ABSTRACT
Water and electrolyte balance are critical for the maintenance of general health. Exercise creates much variation in renal homodynamic and electrolytes excretion. Sauna is also an extreme hot environment placing an individual in heat stress. The aim of this study was to compare the effects of one session aerobic activity and sauna on serum and urinary sodium and potassium concentration in athletes. A quasi-experimental study was conducted on 15 football players of Shahid Beheshti University M.C [Age: 24.5 +/- 2.5 yr; Weight: 72 +/- 8 kg]. Blood samples were taken before and after aerobic activity and sauna, and 24 hours urine was also collected before and after exertion of independent variables. The data were analyzed using mean and standard deviation for statistical description and dependent t-test for inferential analysis. The results showed that one session physical activity significantly increased serum sodium and potassium [p