Researchers in the Netherlands, Spain and the UK recruited 56 healthy male and female sub-elite team sport athletes to receive either 600 mg/day of Ixoreal Biomed’s branded ashwagandha root extract, KSM-66 or a placebo over six weeks.
The research was conducted to fill the research gap on the effects of ashwagandha supplementation in athletes involved in contact and team sports who face unique pre-season stressors.
After assessing salivary cortisol and cortisone levels, perceived recovery and muscle strength, the researchers reported that the “findings are particularly relevant given that pre-season training has previously been shown to elicit elevations in stress-related hormonal responses.”
Pre-season training spikes cortisol
Pre-season training can elevate cortisol levels and impair recovery, sleep, immune function and muscle repair, increasing the risk of overtraining and injury, particularly in contact and team sports where athletes regularly perform high-intensity sprints, collisions and rapid changes of direction.
These demands place high levels of stress on the neuromuscular and endocrine systems, activating the hypothalamic–pituitary–adrenal (HPA) axis and increasing cortisol and cortisone secretion, which has been linked to fatigue, disrupted sleep and reduced performance.
Pre-season recovery strategies include prioritizing high-quality sleep, muscle repair and hormonal regulation. The adaptogenic herb ashwagandha (Withania somnifera) has been found to reduce stress, improve recovery and enhance physical performance.
Clinical trials and meta-analyses show that standardized ashwagandha root extracts consistently lower cortisol levels, improve well-being and enhance muscle strength and endurance across a range of doses and supplementation periods. These effects likely occur through modulation of the HPA axis, improving stress resilience and sleep quality.
Ashwagandha could help regulate cortisol in athletes
The randomized, double-blind, placebo-controlled trial recruited competitve rugby, water polo and soccer players from a professional sports academy in Barcelona, Spain and randomly assigned them, with equal sex distribution, to either a supplement or placebo group.
The researchers assessed salivary stress hormones, muscle strength, aerobic fitness and perceived recovery at baseline and post-intervention.
Athletes provided post-training saliva samples to measure cortisol and related biomarkers, while perceived recovery was assessed using a validated questionnaire. The study measured strength using handgrip dynamometry, one-repetition maximum lifts, jump tests and pull-ups, and evaluated aerobic fitness using a shuttle run test.
After baseline testing, participants consumed either the supplement or a visually-matched placebo for 42 days and were monitored for adherence, adverse events and supplement satisfaction throughout the study.
Results showed that in females, cortisol increased significantly over the pre-season in the placebo group, while no such increase occurred in the ashwagandha group. In males, cortisone increased significantly in the placebo group but remained stable with ashwagandha.
Perceived recovery also only improved in female athletes, with the supplemented group reporting significant improvements in overall recovery, muscle soreness and fatigue, while no recovery changes were observed in males. However, male athletes in the ashwagandha group showed a significant increase in countermovement jump height, which female athletes did not.
“Although this study was not specifically designed to investigate sex differences, it is notable that males and females differed across several outcomes,” the researchers wrote. “These differences may reflect physiological factors such as hormonal variations, differences in muscle mass or neuromuscular function and training history.”
They elaborated that females often show stronger and more sustained activation of the HPA axis under certain stressors, while men typically exhibit larger adrenocorticotropic hormone and cortisol surges during performance-related stress.
“While these findings highlight the potential efficacy of ashwagandha root extract, further research is warranted to refine its role in athletic settings,” the researchers concluded.
“Future studies may wish to explore optimal dosing strategies, supplementation duration and timing relative to training load. Incorporating crossover designs and longitudinal follow-ups could also enhance the understanding of ashwagandha’s sustained effects on performance and adaptation throughout the competitive season.”
Nutrients; doi: 10.3390/nu18020230. “Ashwagandha Root Extract Stabilises Physiological Stress Responses in Male and Female Team Sports Athletes During Pre-Season Training”. Authors: O. C. Coope et al.
