Abstract

The aim of this study was to investigate the effect of graded maximal aerobic exercise on some metabolic hormones, muscle damage and some metabolic end products in professional sportsmen. Twelve young professional football players participated in the study. Subjects performed shuttle run test. Blood samples were collected before, immediately after and one hour after the single exercise. The levels of testosterone (T) and cortisol (C) as metabolic hormones; creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate amino transferase (AST) as muscle damage markers; urea and uric acid levels, as metabolic end products, were determined. Testosterone levels significantly increased immediately after exercise (p = 0.027), but increase in the cortisol levels was not significant. However, cortisol levels demonstrated a significant difference between immediately after and one hour after exercising (p = 0.006). Both testosterone and cortisol levels decreased to their initial levels one hour after exercising. Although changes in the urea levels were not significant (p = 0.667), increase in the uric acid level one hour after the exercising was significant (p = 0.005). While the increase in CK activity was significant (p = 0.023), changes in AST (p = 0.170) and LDH levels were not significant (p = 0.139). Besides constituting an anabolic effect, graded maximal aerobic load also caused an increase in cortisol and uric acid in professional football players. Due to being accustomed to these types of exercises, subjects had inconsiderable muscle damage after loading. The exercise caused an increase in serum uric acid due to renal clearance decrease and increasing endogenous purines with contribute protein degradation.

Key words: Exercise, testosterone, creatine kinase, urea, uric acid.