Effect of different intensities of aerobic exercise on urinary excretion of sodium, potassium and urea in hypoxia and normoxia conditions in young soccer players

Environment conditions such as altitude affected on urinary system, however the effect of exercise intensity in hypoxia condition on urinary system is not well known. Thus the aim of present study was to examine the urinary excretion of sodium, potassium and urea in response to different intensities of aerobic exercise in hypoxia and normoxia conditions in young soccer players. 

 Ten young soccer players (age: 18.2 ± 0.5; Height 174.2 ± 4.1 cm; Weight: 64.4 ± 3.6 kg; BMI: 21.2 ± 2.1 kg/m2 mean ± SD) were participated in this study as the subject. They performed 30 min aerobic training with 55, 70 and 85% of their maximum heart rate on treadmill in normoxia condition. After 48h, the same exercises were performed in hypoxia (2500 meters higher than the sea level) condition. Before and 20 min after the each exercise, urinary sample was collected to evaluate urinary excretion of sodium, potassium and urea. 

 The results indicated that sodium excretion were increased as well as exercise intensity increased in hypoxia and normoxia conditions (p < 0.05). Results demonstrated that after high intensity exercise in hypoxia and normoxia conditions and after moderate intensity exercise in hypoxia condition, potassium excretion were decreased significantly (p < 0.05). For urea excretion, no significant differences were observed after different exercise intensities in hypoxia or normoxia condition. 

 Generally, it seems that sodium excretion increased and potassium excretion decreased as well as exercise intensity increased in hypoxia and normoxia conditions and this predominate in hypoxia condition. Therefore, this is very important to electrolyte balance maintaining during high intensity exercise in hypoxia condition.