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 an 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. (C) 1998 Elsevier Science Inc

STRESS-ADAPTATION IN ATHLETES - RELATION OF LIPOPROTEIN LEVELS TO HORMONAL RESPONSE

Increased physical stress is produced in acute exercise conditions before and during a physical trial. The effects of the physical stress on lipid and lipoprotein parameters as well as on testosterone and cortisol levels were examined in male elite athletes. In a sample of 22 measured athletes, 11 showed increases and 11 showed decreases in testosterone levels. Subsequently these subjects were treated as two separate groups for statistical purposes in order to characterise the source of individual differences in response to a stressor. Group 1 showed a 16.1% significant increase in testosterone levels, 13.3% in total cholesterol and low density lipoproteins, and a 105% increase in testosterone/cortisol ratio immediately after an acute bout of physical stress of 30 s. Group 2 showed a -25.8% significant decline in testosterone levels and no significant change in either total cholesterol or lipoprotein concentrations, followed by a significant correlation of all lipid and hormonal parameters to psychophysiological factors, such as skin temperature. A measurement of testosterone/cortisol and total cholesterol and high density lipoprotein (HDL-C) levels after a bout of acute physical stress may give a picture of the ability to ‘’respond quickly” to stress, which will be useful in assessing the performance of the elite athlete

COLD SWIMMING STRESS - EFFECTS ON SERUM-LIPIDS, LIPOPROTEINS AND LCAT ACTIVITY IN MALE AND FEMALE RATS

Effects of consistent cold swimming stress on lipid and lipoprotein metabolism parameters were studied using male and female rats over a period of 60 and 20 days respectively. At the end of treatment serum total cholesterol, high density lipoproteins (HDL-C) and lecithin:cholesterol acetyltransferase (LCAT) activity declined in both male and female rats. TC/HDL-C ratio declined in 20 days in females, while in males it did not change. Free fatty acids increased, while triglycerides remained unchanged in both sexes. %Lipoprotein distribution in male animals did not show any phenotype alteration except in the group of 40 days where %VLDL declined and %LDL-C increased. Body weights did not change, except in males in 60 days. Consistent cold swimming stress by lowering HDL-C and LCAT activity seems to influence lipoprotein metabolism