The Effects of Strength Training Combined with Vitamin C and E Supplementation on Skeletal Muscle Mass and Strength: A Systematic Review and Meta-Analysis
What this study found
Overall, chronic vitamin C and E supplementation did not improve muscle strength or hypertrophy during resistance training. In the meta-analysis of isokinetic strength from 3 studies, the pooled effect was not significant (MD = 5.09 N/m; 95% CI: -1.39 to 11.41; P = 0.13; experimental n = 37; control n = 34). Individual trials were mostly null for hypertrophy, although some reported smaller muscle size gains with antioxidants, such as greater rectus femoris thickness increase in placebo than in antioxidants (+3.4 mm vs +1.9 mm) and no meaningful differences in several strength outcomes. The…
- Study & population
- This was a systematic review and meta-analysis of resistance-training studies in adults and older adults, including healthy and nonhealthy participants, trained and sedentary individuals, and both men and women.
- Intervention
- Chronic vitamin C and vitamin E supplementation was given alongside resistance training across the included trials, most commonly vitamin C 1000 mg/day combined with vitamin E 235 mg/day, 400 IU/day, or 600 mg/day depending on the study.
- Key limitation
- The evidence base was small and heterogeneous, with only 3 studies contributing to the pooled strength analysis.
View source
Open PDFOriginal abstract
Intense muscle contractile activity can result in reactive oxygen species production in humans. Thus, supplementation of antioxidant vitamins has been used to prevent oxidative stress, enhance performance, and improve muscle mass. In this sense, randomized controlled studies on the effect of vitamin C and E supplementation combined with strength training (ST) on skeletal muscle mass and strength have been conducted. As these studies have come to ambiguous findings, a better understanding of this topic has yet to emerge. The purpose of the present review is to discuss the current knowledge about the effect of vitamin C and E supplementation on muscle mass and strength gains induced by ST. Search for articles was conducted in the following databases: PubMed/Medline, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Google Scholar. This work is in line with the recommendations of the PRISMA statement. Eligible studies were placebo-controlled trials with a minimum of four weeks of ST combined with vitamin C and E supplementation. The quality of each included study was evaluated using the Physiotherapy Evidence Database Scale (PEDro). 134 studies were found to be potentially eligible, but only seven were selected to be included in the qualitative synthesis. A meta-analysis of muscle strength was conducted with 3 studies. Findings from these studies indicate that vitamins C and E has no effect on muscle force production after chronic ST. Most of the evidence suggests that this kind of supplementation does not potentiate muscle growth and could possibly attenuate hypertrophy over time.