Stress hormonal factors, fatigue, and antioxidant responses to prolonged speed driving.

Oxygen free radicals have been implicated in exercise-induced cell and tissue injury, indicating an oxidative stress. Fatigue accompanied by a number of physiological and metabolic changes is in indication of overtraining. This study aimed to examine the influence of a continuous 24-h intermittent speed driving (1 h driving/1 h stop), on the response of hormones, antioxidative factors, lipid, and enzyme levels. Seven race car drivers of national level were examined before, during, and immediately after the trial of speed driving on a test designed to check endurance to stress. The parameters measured were: testosterone (Tes), cortisol (Cor), IgM, IgA, cholesterol, HDL, billirubin, ceruloplasmin, urea, uric acid, creatine kinase, and transaminases. Stress hormone Cor declined significantly (p < 0.05), while Tes did not change significantly. Fatigue enzyme, aspartate transaminase (GOT) increased significantly (p < 0.05), while alanine transaminase (GPT) did not change and urea declined. Muscle enzyme, creatine kinase (CK) increased to sixfold (p < 0.01). IgA, IgM and lipids did not change. The primary antioxidant ceruloplasmin increased significantly (p < 0.001), while antioxidants uric acid and glucose remained unchanged. Among the factors measured, ceruloplasmin, cortisol, urea, GOT, and CK seem to give a picture of the organism's alertness and defence capabilities in conditions of stress and fatigue.