ABSTRACT
The purpose of this study was to investigate the effects of short-term living and training at an altitude of 1, 300 to 1, 800 m on physiological responses of high school elite endurance athletes. Fifteen male and seven female senior high school elite athletes, aged from 15 to 18, from three different sports (cross-country skiing, long-distance running and endurance cycling), participated in our study. The short-term (6 days) altitude exposure did not elicit abnormal responses of body tempera-ture, body weight, blood pressure or urine samples. There were also no significant changes in blood parameters examined before and after altitude exposure. Resting heart rate (HR) increased at altitude and presented an initial peak value followed by a steady decline on the following days of altitude exposure. Blood lactate concentration and exercise peak llR examined by submaximal 20-m shuttle run test decreased after the ascent to altitude and still showed lower values at postaltitude than at prealtitude. We conclude that 6-day living and training at an altitude of 1, 300 to 1, 800 m elicits positive decrements of exercise blood lactate and exercise peak HR as well as adaptive changes of resting IlR for these high school elite endurance athletes, which are probably related to an attenuation of muscle glycogen utilization and alterations in the autonomic neural system taken at altitude.