The Effects of KSM-66 Ashwagandha (Withania Somnifera) Supplementation on Recovery and Muscle Strength in Academy Athletes

This double-blind, randomised, placebo-controlled trial aims to investigate the effects of ashwagandha (ASH) supplementation on recovery and muscle strength in male and female rugby and water polo players. Participants will supplement either KSM-66 ashwagandha (600 mg, standardised to 5% withanolides) or a placebo once daily for 42 days. The study will evaluate outcomes related to hormonal stress markers, perceived exertion, wellness, muscle soreness, and physical performance.

Primary biomarkers include cortisol, DHEA-S, testosterone, melatonin, alpha-amylase, and cortisone, assessed through saliva samples. Subjective measures will include the Borg Rate of Perceived Exertion Scale and the Hooper Index for sleep quality, stress, fatigue, and delayed onset muscle soreness (DOMS). Physical performance will be assessed using grip strength (CAMRY dynamometer), vertical jump tests (countermovement jump, squat jump), broad jump, 1-repetition maximum (1RM) tests for deadlift, bench press, and pull-up, as well as the Bronco test. Supplement satisfaction will be evaluated via questionnaire.

Participants' dietary intake will be recorded using a self-tracking method (Snap-N-Send) and analysed using Nutritics software; food diaries will serve as covariates in the final analysis. The study will be conducted in partnership with CN Poble Nou, a professional sports club in Barcelona, Spain.

Ashwagandha use is increasingly common among athletes despite limited evidence on appropriate dosing and performance outcomes. This study will contribute to scientific understanding of its potential short-term benefits, particularly in high-contact sports where managing cortisol and recovery is critical.

All participants will provide informed consent, and ethical considerations focus on safety, data privacy, and the right to withdraw from the study at any time.