Do plant-based diets affect athletic performance?
Plant-based diet athletic performance: 8 trials found no significant strength difference, and a 10-study review pooled an aerobic effect size of 0.55.
In a 2025 meta-analysis of eight randomised trials (188 adults), plant-based and omnivorous diets did not differ significantly in muscular strength. An earlier meta-analysis of 10 studies pooled a moderate advantage for plant-based diets in aerobic performance (effect size 0.55), but from only four studies. Both reviews are small, and neither abstract reports on elite competition.
What did the 2025 strength meta-analysis find?
López-Moreno et al., Sports Medicine Open 2025 searched four databases up to September 2024 for randomised trials comparing plant-based with omnivorous diets. Eight trials qualified (five vegetarian, three vegan), with 188 participants, 46% of them women, aged 20 to 65 on average. Interventions lasted 10 days to 12 weeks, and participants ranged from sedentary adults to recreational athletes and CrossFit-trained people.
Pooled standardised mean differences, where positive favours plant-based, were -0.12 for upper body strength (95% CI -0.50 to 0.27), 0.18 for lower body strength (-0.31 to 0.67) and 0.21 for overall strength (-0.16 to 0.58). None was statistically significant. The confidence intervals are wide, so small differences in either direction cannot be excluded. The authors call for further work on key nutrients and long-term effects.
What about aerobic performance and elite athletes?
Damasceno et al., British Journal of Nutrition 2024 pooled 10 studies with 293 physically active participants (four vegan, six lacto-ovo-vegetarian; searches to June 2022). Aerobic performance, in four studies, showed an effect size of 0.55 (95% CI 0.29 to 0.81) favouring plant-based diets. Strength and power, in six studies, showed -0.30 (95% CI -0.67 to 0.07), not significant. The abstract does not state whether the included studies were randomised.
Neither abstract reports elite competition results. With so few studies behind the aerobic figure, it reads as a signal for larger, longer trials, not a settled effect.
Protein intake is often the first question about strength on any diet, and the evidence on how much protein is covered separately.
The bottom line
- Eight randomised trials (188 adults, 10 days to 12 weeks) found no significant strength difference between plant-based and omnivorous diets (overall standardised mean difference 0.21, 95% CI -0.16 to 0.58).
- An earlier review pooled an aerobic effect size of 0.55 (95% CI 0.29 to 0.81) from four studies, and no significant strength or power difference.
- Both reviews were small and short, and neither abstract reports elite competition results.
Frequently asked questions
- Do plant-based diets reduce muscular strength?
- In a 2025 meta-analysis of eight randomised trials (188 adults, 10 days to 12 weeks), pooled strength differences between plant-based and omnivorous diets were not statistically significant (overall standardised mean difference 0.21, 95% CI -0.16 to 0.58). The trials were small and short, so small differences either way cannot be excluded.
- Do plant-based diets improve endurance performance?
- A 2024 meta-analysis pooled a moderate advantage in aerobic performance with plant-based diets (effect size 0.55, 95% CI 0.29 to 0.81), but from only four studies. It is a signal that needs larger, longer trials before it can be called an established effect.
Sources
- López-Moreno M, Viviani Rossi E, López-Gil JF, et al., 2025. Are Plant-Based Diets Detrimental to Muscular Strength? A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Sports Medicine - Open 11, article 62.
- Damasceno YO, Leitão CVFS, Oliveira GM, Andrade FAB, Pereira AB, Viza RS, Correia RC, Campos HO, Drummond LR, Leite LHR, Coimbra CC, 2024. Plant-based diets benefit aerobic performance and do not compromise strength/power performance: a systematic review and meta-analysis. British Journal of Nutrition 131(5):829-840.