Effects of antioxidant supplementation on exercise performance in acute normobaric hypoxia.

Background/objectives: To compare the effects of a 3-week supplementation between two different mixtures of antioxidants and placebo on aerobic exercise performance in acute normobaric hypoxia.

Subjects/methods: Seventeen subjects were randomly assigned in a double-blind fashion to receive a broad-based antioxidants supplement containing beta-carotene, ascorbic acid, d-alpha-tocopherol-succinate, N-acetylcysteine, riboflavin, zinc, and selenium (antioxidant capsule group [AO group]), or a combination of alpha-ketoglutaric acid (α-KG) and 5-hydroxymethylfurfural (5-HMF; CYL concentrate supplementation group [CS group]), or placebo (PL group). Before and after supplementation, subjects performed two incremental cycle-exercise tests until exhaustion.