Responses to altitude training in terms of hematological parameters and performance in elite endurance runners

BACKGROUND: The present study aims to investigate the effect of living and training at altitude on the serum levels of HIF-1 alpha, PGC-1 alpha and EPO on the one hand and the performance of 3000-meter long-distance (endurance) runners of Iran's national team on the other. METHODS: After four weeks of training and assessment at sea level, 32 long-distance male runners were divided randomly into four equal groups for living and training at altitude (1500-meter, 2000-meter, 2350-meter, and 2500-meter). All the runners performed the same training programs. Blood samples were taken at sea level in order to assess the changes of HIF-1 alpha, PGC-1 alpha and EPO serum levels and 3000-meter running performance before and after the altitude training period. Repeated measures variance analysis method at the significance level P <= 0.05 was utilized to assess the data. RESULTS: The 3000-meter run showed a significant improvement (P <= 0.05) from before and to after training at altitudes (1500-meter, 2000-meter and 2350-meter); however, the given changes were not significant at altitude 2500 m (P >= 0.05). In addition, significant changes in HIF-1 alpha level were not observed (P >= 0.05). It should be noted that significant changes occurred in PGC-1 alpha and EPO levels from before and to after life and training at altitude (P <= 0.05). CONCLUSIONS: Generally, it seems that specific training programs at altitude bring about changes in cellular metabolism and increase the level of PGC-1 alpha and EPO through HIF-1 alpha-independent mechanisms at the time of training. Accordingly, 3000-meter running time can be decreased at lower altitudes.