Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5923961 | Physiology & Behavior | 2015 | 7 Pages |
â¢Little is known about how exercise under hypoxia alters cognitive function.â¢We examined the combined effects of moderate hypoxia and prolonged exercise.â¢Heart rate was matched during exercise between normoxia and moderate hypoxia.â¢Moderate hypoxia did not impair working memory and executive function.â¢Cognitive function improved during prolonged exercise under moderate hypoxia.
It has been suggested that acute exercise improves cognitive function. However, little is known about how exercise under hypoxia affects cognitive function. The purpose of this study was to determine if hypoxia alters working memory and executive function during prolonged exercise. Sixteen participants performed cognitive tasks at rest and during exercise under normoxia and hypoxia [fraction of inspired oxygen (FIO2)Â =Â 0.15, corresponding to an altitude of approximately 2600Â m]. The level of hypoxia was moderate. We used a combination of Spatial Delayed Response (Spatial DR) task and Go/No-Go (GNG) task, where spatial working memory and executive function are required. Working memory was assessed by the accuracy of the Spatial DR task, and executive function was assessed by the accuracy and reaction time in the GNG task. The participants cycled an ergometer for 30Â min under normoxia and moderate hypoxia while keeping their heart rate (HR) at 140Â beats/min. They performed the cognitive tasks 5Â min and 23Â min after their HR reached 140Â beats/min. Moderate hypoxia did not alter the accuracy of the Spatial DR (PÂ =Â 0.38) and GNG tasks (PÂ =Â 0.14). In contrast, reaction time in the GNG task significantly decreased during exercise relative to rest under normoxia and moderate hypoxia (PÂ =Â 0.02). These results suggest that moderate hypoxia and resultant biological processes did not provide sufficient stress to impair working memory and executive function during prolonged exercise. The beneficial effects on speed of response appear to persist during prolonged exercise under moderate hypoxia.