Increased Environmental Oxygen Availability Boosts Cycling Performance
Every athlete knows that endurance performance decreases at high altitude, where there is less oxygen available to the working muscles. But is the inverse also true? Does increasing the availability of atmospheric oxygen enhance exercise performance?
Researchers from the University of Cape Town, South Africa, recently sought to answer this question. Eleven male subjects completed two simulated 20K cycling time trials: one in normal atmospheric conditions and one in an oxygen-enriched environment. On average, the subjects performed 5% better in the oxygen-enriched trial than in the other trial. Interestingly, power output tend to decrease in the latter portion of the normal oxygen trial (except in the final stretch), but it held steady throughout the oxygen-enriched trial (also increasing at the very end). Percevied exertion was equal in both trials, meaning subjects felt they were working equally hard in both trials, even though they were actually working harder in the oxygen-enriched trial.
The authors of the study concluded, "This suggests that improved exercise performance in hyperoxia may be the result of increased muscle activation leading to greater power outputs. The finding of identical RPE, lactate and heart rate in both trials suggests that pacing strategies are altered to keep the actual and perceived exercise stress at a similar level between conditions. We suggest that a complex, intelligent system regulates exercise performance through the control of muscle activation levels in an integrative manner under conditions of normoxia and hyperoxia." |
