Effect Of Altitude On Muscle Torque And Proprioception In Elite Alpine Skiers

Abstract

The effects of hypoxia on muscle function remain contentious. Some studies report no modifications, while others have observed a decrease in performance during repeated or sustain muscle contractions attributed to modified neuronal activity. However, none of these studies were specific to athletes competing in high altitude environments, such as Alpine skiers. Currently, it remains unknown how hypoxia influences various muscle performance and injury factors, such as proprioception. PURPOSE: The aim of this study was to determine the effects of hypoxia on proprioception. METHODS: The proprioceptive status of the right knee of 22 elite alpine skiers (26 ±4 yr, 180 ±4 cm, 83 ±7 kg, all members of a national team) was assessed using a threshold to detection of passive movement test (3 flexions and 3 extensions, at 0.2 deg/s,), before and immediately after a fatiguing maximal leg extension test (30 deg/s, 34 repetitions in 150 s), both at sea level (Con, 200m) and at simulated altitude (Alt, 3800m, FiO2 0.13). The conditions were applied in a counterbalanced order and participants were blinded to the conditions. RESULTS: Data showed that acute hypoxia did not significantly affect maximal peak torque (247 ±24 vs. 251 ±25 Nm in Con vs. Alt, p>0.05) or total work (96 ±11 vs. 99 ±9 J in Con vs. Alt, p>0.05) in this group of athletes. Moreover, there was no effect of hypoxia on the movement detection delay, both pre (1.5 ±0.5 vs 1.5 ±0.7 deg in Con vs. Alt) and post (1.7 ±0.7 vs 1.7 ±0.7 deg in Con vs. Alt) the fatiguing task. CONCLUSIONS: These data suggest that proprioception is not affected by hypoxia during a short duration exercise, which replicate the duration of a competitive alpine ski race.