Physiologically stressing situations generate responses in metabolic processes that allow organisms to survive and, therefore, produce biomarkers that act as early predictors of physical or cognitive fitness and the capability, or incapability, to adapt. Such markers have been studied in the context of sports in order to monitor training effects. However, there is scarce information describing the response of blood and urinary biomarkers during military occupational activities in tropical environments.
PURPOSE: To describe the impact of a Basic Combat Course (BCC) on some biochemical parameters in Colombian last year military students through values and differences on objective variables that, in high performance sports, are used as indicators of responses and adaptations, and that could indicate the need for liquid or food intake, sleep or rest, in order to minimize the adverse effects of environmental threats.
METHODS: 20 last year military students were evaluated through blood and urine samples taken before and after the last two weeks of a BCC. Blood samples were collected in the morning, before any food intake and any physical activity, in order to process BUN, creatinine, BUN/creatinine, hemoglobin, hematocrit, sodium, potasium, urea and CPK. Urine was recollected throughout a 24 hour period in order to process urinary volume and urinary ureic nitrogen. General conditions included energy deficit (+/− −2709Kcal/day), sleep deprivation (+/− 3.3 hrs/day), and limited water intake (+/− 2862 ml/day). Registered temperatures ranged between 26°C and 39°C with relative humidity between 54% and 100%. Parameters were analyzed by means of a paired student T.
RESULTS: The means for the changes in creatinine, sodium, hemoglobin, hematocrit, CPK and urinary ureic nitrogen were significant (P <0.05). However, it is of great clinical significance the fact that most of the parameters had values within abnormal range before, as well as after, the last two weeks of the course (95% IC): BUN (32.7 +/− 5.2 mg/dl, 35.2 +/− 5.8 mg/dl), BUN/creatinine (37.5 +/− 11.7, 32.5 +/− 6.2), sodium (153 +/− 5 mEq/L, 141 +/−2 mEq/L), hemoglobin (13.4 +/− 0.7 gr/dl, 15 +/− 1.4 gr/dl), hematocrit (39 +/− 1.8%, 44.8 +/− 4.5%), CPK (610 +/− 553 u/L, 246 +/− 119 u/L), urea (11.61 +/1.85mmol/L, 12.5+/−2.06 mmol/L), urinary volume 24 hours (856+/−306 cc, 670 +/− 311 cc) and urinary ureic nitrogen (13.2 +/− 4.4 gr., 7.3 +/− 2.4 gr.).
CONCLUSION: A Basic Combat Course in tropical hot weather has a relevant impact on biochemical parameters that suggest responses to hypo hydration more that adaptations to training.