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

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

This double-blind, randomised, placebo-controlled trial will examine the effects of 42-day root extract ashwagandha (KSM-66) supplementation on recovery and muscle strength in male and female rugby and water polo players. Participants will receive either 600 mg of ashwagandha or a placebo daily. Outcomes include hormonal stress markers, perceived exertion, wellness, muscle soreness and strength and performance metrics (grip strength, jump tests, 1RM lifts, Bronco test).

Study Overview

• Status: Completed
• Conditions: Recovery; Exercise Training; Strength
• Intervention / Treatment: Dietary supplement: KSM-66 Ashwagandha; Dietary supplement: Placebo

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona, Spain
    • Club Natació Poble Nou

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Above the age of 18
• Healthy and free of disease
• Assigned as an athlete at CN Poble Nou sports academy

Exclusion Criteria:

• Allergies to nightshades such as tomato, aubergine, potatoes and peppers
• Active supplementation with other ergogenic aids (to not interfere with existing treatment)
• Medication or contraceptives (to not interfere with existing treatment)
• Liver conditions (to not interfere with existing treatment)
• Thyroid conditions (to not interfere with existing treatment)
• Diabetes or certain autoimmune conditions (to not interfere with existing treatment)
• Active pregnancy (to not interfere with existing treatment)
• No signing of the consent form

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: KSM-66 Ashwagandha; 600mg root extract KSM-66 Ashwagandha, once daily taken with dinner	Dietary supplement: KSM-66 Ashwagandha; Root extract ashwagandha, KSM-66
Placebo Comparator: Placebo; 600mg organic chickpea flour, once daily taken with dinner	Dietary supplement: Placebo; Organic chickpea flour

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cortisol	Salivary cortisol	Baseline and final measurement at 6 weeks
Hand grip	Hand grip strength in kilograms, CAMRY dynanometer	Baseline and final measurement at 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Testosterone	Salivary testosterone	Baseline and final measurement at 6 weeks
Melatonin	Salivary melatonin	Baseline and final measurement at 6 weeks
DHEA-s	Salivary DHEA-s	Baseline and final measurement at 6 weeks
Alpha-amylase	Salivary alpha-amylase	Baseline and final measurement at 6 weeks
Cortisone	Salivary cortisone	Baseline and final measurement at 6 weeks
Bronco test	Aerobic fitness test in minutes and seconds	Baseline and final measurement at 6 weeks

Collaborators and Investigators

• Sponsor: University Ramon Llull

Study record dates

Study Major Dates

• Study Start (Actual): June 12, 2025
• Primary Completion (Actual): July 31, 2025
• Study Completion (Actual): August 25, 2025

Study Registration Dates

• First Submitted: June 19, 2025
• First Submitted That Met QC Criteria: June 19, 2025
• First Posted (Actual): June 27, 2025

Study Record Updates

• Last Update Posted (Estimated): September 2, 2025
• Last Update Submitted That Met QC Criteria: August 29, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: recovery; cortisol; performance; athlete; ashwagandha
• Additional Relevant MeSH Terms: Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: 05-03-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD will be made available upon reasonable request for academic research purposes.
• IPD Sharing Supporting Information Type: ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No