Antioxidants
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Antioxidants neutralize free radicals; whole-food sources (fruits, vegetables) are beneficial, but high-dose supplements can blunt training adaptations and aren't recommended.
Detail
Antioxidants are compounds that neutralize free radicals — reactive molecules produced by normal metabolism and increased by exercise, pollution, and stress — which in excess cause oxidative stress and cell damage. Dietary antioxidants include vitamin C, vitamin E, carotenoids (beta-carotene), selenium, and a large family of plant polyphenols (in berries, tea, cocoa, colorful produce).
A diet rich in whole-food antioxidant sources — abundant fruits and vegetables — is consistently associated with better health, and this is a core reason such patterns are recommended. However, the once-popular idea that high-dose antioxidant supplements prevent disease has not held up: large trials of isolated antioxidant pills (e.g., high-dose beta-carotene or vitamin E) showed no benefit and some harm.
For athletes there is an additional caveat: exercise-induced free radicals act as signals that trigger adaptation (mitochondrial biogenesis, hypertrophy). Chronically taking high-dose vitamin C and E supplements around training can blunt these adaptations. The practical guidance is to obtain antioxidants from a varied, produce-rich diet rather than high-dose pills (see Supplements — A Skeptical Note on Ineffective and Risky Products).
Key facts
- Neutralize free radicals; counter oxidative stress.
- Sources: vitamins C and E, carotenoids, selenium, plant polyphenols.
- Whole-food, produce-rich diets are protective; isolated high-dose supplements are not (some harm).
- High-dose vitamin C/E around training can blunt mitochondrial/hypertrophy adaptations.
- Prefer food sources over supplements.
Connections
- Vitamins — Fat-Soluble vs Water-Soluble Overview — vitamins C and E as antioxidants.
- Supplements — A Skeptical Note on Ineffective and Risky Products — why antioxidant pills aren't recommended.
- Muscle Hypertrophy — adaptation signaling that megadoses may blunt.
- Recovery Modalities — Overview & Evidence — oxidative stress and recovery context.
Sources
See how this applies in practice, with honest limits on what the plan changes.
Educational content only — not medical advice. Always consult a qualified professional for individualized guidance, especially around injury, pregnancy, or medical conditions.