Dose-Response Effects of Short-Term Ashwagandha on Anaerobic Exercise and Cognitive Function in Resistance-Trained Athletes

NCT07853274 | Completed

• 2 other identifiers: JSU-EPNL-2026-0310000-30211-20
• Study Type: interventional
• Target: 23
• Locations: 1 country
• Sites: 1

Brief Summary

Ashwagandha (ASH) is an herbal supplement derived from the Withania somnifera plant. It is commonly described as an adaptogen, a substance thought to help the body cope with physical and psychological stress. Previous research has examined ashwagandha supplementation using different doses and supplementation periods. This study examined the effects of seven days of supplementation on muscular strength, exercise performance, cognitive function, and selected physiological measures in healthy, resistance-trained men and women. It also examined whether these effects differed between low and high doses. The study used a crossover design in which each participant completed four conditions: no supplementation, a placebo containing maltodextrin, low-dose ashwagandha at 4 mg per kilogram of body weight per day for seven days, and high-dose ashwagandha at 14 mg per kilogram of body weight per day for seven days. The three supplementation conditions were separated by seven-day washout periods. During the blinded supplementation conditions, neither the participants nor the researchers conducting the assessments knew which supplement was being administered. At the end of each seven-day supplementation period, participants completed laboratory assessments. These included the maximum weight lifted for one repetition on the bench press and leg press, total lifting volume across multiple sets, and the speed and power of bar movement. Participants also completed a 30-second all-out cycling sprint to assess anaerobic power, total work, and fatigue, along with a color-word test to assess cognitive performance. Additional assessments included resting energy expenditure, heart rate, blood pressure, perceived exertion, self-reported readiness, focus, alertness, and selected blood markers related to cholesterol, liver function, and muscle damage.

Conditions

Cognitive Functions; Anaerobic Performance; Dietary Supplementation Athletic Performance; Resistance Exercise Performance

Keywords

Ashwagandha; Anaerobic Exercise; Cognitive Function; Resistance Training; Dose-Response; Sports Nutrition; Placebo-Controlled

Outcome Measures

Primary Outcomes (2)

• Resistance Exercise Performance

  Outcome measures comprised bench press and leg press one-repetition maximum (1RM), total lifting volume (sets × reps × weight), and Tendo-derived peak and mean barbell power during the bench press. These variables were assessed at four time points within a crossover design incorporating a one-week supplementation phase and a one-week washout phase, with each outcome reported in its corresponding unit (kilograms for 1RM and volume; watts for power).

  Baseline and after each of three seven-day supplementation periods, with seven-day washouts between conditions; total duration approximately five weeks.

• Anaerobic Exercise Performance

  Peak power, mean power, and total work were measured via the 30-second Wingate Anaerobic Test. Assessed at 4 time points across a crossover design (1-week supplementation, 1-week washout). Each measure was reported separately in its respective unit (watts for peak and mean power; joules for total work).

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation)

Secondary Outcomes (6)

• Cognitive Function

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation).

• Rating of Perceived Exertion (RPE)

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation)

• Heart Rate (HR)

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation)

• Systolic Blood Pressure (SBP)

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation)

• Diastolic Blood Pressure (DBP)

  Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation)

Study Arms (4)

No-Capsule Control

NO INTERVENTION

No supplement was administered. Participants completed all testing procedures without receiving any substance.

Placebo

PLACEBO COMPARATOR

Participants received maltodextrin capsules matched in appearance to the blackcurrant supplement capsules.

Dietary Supplement: Maltodextrin (Placebo)

Low-dose Ashwagandha

EXPERIMENTAL

Participants received an ashwagandha supplement at 4 mg/kg/day.

Dietary Supplement: Low-dose Ashwagandha Supplement

High-Dose Rhodiola Ashwagandha

EXPERIMENTAL

Participants received an ashwagandha supplement at 14 mg/kg/day.

Dietary Supplement: High-dose Ashwagandha Supplement

Interventions

Low-dose Ashwagandha Supplement DIETARY_SUPPLEMENT

A low-dose ashwagandha supplement (4 mg/kg/day) was administered to assess its effects on anaerobic exercise performance and cognitive function.

Low-dose Ashwagandha

High-dose Ashwagandha Supplement DIETARY_SUPPLEMENT

A high-dose ashwagandha (14 mg/kg/day) supplement was administered to examine its effects on anaerobic exercise performance and cognitive function.

High-Dose Rhodiola Ashwagandha

Maltodextrin (Placebo) DIETARY_SUPPLEMENT

Maltodextrin capsules matched in appearance to the blackcurrant supplement capsules served as an inert placebo control.

Placebo

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-40 years
• At least 2 years of regular resistance training that included the bench press and either the leg press or squat
• Body mass index (BMI) of 18.5-24.9 kg/m²

You may not qualify if:

• Age under 18 years and above 40 yrs
• A history of treatment for metabolic disease (e.g., diabetes), hypertension, hypotension, thyroid disease, arrhythmias, and/or cardiovascular disease
• Current use of any prescription medication
• Intolerance to natural stimulants
• A history of smoking
• Excessive drinking (12 drinks per week)
• Known allergy to ashwagandha, as this could affect the participant's safety and the study's outcomes

Sponsors & Collaborators

• Jacksonville State University: lead

Study Sites (1)

Exercise Physiology and Nutrition Laboratory (EPNL) at Jacksonville State University

Jacksonville, Alabama, 36265-1724, United States

Location

MeSH Terms

Interventions

maltodextrin

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: The placebo, low-dose ashwagandha, and high-dose ashwagandha supplements were matched in total volume and weight to maintain blinding. Neither the participants nor the investigators conducting the assessments knew which supplement was being administered during the blinded conditions. The order of the three supplementation conditions was randomized and counterbalanced. The no-supplement control condition was not blinded and was used to establish baseline values.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 21, 2026
• First Posted: October 1, 2026
• Study Start: August 20, 2024
• Primary Completion: November 20, 2024
• Study Completion: January 25, 2025
• Last Updated: October 1, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: IPD and supporting information will be available beginning 6 months after publication and will remain available for a minimum of 5 years following the publication date."
• Access Criteria: Deidentified IPD will be made available to researchers who submit a methodologically sound request to the corresponding author. Requests should include the proposed use of the data, the research question, and the requester's institutional affiliation. Data will be shared in a standard format (e.g., Excel or SPSS) via secure file transfer.

Locations

US (1)