ABSTRACT:Background: Diagnosing rhabdomyolysis has usually defined at least five or ten times the upper limit creatine kinase level; but it is conservative for Exertional rhabdomyolysis. The aim was to analysis the biomarkers during a military operation in an extreme environment with high physical demand. Material and Methods: Seventeen male military personnel (age: 27.83 ± 2.96 years; weight: 76.31 ± 7.67 kg; and height 174.92 ± 5.91 cm) participated for this investigation. The creatine kinase (CK); blood urea nitrogen (BUN); creatinine (Cr); sodium (Na); potassium (K); aspartate amino transferase (AST) and alanine amino transferase (ALT) were analyzed. Urine specific gravity (USG) the hydration status was monitored. The Generalized Linear Models for repeated measures and the Friedman’s two-way test were used to comparative moments. Results: The BUN; Cr; Na; and K mean values showed a nonsignificant. The statistical significance of the test was found in CK and AST. There was considerable variability of CK between subjects during the operation. The moderate correlation between CK and Cr was found during study. Conclusion: Elevated CK levels after the operation were characterized as physiological pattern. These results reinforce that CK values are not predictors of renal function in activities with intense and continuous physical demand