The effects of vitamin C and E on exercise-induced physiological adaptations: a systematic review and Meta-analysis of randomized controlled trials

• Published in: Critical reviews in food science and nutrition 2020-11, Vol.60 (21), p.3669-3679
• Main Authors: Clifford, Tom, Jeffries, Owen, Stevenson, Emma J., Davies, Kelly A. Bowden
• Format: Article
• Language: English
• Subjects: Adaptation; Adaptation, Physiological - drug effects; Adult; Aerobic capacity; Aerobics; Antioxidant; Ascorbic acid; Ascorbic Acid - administration & dosage; Clinical trials; Dietary Supplements; endurance performance; Exercise; Humans; Meta-analysis; Muscle strength; Physical fitness; Physical training; Physiological effects; Physiology; Randomized Controlled Trials as Topic; Resistance training; skeletal muscle; Systematic review; Training; vitamin; Vitamin C
• ISSN: 1040-8398; 1549-7852
• DOI: 10.1080/10408398.2019.1703642

We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity ( O 2max) (SMD −0.14, 95% CI: −0.43 to 0.15, P = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, P = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, P = 0.67) and (SMD −0.15, 95% CI: −0.16 to 0.46, P = 0.35), respectively. There was also no influence of age on any of these outcomes (P > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.