 17) lived in tents and a garrison group (CON, n = 16) lived in barracks for 10 days while performing similar daily training in cold weather. Cortisol, testosterone, thyroxine, glucose, triglycerides, and beta-hydroxybutyrate were measured on day 1, 5, and 10 of training. The cortisol and testosterone findings suggest a moderate, but somewhat transient, stress response is associated with field living. The living conditions, however, did not seem to influence the metabolic responses to the physical activity. The observed changes in thyroxine, glucose, and triglycerides (i.e., reductions) suggest that an energy imbalance may accompany military training in the arctic.