INTRODUCTION: It is important for military commanders to know the extent of fatigue experienced by soldiers undergoing a long-term military training. This knowledge can enable them to determine the level of physical capabilities of soldiers. The present study aimed to evaluate changes in the level of chosen biochemical parameters in blood during the survival training of Polish Naval Academy cadets. METHODS: Participating voluntarily in the research study were 14 cadets. All subjects were men, ages 23.1 2.0 yr. During the 36-h survival training, the subjects were deprived of sleep. The following biochemical parameters were assessed in venous blood collected from the cadets: creatine kinase (CK) activity, concentration of lipid hydroperoxides (LOOHs), superoxide dismutase activity (SOD), and glutathione peroxidase activity (GPx). RESULTS: After 36 h of training a significant increase was observed in CK (from 183.1 up to 530.2 U L¹), LOOHs (from 1.72 up to 3.74 mol L¹), and GPx (from 27.4 up to 36.4 U gHb¹). After 12 h of rest, the level of LOOHs returned to the initial level, GPx activity did not change significantly, and CK activity was significantly higher than those at baseline (422.3 U L¹). DISCUSSION: The 36-h survival training increased oxidative stress, which contributed to the damage to muscle cells in the group of cadets of the Polish Naval Academy. The intensity of postexercise changes in the level of oxidative damage indicators is dependent on the initial level of enzymatic antioxidant defense. The 12-h recovery proved to be too short to regenerate the damaged muscle tissue. Tomczak A, Jówko E, Różański P. Survival training effects on oxidative stress and muscle damage biomarkers of naval cadets. Aerosp Med Hum Perform. 2020; 91(9):720724.