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

August 29, 2025 updated by: Blanca Roman-Viñas, MD, University Ramon Llull

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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
56

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Spain
      • Barcelona, Spain
        • Club Natació Poble Nou

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Cortisol
Time Frame: Baseline and final measurement at 6 weeks
Salivary cortisol
Baseline and final measurement at 6 weeks
Hand grip
Time Frame: Baseline and final measurement at 6 weeks
Hand grip strength in kilograms, CAMRY dynanometer
Baseline and final measurement at 6 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Testosterone
Time Frame: Baseline and final measurement at 6 weeks
Salivary testosterone
Baseline and final measurement at 6 weeks
Melatonin
Time Frame: Baseline and final measurement at 6 weeks
Salivary melatonin
Baseline and final measurement at 6 weeks
DHEA-s
Time Frame: Baseline and final measurement at 6 weeks
Salivary DHEA-s
Baseline and final measurement at 6 weeks
Alpha-amylase
Time Frame: Baseline and final measurement at 6 weeks
Salivary alpha-amylase
Baseline and final measurement at 6 weeks
Cortisone
Time Frame: Baseline and final measurement at 6 weeks
Salivary cortisone
Baseline and final measurement at 6 weeks
Bronco test
Time Frame: Baseline and final measurement at 6 weeks
Aerobic fitness test in minutes and seconds
Baseline and final measurement at 6 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Ramon Llull

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 12, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 31, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 25, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 19, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 19, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 27, 2025

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 2, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 29, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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