Effects of Root Extract Ashwagandha (KSM-66) on Physiological Stress, Perception of Recovery and Muscle Strength in Youth Footballers

May 12, 2026 updated by: Sports Performance and Applied Research in Trials and Analysis

This trial examines if six weeks of taking 450 mg Ashwagandha root extract affects exercise performance and recovery in youth male elite football players.

Ashwagandha root extract is increasingly used by athletes, but controlled research in adolescent athletes is limited and the majority of evidence is in an adult population. This study will assess short-term responses in youth players.

Participants will be randomly assigned to take either Ashwagandha root extract or a placebo once daily for six weeks. Players will complete training-based tests, provide saliva samples and complete a short, validated questionnaire on perception of wellness. Any adverse events will be documented and reported.

Study Overview

Status

Suspended

Conditions

Intervention / Treatment

Detailed Description

The objective of this trial is to learn whether a short period of taking 450mg of Ashwagandha root extract affects performance, recovery, muscle strength and wellbeing in youth male elite football players.

The researchers are studying Ashwagandha root extract as it is increasingly used by athletes and the general population of varying ages for well-being, performance and recovery purposes, despite a lack of controlled research examining its effects in adolescent athletes. Most existing evidence comes from adult populations, and it remains unclear whether similar physiological and perceptual responses occur in adolescents engaged in structured training.

The main questions the study aims to answer are:

Does taking Ashwagandha root extract change stress levels measured through saliva in youth elite footballers?

Does it affect muscle strength, recovery, sleep, or muscle soreness?

Participants will be randomly assigned to take either Ashwagandha root extract or a placebo once a day for six weeks. During the study, players will complete strength and fitness tests during usual training time, then provide saliva samples afterwards. Short questionnaires will be solicited the day after about how they feel. Any adverse events that occur during the study will be documented and reported.

Study Type

Interventional

Enrollment (Actual)

62

Phase

  • 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

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

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Male youth football player
  • Classified as 'healthy' and 'free of disease'
  • Actively training with the selected football academy

Exclusion Criteria:

  • Lack of signed consent form
  • No active use of medication
  • No active use of ergogenic aids
  • Allergies to nightshades

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: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Ashwagandha root extract
450 mg Ashwagandha root extract
Dietary supplement: Root extract Ashwagandha
450 mg Ashwagandha root extract
Placebo Comparator: Placebo
450 mg corn starch
Other: Corn Starch
450 mg corn starch

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change in Salivary Cortisol Concentration from Baseline to 6 Weeks
Time Frame: 6 weeks
6 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Salivary Alpha Amylase from Baseline to 6 Weeks
Time Frame: 6 weeks
6 weeks
Change in Handgrip Strength (kg) from Baseline to 6 Weeks
Time Frame: 6 weeks
Hand grip strength using CAMRY dynamometer
6 weeks
Change in Countermovement Jump Height (cm) from Baseline to 6 Weeks
Time Frame: 6 weeks
6 weeks
Change in 1 km Time Trial Completion Time (seconds) from Baseline to 6 Weeks
Time Frame: 6 weeks
Maximal effort run of 1km
6 weeks
Perception of sleep quality
Time Frame: Baseline to 6 weeks
Sleep quality will be assessed using the sleep domain of the Hooper Index, which is one of four domains within the questionnaire (fatigue, stress, delayed onset muscle soreness, and sleep). The sleep item is rated on a 10-point scale (1 to 10), where 1 indicates very, very good sleep and 10 indicates very, very poor sleep. This domain will be analysed independently as a subset of the Hooper Index, rather than as part of the total score.
Baseline to 6 weeks
Perception of stress
Time Frame: Baseline to 6 weeks
Perceived stress will be assessed using the sleep domain of the Hooper Index, which is one of four domains within the questionnaire (fatigue, stress, delayed onset muscle soreness and sleep). The stress item is rated on a 10-point scale (1 to 10), where 1 indicates very, very good and 10 indicates very, very poor. This domain will be analysed independently as a subset of the Hooper Index, rather than as part of the total score.
Baseline to 6 weeks
Perception of muscle soreness
Time Frame: Baseline to 6 weeks
Perceived muscle soreness will be assessed using the sleep domain of the Hooper Index, which is one of four domains within the questionnaire (fatigue, stress, delayed onset muscle soreness and sleep). The muscle soreness item is rated on a 10-point scale (1 to 10), where 1 indicates very, very good and 10 indicates very, very poor. This domain will be analysed independently as a subset of the Hooper Index, rather than as part of the total score.
Baseline to 6 weeks
Perception of fatigue
Time Frame: Baseline to 6 weeks
Perceived fatigue will be assessed using the sleep domain of the Hooper Index, which is one of four domains within the questionnaire (fatigue, stress, delayed onset muscle soreness and sleep). The fatigue item is rated on a 10-point scale (1 to 10), where 1 indicates very, very good and 10 indicates very, very poor. This domain will be analysed independently as a subset of the Hooper Index, rather than as part of the total score.
Baseline to 6 weeks
Overall Hooper Index Score
Time Frame: Baseline to 6 weeks
Perceived recovery will be assessed using the Hooper Index, which evaluates four domains: fatigue, stress, delayed onset muscle soreness (DOMS) and sleep quality. Each domain is rated on a 10-point scale (1 to 10), where 1 indicates very, very good and 10 indicates very, very poor. The total Hooper Index score is calculated by summing the four domains, resulting in a possible range of 4 to 40, with higher scores indicating worse perceived recovery, greater fatigue and stress, and lower scores indicating better recovery.
Baseline to 6 weeks

Collaborators and Investigators

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

Sponsor

Sports Performance and Applied Research in Trials and Analysis

Collaborators

Fulham Football Club

Investigators

  • Study Director: Olivia C Coope, PhD, Blanquerna Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

January 6, 2026

Primary Completion (Estimated)

July 17, 2026

Study Completion (Estimated)

July 18, 2026

Study Registration Dates

First Submitted

January 6, 2026

First Submitted That Met QC Criteria

January 6, 2026

First Posted (Actual)

January 15, 2026

Study Record Updates

Last Update Posted (Actual)

May 15, 2026

Last Update Submitted That Met QC Criteria

May 12, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20251103

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data related to primary and secondary outcomes will be shared with other sports nutrition researchers upon reasonable request. Data sharing will be subject to ethical approval, data protection requirements, and safeguarding considerations, and will exclude any information that could identify participants.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

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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