Ashwagandha and endurance performance: grade B

Moderate evidence. Direction: Benefit.

B ModerateShort-term only

Educational guidance, not medical advice

Why this grade

Rubric condition met: Meta-analysis with high heterogeneity (I2 = 60%, prediction interval crosses zero)

A 2026 three-level meta-analysis of 13 RCTs (599 participants, mainly young adults or athletes) found the most consistent evidence for aerobic endurance, but the overall prediction interval crossed zero. An earlier meta-analysis found higher VO2max with high heterogeneity.

How we grade evidence

Studies this grade rests on

each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.

Show the numbers

Study	Year	Design	Participants	Result
Effects of Ashwagandha (Withania 2020	2020	meta-analysis	162	result not recorded
Li 2026	2026	meta-analysis	599	result not recorded

Effects of Ashwagandha (Withania somnifera) on VO(2max): A Systematic Review and Meta-Analysis.

Pérez-Gómez J, Villafaina S, Adsuar JC. Effects of Ashwagandha (Withania somnifera) on VO(2max): A Systematic Review and Meta-Analysis Nutrients, 2020. PMID 32316411

Result not recorded

Design: Systematic review and meta-analysis (5 studies reviewed, 4 pooled)
Sample: n = 162
Population: Healthy adults and athletes
Funding: not stated

Effects of Withania somnifera (Ashwagandha) Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-Analysis.

Li X, Li H, Yao S. Effects of Withania somnifera (Ashwagandha) Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-Analysis Nutrients, 2026. PMID 42356302

Result not recorded

Design: Systematic review and three-level meta-analysis of 13 RCTs
Sample: n = 599
Population: Mainly young adults or athletes
Funding: National Education Science Planning Foundation of China, National Education Science Planning Foundation of China No.BLA230107

Search and history

Search (November 11, 2026): ashwagandha[ti] AND (strength[tiab] OR muscle[tiab] OR VO2max[tiab] OR exercise[tiab]) AND (meta-analysis[pt] OR systematic review[pt])

November 11, 2026 Graded B (proposed): Proposed in the monograph draft
November 13, 2026 B to B (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page