An interventional study of Ashwagandha and Placebo in Strength, Stress and Exercise Adaptation, sponsored by Sports Performance and Applied Research in Trials and Analysis. Not yet recruiting. Open to participants aged 11 Years to 19 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by Sports Performance and Applied Research in Trials and Analysis · Not applicable, Interventional, and Basic science
This study will test whether six weeks of ashwagandha (KSM-66 root extract), helps teenage footballers recover and improve strength. Very little research has looked at young people aged 11 to 19, despite increased usage in this cohort.
About 50 to 60 male and female players from grassroots clubs in Sussex, Surrey and Greater London will be randomly assigned to take a daily capsule of either 450 mg ashwagandha or a placebo in an unblinded fashion. Before and after the six weeks, players will do tests at their usual training site: saliva samples to measure the cortisol, grip strength, a 1 km time trial, and short questionnaires on recovery, sleep, stress and soreness.
The results will show whether ashwagandha changes stress, strength, performance and perceived recovery over six weeks.
This randomised, double-blind, placebo-controlled trial will test whether KSM-66 ashwagandha (Withania somnifera) root extract alters physiological stress, neuromuscular performance and perceived recovery in adolescent footballers. In adults, standardised root extract has been associated with improved strength, recovery, sleep and reduced cortisol. In children, the only placebo-controlled trial of root extract (ages 6 to 12) examined cognition and sleep. No trial has studied adolescents, whose growth, maturation and training load may alter responses, so adult findings cannot be assumed to apply.
An independent collaborator outside the research team will generate the allocation (block size four, stratified by sex and age band, 11 to 15 and 16 to 19) and label bottles with participant codes only. Participants, caregivers and investigators will remain blind until the dataset is locked, and blinding success will be assessed at follow-up. Players aged 11 to 15 take part with parental consent and their own assent, and players aged 16 to 19 consent for themselves. A study medical official will screen medical eligibility. Caregivers or participants will be contacted weekly regarding adverse events, and any suspected supplement-related event will lead to discontinuation and medical review within 24 hours.
Data will be analysed by linear mixed methods. Two investigators will analyse the coded data independently and blind to allocation. Results will be interpreted as short-term responses and will not establish long-term safety or efficacy.
Sports Performance and Applied Research in Trials and Analysis is the lead sponsor of 4 studies on the registry; 3 are open to participants now.
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Exclusion Criteria:
450mg of KSM-66 Ashwagandha
Dietary Supplement: Ashwagandha
450mg corn starch
Dietary Supplement: Placebo
One 450 mg capsule of KSM-66 ashwagandha, taken once daily with a meal for six weeks (42 days). KSM-66 is a full-spectrum extract made from root only, with no leaf, standardised to 5% withanolides (HPLC verified), and supplied with a certificate of analysis for each batch. Capsules are supplied in labelled bottles of 42 and are identical in appearance to the placebo.
Also known as: KSM-66
One 450 mg capsule of corn starch, taken once daily with a meal for six weeks (42 days). The capsule shell, appearance, bottle and labelling are identical to the active capsule.
Salivary cortisol
Saliva collected with Salivette tubes after an evening training session and analysed by an external laboratory. Reported as the change from baseline to follow-up.
Time frame: Baseline (week 0) and after six weeks of supplementation
Salivary alpha-amylase
Measured from the same saliva samples as cortisol.
Time frame: Baseline (week 0) and after six weeks of supplementation
Handgrip Strength
Maximal handgrip strength measured with a CAMRY handgrip dynamometer.
Time frame: Baseline (week 0) and after six weeks of supplementation
Number of participants with adverse events
Any adverse events reported in the duration of the clinical trial
Time frame: Baseline (week 0) and after six weeks of supplementation
Change in perceived recovery, measured by the Hooper Index
Self-reported fatigue, stress, sleep quality and muscle soreness on the Hooper Index questionnaire. Individual items are scored 1 (very, very good) to 10 (very, very bad) and the total score is 4 to 40, higher scores indicating poorer recovery.
Time frame: Baseline (week 0) and after six weeks of supplementation
Change in 1 km time-trial performance
Time taken to complete a 1 km run, as a measure of aerobic fitness and high-intensity running capacity.
Time frame: Baseline (week 0) and after six weeks of supplementation
No study locations are listed for this record.
Plan to share: No — Individual participant data will not be shared. Participants will be minors recruited from a small number of local football clubs, so a dataset of this size (about 50 to 60 players) combined with age, sex and test results could allow re-identification even after coding. Consent and assent were obtained for use of the data within this study only, and the participant code key and contact details will be permanently deleted on 31 May 2027. The fully anonymised dataset will be held securely by the research team and used only for the analyses and publications described in the ethics-approved protocol. Summary results will be reported in the results section of this record and in peer-reviewed publication, with participating clubs not named.
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Ashwagandha
Sports Performance and Applied Research in Trials and Analysis