Aerobic and anaerobic exercise capacities of elite middle-distance runners after two weeks of training at moderate altitude

The effect of short-term altitude training on sea-level physiological characteristics in elite runners was investigated. Seven middle-distance runners (6 men, 1 woman) belonging to the Swedish national team (mean age 23 years) spent 2 weeks of training at 2000 m above sea level in Kenya. Treadmill tests were performed before and 6 and 12 d after the altitude sojourn. Six other runners (4 men, 2 women) had a corresponding training sojourn at sea level in Portugal (control group). Ro of the runners (1 man, 1 woman) in the Kenya group were omitted from the study because of gastroenteritis. The maximal oxygen uptake (VO_{2 max}; pretravel: Kenya group 212 and control group 188 ml · kg^−0.75 - min⁻¹), maximal treadmill time and oxygen cost of running were unchanged in both groups. The maximal oxygen deficit increased in all subjects after the Kenya sojourn (mean 19±6%). Heart rates during running at specified submaximal running velocities were lower post-altitude (Kenya group), but tended to be higher after sea-level training (control group). Maximal heart rate was unchanged in both groups. Perceived exertion (Borg) during submaximal running was lower post-altitude. Submaximal and maximal blood lactate and plasma catecholamine concentrations were not altered in any of the groups. Post-exhaustive plasma ammonia levels were decreased 12 d after altitude descent in the Kenya group. The results suggest an unchanged aerobic capacity in elite middle-distance runners after short-term training at moderate altitude. However, a change in the circulatory regulation during submaximal exercise was observed. Furthermore, anaerobic capacity improved but this bore no clear relation to lactate or ammonia metabolism.