The goal of this clinical trial is to evaluate the effects of short-term root extract ashwagandha supplementation on exercise performance in female footballers. The main question it aims to answer are:

Will short-term supplementation of root extract ashwagandha improve muscle strength markers in female footballers? Will short-term supplementation of root extract ashwagandha improve perception of recovery following high-intensity exercise in female footballers?

Participants will either supplement 600mg (5% withanolides) root extract ashwagandha or placebo once a day for 28 days. There will be three data points: baseline, 14 days and 28 days. Researchers will compare values of intervention against placebo to see if there is an effect on muscle strength or perception of recovery.

The objectives of the thesis are to determine the effects of ashwagandha (ASH) on muscle strength, muscle recovery and to assess habitual dietary intake of female footballers. Across one phase, two experimental research papers and one descriptive research paper will be produced; it will involve one double-blind, randomised and placebo-controlled trial and a comparative analysis of nutritional intake in female footballers. The thesis will involve participants supplementing ASH in the form of a capsule containing KSM-66 (600 mg with 30mg withanolides) or placebo once a day for 28 days, on a singular occasion. The objectives of the first two papers are to determine the effects of ASH on muscle strength, perception of recovery, perception of exertion, perceived wellness and perceived muscle soreness. For the paper on muscle strength, the methodology will include hand grip test, counter movement jump (CMJ), squat jump (SJ), peak power, medicine ball throw and rate of perceived exertion (RPE) via the Borg Scale. For the paper on muscle recovery, the methodology will include a questionnaire on sleep, stress, fatigue and delayed onset of muscle soreness (DOMS) test via the Hooper Index (HI), total quality recovery (TQR) questionnaire and a supplement satisfaction questionnaire. The objectives of the third paper are to evaluate the dietary intake of professional female footballers and compare the values against published nutritional recommendations. The participants diets will be tracked for purposes of the muscle strength and recovery study. The methodology will involve self-tracking of dietary intake via the Snap-N-Send method and data will be stored and analysed with the software Nutritics. The study will be conducted with a professional club in Barcelona. The use of ASH is becoming prevalent in athletes, despite lack of information regarding dosage guidelines or lack of research on its benefits for exercise performance. The proposed study will contribute to the overall scientific knowledge of ASH and whether it may demonstrate benefits from short-term use. Additionally, the study will determine if there are benefits for female athletes that wish to increase strength and reduce perception of pain or soreness related to exercise. The ethical considerations for this study are predominantly the safety and comfort of the participant. An informed consent form will be given to the participant, containing information about data collection, personal information, safety of the supplement and their right to drop out of the study at any point. The proposed start date is January 2024, and the study will aim to collectively last for 36 days across a singular phase. The supplement is provided by Zenement España, a supplement company based in Barcelona.

Inclusion Criteria:

• Female
• Playing football professionally
• At a sub-elite to elite standard
• Healthy and free of disease

Exclusion Criteria:

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

Participants must be female or assigned female at birth

Female, healthy, over 18 years of age, footballer assigned to a professional club.

One month

Adverse events were defined in accordance with ClinicalTrials.gov standards including any medical occurrences regardless of relation to the intervention. Serious adverse events included any events resulting in death, life-threatening situations, hospitalisation or significant disability. Data were collected over one month, with monitoring conducted weekly based on participant self-reports and investigator assessments. No differences in definition were applied from the standard ClinicalTrials.gov

No clinical testing, such as blood biomarkers, to correlate physiological data with observed outcomes, limiting conclusions about ashwagandha's biochemical effects on muscle strength and recovery. Sleep quality was self-reported - future studies should use objective methods. The convenience sample limits generalisability, and larger samples are needed. Lack of a crossover design also restricts control over confounders, and future research could benefit from this approach to reduce variability.