Athletic PerformanceCAFF-WRESTNCT07889661
Caffeine and Wrestling Performance in Male Wrestlers of Different Weight Classes: A Randomized Crossover Trial
A study testing Caffeine in people with Athletic Performance and Caffeine, run by Islamic Azad University, Abadan Branch at 1 site in Iran.
Trial summary
Caffeine is commonly used by athletes to improve performance, but not everyone responds to it in the same way. In weight-class sports like wrestling, athletes are grouped by body weight. Read more about this study
- Who is it for?
- Ages 15 to 40 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance, Caffeine, Wrestling
- What is being tested?
- Caffeine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 95 participants
- Where
- 1 siteIran
- Study dates
- 30 Mar 2026to 6 Jun 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 15 to 40 years
- Men only
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Male wrestlers aged 15 to 35 years.
- Competing in Greco-Roman or freestyle wrestling.
- At least four years of systematic wrestling training experience (for the parent trial) or at least three years of continuous wrestling training (for the secondary analysis).
- Competing consistently in a fixed Olympic weight category for at least the previous two years.
- Maintaining current body weight within 3 kg of competition weight.
- No competition or tournament participation within the last month before the study.
Show all 11Show fewer
- Regular participation in organized training (at least 3 sessions per week).
- Current involvement in freestyle or Greco-Roman wrestling at amateur, semi-professional, or professional level.
- Willing to provide written informed consent.
- Willing to abstain from caffeine-containing foods, beverages, and supplements for 24 hours before each testing session.
- Willing to avoid strenuous exercise for 24 hours before each testing session.
Who cannot join
- History of cardiovascular, metabolic, or neurological disorders.
- History of respiratory or gastrointestinal disease.
- Regular use of medication that could interfere with study outcomes.
- Current smoking or substance abuse.
- Injury or illness within the two weeks before the study.
- Injury limiting maximal exercise performance.
- Rapid weight reduction within the month before the study.
- Unwillingness to comply with study procedures or follow-up.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Investigating the Role of Weight Class, Skill Level, and Age on the Ergogenic Effects of Caffeine Consumption in Wrestlers
Caffeine is commonly used by athletes to improve performance, but not everyone responds to it in the same way. In weight-class sports like wrestling, athletes are grouped by body weight. When caffeine is dosed based on body weight (4 mg per kg), heavier athletes receive a larger total amount of caffeine than lighter athletes. This study asked whether the effects of caffeine on wrestling performance and side effects differ across wrestling weight classes.
Ninety-five male wrestlers (30 lightweight, 36 middleweight, and 29 heavyweight) completed two testing sessions: one after taking caffeine (4 mg/kg) and one after taking a placebo (an inactive capsule). Neither the wrestlers nor the researchers knew which capsule was given in each session. Each session included a countermovement jump test and a wrestling-specific fitness test that involved throwing a wrestling dummy. Heart rate, perceived exertion, and self-reported symptoms were also recorded.
Read more
The study found that lightweight and middleweight wrestlers generally performed better after caffeine, while heavyweight wrestlers showed no performance improvement and reported more side effects, such as anxiety, rapid heartbeat, stomach discomfort, and insomnia. These differences occurred even though all wrestlers received the same caffeine dose relative to their body weight.
The results suggest that a standard body-weight-based caffeine dose may not work equally well for all wrestlers. Lighter wrestlers may benefit more, while heavier wrestlers may experience more side effects without performance gains. These findings support the need for individualized caffeine dosing strategies in wrestling and similar weight-class sports. However, because body weight, total caffeine dose, and other weight-class-related factors were not separated in this study, the results should be considered exploratory and do not establish weight-specific recommendations.
- Conditions
- Athletic Performance, Caffeine, Wrestling
- Being tested
- Caffeine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CaffeineDrug
Anhydrous caffeine powder (Sigma-Aldrich, Steinheim, Germany) encapsulated in identical opaque gelatin capsules. Administered orally at a dose of 4 mg/kg body mass with approximately 200 mL of water, 60 minutes before performance testing.
| Study group | Role | What they receive |
|---|---|---|
| Caffeine then Placebo | Experimental | Participants in this arm received a caffeine capsule (4 mg/kg body mass) in the first experimental session and a placebo capsule (dextrose) in the second experimental session, with a 1-week washout period between sessions. Capsules were administered 60 minutes before performance testing. Participants completed countermovement jump testing and the Special Wrestling Fitness Test (SWFT) in each session. Receives: Drug: Caffeine |
| Placebo then Caffeine | Experimental | Participants in this arm received a placebo capsule (dextrose) in the first experimental session and a caffeine capsule (4 mg/kg body mass) in the second experimental session, with a 1-week washout period between sessions. Capsules were administered 60 minutes before performance testing. Participants completed countermovement jump testing and the Special Wrestling Fitness Test (SWFT) in each session. Receives: Drug: Caffeine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total number of throws (Tn)
Total number of successful throws completed across the three active periods of the Special Wrestling Fitness Test (SWFT). A throw was considered correct only when it satisfied the technical scoring criteria of United World Wrestling. Three independent assessors counted the throws, with discrepancies resolved through discussion.
Measured: Measured during each experimental session, 60 minutes after supplementation.
Performance Index (PI)
A wrestling-specific performance index calculated as (HR0 + HR1) / Tn, where HR0 is heart rate immediately after the SWFT and HR1 is heart rate 1 minute after the SWFT. A lower performance-index value indicates a greater number of throws relative to the recorded cardiac response.
Measured: Measured during each experimental session, 60 minutes after supplementation.
Secondary outcomes (5)
Body-mass-normalized throws (TnW)
Total number of throws normalized to body weight, calculated as Tn divided by body weight in kilograms (TnW = Tn / body weight). This outcome reflects wrestling-specific work relative to body weight and has shown strong predictive validity for wrestling performance.
Measured: Measured during each experimental session, 60 minutes after supplementation.
Countermovement jump performance
Lower-body explosive power assessed using the Sargent vertical jump test (wall-mounted reach method). Participants performed three maximal countermovement jumps with 60 s passive recovery between attempts. Jump height (cm) was calculated as the difference between standing reach and maximal jump reach. The highest value was retained for analysis.
Measured: 60 minutes after supplementation, before the Special Wrestling Fitness Test (SWFT).
Rating of perceived exertion (RPE)
Overall perceived exertion during the SWFT, assessed using the 10-point Borg scale immediately after the test.
Measured: Immediately after the SWFT.
Self-reported symptoms on the test day
Presence or absence of negative symptoms assessed using an adapted QUEST checklist: anxiety, headache, dizziness, nervousness, irritability, tachycardia, abdominal discomfort, increased urine output, muscle soreness, and fatigue. Each item recorded dichotomously (yes/no). Vigor/activeness was treated separately as a positive self-reported effect and excluded from the adverse-symptom composite.
Measured: Immediately after each testing session (test day).
Self-reported symptoms on the following day
Presence or absence of negative symptoms including insomnia, assessed 24 hours after each testing session using the same adapted QUEST checklist.
Measured: 24 hours after each testing session.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Oct 2026
- Study start30 Mar 2026
- Primary completion4 Jun 2026
- Study completion6 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Athletic PerformanceStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 95 participants (actual)
Sponsor and investigators
- Lead sponsor
- Islamic Azad University, Abadan Branch
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Raoof Negaresh, Science & Research Islamic Azad University Branch Khozestan
- Investigators
- Raoof Negaresh, PhD, Principal investigator, Farhangian University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07889661
- Sponsor's protocol ID
- IR.ABADANUMS.REC.1404.131
- Other IDs
- 04/766078
- Acronym
- CAFF-WREST
- Status last verified
- Oct 2026
- First submitted
- 16 Oct 2026
- Last updated
- 22 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 22 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Role of Weight Class, Skill Level, and Age on the Ergogenic Effects of Caffeine Consumption in Wrestlers
- ClinicalTrials.gov ID
- NCT07889661
- Acronym / sponsor ID
- CAFF-WREST / IR.ABADANUMS.REC.1404.131
- Conditions
- Athletic Performance, Caffeine, Wrestling
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 95 participants (actual)
- Lead sponsor
- Islamic Azad University, Abadan BranchUniversity, hospital or other
- Study start
- 30 Mar 2026 (actual)
- Primary completion
- 4 Jun 2026 (actual)
- Study completion
- 6 Jun 2026 (actual)
- First posted
- 22 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Caffeine is commonly used by athletes to improve performance, but not everyone responds to it in the same way. In weight-class sports like wrestling, athletes are grouped by body weight. When caffeine is dosed based on body weight (4 mg per kg), heavier athletes receive a larger total amount of caffeine than lighter athletes. This study asked whether the effects of caffeine on wrestling performance and side effects differ across wrestling weight classes.
Ninety-five male wrestlers (30 lightweight, 36 middleweight, and 29 heavyweight) completed two testing sessions: one after taking caffeine (4 mg/kg) and one after taking a placebo (an inactive capsule). Neither the wrestlers nor the researchers knew which capsule was given in each session. Each session included a countermovement jump test and a wrestling-specific fitness test that involved throwing a wrestling dummy. Heart rate, perceived exertion, and self-reported symptoms were also recorded.
The study found that lightweight and middleweight wrestlers generally performed better after caffeine, while heavyweight wrestlers showed no performance improvement and reported more side effects, such as anxiety, rapid heartbeat, stomach discomfort, and insomnia. These differences occurred even though all wrestlers received the same caffeine dose relative to their body weight.
The results suggest that a standard body-weight-based caffeine dose may not work equally well for all wrestlers. Lighter wrestlers may benefit more, while heavier wrestlers may experience more side effects without performance gains. These findings support the need for individualized caffeine dosing strategies in wrestling and similar weight-class sports. However, because body weight, total caffeine dose, and other weight-class-related factors were not separated in this study, the results should be considered exploratory and do not establish weight-specific recommendations.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Caffeine then Placebo | Experimental | Drug: CaffeineParticipants in this arm received a caffeine capsule (4 mg/kg body mass) in the first experimental session and a placebo capsule (dextrose) in the second experimental session, with a 1-week washout period between sessions. Capsules were administered 60 minutes before performance testing. Participants completed countermovement jump testing and the Special Wrestling Fitness Test (SWFT) in each session. |
| Placebo then Caffeine | Experimental | Drug: CaffeineParticipants in this arm received a placebo capsule (dextrose) in the first experimental session and a caffeine capsule (4 mg/kg body mass) in the second experimental session, with a 1-week washout period between sessions. Capsules were administered 60 minutes before performance testing. Participants completed countermovement jump testing and the Special Wrestling Fitness Test (SWFT) in each session. |
Who may qualify
- Ages
- 15 to 40 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (11 listed)
- Male wrestlers aged 15 to 35 years.
- Competing in Greco-Roman or freestyle wrestling.
- At least four years of systematic wrestling training experience (for the parent trial) or at least three years of continuous wrestling training (for the secondary analysis).
- Competing consistently in a fixed Olympic weight category for at least the previous two years.
- Maintaining current body weight within 3 kg of competition weight.
Key exclusion criteria (8 listed)
- History of cardiovascular, metabolic, or neurological disorders.
- History of respiratory or gastrointestinal disease.
- Regular use of medication that could interfere with study outcomes.
- Current smoking or substance abuse.
- Injury or illness within the two weeks before the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CaffeineAnhydrous caffeine powder (Sigma-Aldrich, Steinheim, Germany) encapsulated in identical opaque gelatin capsules. Administered orally at a dose of 4 mg/kg body mass with approximately 200 mL of water, 60 minutes before performance testing. | Drug | Caffeine then Placebo, Placebo then Caffeine |
Primary outcome
Total number of throws (Tn)
Time frame: Measured during each experimental session, 60 minutes after supplementation.
Total number of successful throws completed across the three active periods of the Special Wrestling Fitness Test (SWFT). A throw was considered correct only when it satisfied the technical scoring criteria of United World Wrestling. Three independent assessors counted the throws, with discrepancies resolved through discussion.
Performance Index (PI)
Time frame: Measured during each experimental session, 60 minutes after supplementation.
A wrestling-specific performance index calculated as (HR0 + HR1) / Tn, where HR0 is heart rate immediately after the SWFT and HR1 is heart rate 1 minute after the SWFT. A lower performance-index value indicates a greater number of throws relative to the recorded cardiac response.
5 secondary outcomes
Body-mass-normalized throws (TnW)
Time frame: Measured during each experimental session, 60 minutes after supplementation.
Countermovement jump performance
Time frame: 60 minutes after supplementation, before the Special Wrestling Fitness Test (SWFT).
Rating of perceived exertion (RPE)
Time frame: Immediately after the SWFT.
Self-reported symptoms on the test day
Time frame: Immediately after each testing session (test day).
Self-reported symptoms on the following day
Time frame: 24 hours after each testing session.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Oct 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Raoof Negaresh, PhD principal investigator
Farhangian University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Caffeine in people with Athletic Performance and Caffeine, run by Islamic Azad University, Abadan Branch at 1 site in Iran.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iran. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total number of throws (Tn) (time frame: Measured during each experimental session, 60 minutes after supplementation.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Oct 2026.