effects of hypoxic and normoxic training in altitude on hif-1α and pgc-1α levels in elite endurance runners

Introduction: training at altitude or in a hypoxic environment has gained attention among athletes, coaches, and scientists to enhance sea-level performance. however, the efficacy of “living-low, training-high, training-low” (llthtl) strategy to escalate the mechanisms associated with enhancing performance in the human athletes is still unknown. the present study aimed to investigate the effect of the llthtl on hypoxia-inducible factor-1 alpha (hif-1α) and peroxisome proliferator-activated receptor-gamma coactivator-1alpha (pgc-1α) levels in elite endurance runners. methods: the study has a crossover design in university laboratory. eight elite male runners (mean±sd age: 24.50±3.96 years; mean±sd height: 179.75±4.62 cm; mean±sd body mass: 67.37±3.42 kg; mean±sd body mass index: 20.85±1.11 kg/m²) took part in the research. after 4 weeks of living-low (ll), the athletes performed 4 weeks training-high (th) and then, 3 weeks training-low (tl). main outcome measures: anthropometric parameters, 1500m running performance (1500 m), pgc-1α, and hif-1α levels were measured in four different time points: pre-ll, post-ll, post-th, and post-tl. results: there were no significant differences between the 4 time points for body mass and body mass index (p>0.05). the 1500m running performance was improved significantly (p<0.001) at post-th as well as post-tl compared with the pre-ll and post-ll. th decreased hif-1α level but did not affect pgc-1α. besides, tl increased both hif-1α and pgc-1α. conclusion: training at altitude reduces hif-1α and training at sea-level increased pgc-1α and hif-1α levels. both types of training induced an improvement in the 1500m running performance . athletes and coaches seek advice on the effective training strategy to enhance performance at different altitudes.