Bliss, M. V., Seo, Y., & Glickman, E. L. (2014). Aerobic fitness does not affect blood lactate and carbohydrate metabolism during exercise in hypoxia. Medicine & Science in Sports & Exercise, 46(5), Supplement abstract number 1571.

This study determined if aerobic fitness affected blood lactate, rating of perceived exertion, and grams of carbohydrate utilization during exercise in hypoxia and normoxia. College males (N = 6) participated in two trials consisting of normobaric normoxia (20.93% O2) and normobaric hypoxia (12% O2). Fit (N = 3; VO2max = 51.5 ± 3.1 ml/kg/min) and Unfit (N = 3; VO2max = 34.4 ± 5.6 ml/kg/min) cycled at 50% of their altitude-adjusted VO2max (-26% of normoxia VO2max) for one hour after a two-hour baseline ride.

Blood lactate was significantly higher during exercise in hypoxia compared to normoxia in all Ss and did not differ between groups. Rating of perceived exertion was shown to increase as exercise progressed during both conditions but did not differ between groups. Carbohydrate utilization was not significantly different between groups. However, an interaction effect revealed that Ss used significantly less carbohydrate as exercise progressed during hypoxia versus normoxia.

Implication. Although significant differences in blood lactate and carbohydrate use were revealed in all Ss during exercise in hypoxia compared to normoxia, there were no significant differences between fit and unfit groups with regards to lactate production, rating of perceived exertion, and carbohydrate utilization during exercise in hypoxia.

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