Nutrition Lab: Ashwagandha, Cortisol and Athletic Performance
Ashwagandha is everywhere. On social media, in supplement stacks, in biohacker recommendations. But beyond the marketing noise, a study published in January 2026 in Nutrients provides solid data on its actual effects in athletes undergoing intensive physical preparation.
56 team sport athletes. 42 days of supplementation. Results that deserve careful reading, because they don't say exactly what supplement brands would like you to take away.
What the Study Measured
Researchers from the University of Chichester recruited 56 rugby, water polo, and football athletes during their pre-season, a period when training volume peaks and physiological stress hits its maximum. The test group received 600 mg/day of ashwagandha root extract for 42 days. The control group received a placebo.
Researchers measured salivary stress biomarkers (cortisol and cortisone), perceived recovery via the Hooper Index (sleep, stress, fatigue, soreness), explosive strength via the countermovement jump (CMJ), and aerobic capacity via the Yo-Yo test.
Results in Female Athletes
The clearest results came from the female athletes. In the placebo group, salivary cortisol increased significantly over the course of pre-season. That's expected: repeated intensive training drives cortisol up. But in the ashwagandha group, that increase didn't happen. Cortisol stayed stable.
At the same time, perceived recovery scores improved significantly in the ashwagandha group. The overall Hooper Index, DOMS scores, and perceived fatigue all decreased compared to placebo. The athletes taking ashwagandha felt better recovered, despite the same training volume.
One important note: explosive strength (CMJ) didn't increase significantly in women. The benefits were concentrated in stress management and recovery.
Results in Male Athletes
In men, the pattern was different. Salivary cortisone (a cortisol metabolite) increased significantly in the placebo group but not in the ashwagandha group. The performance difference showed up in explosive power: the ashwagandha group showed a significant increase in CMJ jump height.
Perceived recovery scores also improved, but less dramatically than in women.
What This Confirms and What It Doesn't Say
This study confirms what a meta-analysis published in BJPsych Open had already shown: ashwagandha at 500-600 mg/day consistently reduces cortisol levels and improves stress and anxiety markers in adults.
An important detail highlighted by News Medical's analysis: ashwagandha didn't blunt training adaptation. Athletes in the supplementation group continued to progress on performance tests. That's a critical distinction. The supplement stabilizes stress without blocking the adaptation signal, making it a recovery tool rather than a brake on progression.
What the study doesn't tell us: whether these benefits persist long-term beyond 42 days, whether the results transfer to individual sports like weight training or running, and whether doses below 600 mg would produce the same effects.
What This Means for Your Training
If you train regularly at high intensity and you're feeling accumulated fatigue, ashwagandha at 600 mg/day is an option backed by solid data. The Nutrition & Metabolism review (2025) synthesizes the mechanisms: cortisol reduction, sleep improvement, muscular recovery support.
Don't expect a direct performance boost. Ashwagandha won't make you stronger overnight. Its primary effect is protecting your ability to recover when training volume is high, which, over time, allows you to train more consistently.
Go with a standardized root extract (like KSM-66 or Sensoril), at 600 mg/day, in one or two doses. The 2026 study used this dose and form. Doses below 300 mg have shown less consistent results in the literature.
Also read: Creatine and Your Brain: What the 2026 Research Shows