Adjunctive Ashwagandha (Withania somnifera) Supplementation and Resistance-Training Adaptations in Healthy Adults: A Systematic Review and Random-Effects Meta-Analysis of Muscular Strength, Chest Circumference, and Body Composition
Study Details
This new meta-analysis examined whether ashwagandha enhances resistance-training adaptations in healthy adults, identifying 4 eligible RCTs, with 3 trials and 161 participants included in the pooled analysis 🔍
Here are the key findings ⬇️
Key Findings
💪 Ashwagandha produced greater gains in 1-RM bench press than placebo (SMD = 0.60)
🦵 Lower-body 1-RM also improved more with ashwagandha (SMD = 0.52)
📏 Chest circumference increased more with ashwagandha (SMD = 0.86), but this was based on only 2 trials and is an indirect surrogate for hypertrophy
🔥 Body-fat percentage did not clearly improve in the primary analysis (SMD = −0.32)
⚠️ The body-fat result was unstable, becoming significant when one trial with implausibly precise data was removed
📉 Both strength effects lost statistical significance after small-sample adjustment, highlighting the fragility of the findings
🧩 Leave-one-out analyses also showed that each strength result depended heavily on a single influential trial
📊 Evidence certainty was Low for bench press, lower-body strength and body fat, and Very Low for chest circumference
🏋️ Studies used standardised extracts at 500–600 mg/day for 8–12 weeks alongside structured resistance training
🧪 A fourth eligible preprint was not pooled because its reported bench-press values were not interpretable as absolute loads
💰 All 3 pooled trials were funded or supplied by ashwagandha manufacturers
⚠️ The review also notes an uncommon safety signal for ashwagandha-associated liver injury
Conclusion
Ashwagandha may modestly enhance strength gains when added to resistance training, but the evidence is currently too small and fragile to treat it as a well-established ergogenic aid; training, protein and creatine remain better-supported priorities ✅
Reference
https://pubmed.ncbi.nlm.nih.gov/42738987/
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