ACUTE EFFECTS OF EXERCISE AT LOW-ALTITUDE (350 METERS BELOW SEA-LEVEL) ON HORMONES OF THE ANTERIOR-PITUITARY AND CORTISOL IN ATHLETES

The purpose of this study was to examine the effects of exercise on an terior pituitary hormones (adrenocorticotropic hormone (ACTH), leutini zing hormone (LH) and growth hormone) as well as on cortisol at low al titude (350 meters below the sea level) and to compare these effects w ith those at a moderate level altitude (620 meters above the sea level ). Ten male athletes with running experience participated in a 21-Km c ompetitive race. Serum levels of ACTH, LH, growth hormone and cortisol were measured before and after the race at each of the altitudes. A s ignificant increase in the serum levels of ACTH and growth hormone wer e observed in response to this exercise at low altitude. Similar exerc ise at 620 meters above the sea level resulted in a significant increa se only in the serum levels of growth hormone. Serum levels of LH were not affected by this kind of exercise at both altitudes. Serum cortis ol levels were increased following exercise at both altitudes. Altoget her, these observations show a differential response of the anterior p ituitary to exercise at low and normal altitudes. These data suggest t hat ACTH may have a role in the acclimatization to exercise at low alt itudes. The role of growth hormone and LH in this conditioning process seems to be insignificant. The changes in serum cortisol levels in re sponse to exercise at both altitudes correlate well with the effect of exercise on energy metabolism.