Sports PerformanceTYCAF-BOXNCT07530185
Effects of L-Tyrosine and Caffeine on Performance in Elite Boxers
A study testing L-Tyrosine, Caffeine and L-tyrosine + Caffeine in people with Sports Performance, run by Inonu University at 1 site in Turkey (Türkiye).
Trial summary
Participants will complete six sessions, including one familiarization and baseline session followed by five experimental conditions: control (no supplementation), placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine. Read more about this study
- Who is it for?
- Ages 18 years and older, men onlyHealthy volunteers can take part
- Conditions the study is for
- Sports Performance
- What is being tested?
- L-Tyrosine, Caffeine and L-tyrosine + Caffeine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 18 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- Sep 2026to Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 years and older
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male elite boxers aged ≥18 years At least 8 years of boxing training experience Active participation in national or international competitions Regular training schedule No injury or illness affecting performance
Who cannot join
- Use of nutritional supplements or stimulants within the last 4 weeks Any cardiovascular, metabolic, or neurological disorder Current injury or musculoskeletal limitation Smoking or excessive caffeine intake Failure to comply with study procedures
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Ataturk University Faculty of Sport Sciences
Erzurum
Halil UÇAR, +90 5462921133, halil.ucar@inonu.edu.tr
About this study
Official title: Effects of L-Tyrosine and Caffeine Supplementation on Cognitive, Physical, and Physiological Parameters in Elite Boxers: A Randomized Double-Blind Placebo-Controlled Crossover Study
Participants will complete six sessions, including one familiarization and baseline session followed by five experimental conditions: control (no supplementation), placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine. The experimental conditions will be performed in a randomized, counterbalanced crossover design with a washout period of at least 72 hours between sessions. Resting physiological and cognitive assessments will be performed during the familiarization session, while biochemical, cognitive, and boxing-specific performance assessments will be conducted before and after each experimental session.
Read the detailed description
Participants will attend six sessions in total. The first session will be used for familiarization and baseline assessments, including anthropometric measurements, resting physiological measurements, and cognitive performance testing. The remaining five sessions will consist of one control condition (no supplementation) and four randomized experimental conditions (placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine) administered in a randomized, counterbalanced crossover design.
Each experimental session will be separated by a washout period of at least 72 hours. During the placebo, L-tyrosine, caffeine, and combined supplementation conditions, the assigned intervention will be administered 60 minutes before exercise. No supplement will be administered during the control condition.
Before and immediately after each experimental session, venous blood samples will be collected to assess brain-derived neurotrophic factor (BDNF) and oxidative stress biomarkers, including total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx). Cognitive performance will be evaluated using the computerized Stroop test, and boxing-specific physical performance will be assessed using a standardized boxing simulation protocol. Heart rate and rating of perceived exertion (RPE) will also be recorded during the exercise protocol.
- Conditions
- Sports Performance
- Being tested
- Placebo, L-Tyrosine, Caffeine, L-tyrosine + Caffeine
- Keywords
- L-tyrosine, Caffeine, Boxing, BDNF, Cognitive performance, Anaerobic performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboDietary supplement
Placebo solution matched in taste and volume to active supplements.
L-TyrosineDietary supplement
L-tyrosine at 150 mg/kg body weight administered 60 minutes before exercise.
CaffeineDietary supplement
Caffeine at 5 mg/kg body weight administered 60 minutes before exercise.
L-tyrosine + CaffeineDietary supplement
Combined L-tyrosine (150 mg/kg) and caffeine (5 mg/kg) administered 60 minutes before exercise.
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | Participants receive placebo condition. Receives: Dietary Supplement: Placebo |
| L-tyrosine | Experimental | Participants receive L-tyrosine condition. Receives: Dietary Supplement: L-Tyrosine |
| Caffeine | Experimental | Participants receive caffeine condition. Receives: Dietary Supplement: Caffeine |
| Combined | Experimental | Participants receive combined supplementation condition. Receives: Dietary Supplement: L-tyrosine + Caffeine |
| Control | No intervention | Participants complete the experimental protocol without receiving placebo or active supplementation. Baseline cognitive, physiological, and physical performance assessments are performed under the control condition. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Stroop Test Performance
Cognitive performance assessed using the Stroop test, including reaction time and accuracy.
Measured: up to 12 weeks
Secondary outcomes (2)
BDNF Levels
Serum brain-derived neurotrophic factor levels measured before and after exercise.
Measured: up to 12 weeks
Oxidative Stress Markers
Serum levels of total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA), superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity will be measured.
Measured: up to 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2026
- Study startSep 2026 (estimated)
- Primary completionDec 2026 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sports PerformanceStudies of the same condition, open and under way.
- More trials run by Inonu UniversityThe sponsor's other registered studies.
- 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will complete five experimental conditions (control, placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine) in a randomized, counterbalanced crossover design. Each experimental session will be separated by a washout period of at least 72 hours to minimize potential carryover effects.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 18 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Inonu University
- Sponsor type
- University, hospital or other
- Collaborators
- Ataturk University
- Responsible party
- Principal investigator, Halil UÇAR, Inonu University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07530185
- Sponsor's protocol ID
- UcarPhD2026
- Acronym
- TYCAF-BOX
- Status last verified
- Jul 2026
- First submitted
- 1 Apr 2026
- Last updated
- 8 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of L-Tyrosine and Caffeine Supplementation on Cognitive, Physical, and Physiological Parameters in Elite Boxers: A Randomized Double-Blind Placebo-Controlled Crossover Study
- ClinicalTrials.gov ID
- NCT07530185
- Acronym / sponsor ID
- TYCAF-BOX / UcarPhD2026
- Conditions
- Sports Performance
- Keywords
- L-tyrosine, Caffeine, Boxing, BDNF, Cognitive performance, Anaerobic performance
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 18 participants (estimated)
- Lead sponsor
- Inonu UniversityUniversity, hospital or other
- Collaborators
- Ataturk University
- Study start
- Sep 2026 (estimated)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 15 Apr 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.
Participants will complete six sessions, including one familiarization and baseline session followed by five experimental conditions: control (no supplementation), placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine. The experimental conditions will be performed in a randomized, counterbalanced crossover design with a washout period of at least 72 hours between sessions. Resting physiological and cognitive assessments will be performed during the familiarization session, while biochemical, cognitive, and boxing-specific performance assessments will be conducted before and after each experimental session.
Detailed description
Participants will attend six sessions in total. The first session will be used for familiarization and baseline assessments, including anthropometric measurements, resting physiological measurements, and cognitive performance testing. The remaining five sessions will consist of one control condition (no supplementation) and four randomized experimental conditions (placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine) administered in a randomized, counterbalanced crossover design.
Each experimental session will be separated by a washout period of at least 72 hours. During the placebo, L-tyrosine, caffeine, and combined supplementation conditions, the assigned intervention will be administered 60 minutes before exercise. No supplement will be administered during the control condition.
Before and immediately after each experimental session, venous blood samples will be collected to assess brain-derived neurotrophic factor (BDNF) and oxidative stress biomarkers, including total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx). Cognitive performance will be evaluated using the computerized Stroop test, and boxing-specific physical performance will be assessed using a standardized boxing simulation protocol. Heart rate and rating of perceived exertion (RPE) will also be recorded during the exercise protocol.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 5
- Model description
- Participants will complete five experimental conditions (control, placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine) in a randomized, counterbalanced crossover design. Each experimental session will be separated by a washout period of at least 72 hours to minimize potential carryover effects.
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Dietary Supplement: PlaceboParticipants receive placebo condition. |
| L-tyrosine | Experimental | Dietary Supplement: L-TyrosineParticipants receive L-tyrosine condition. |
| Caffeine | Experimental | Dietary Supplement: CaffeineParticipants receive caffeine condition. |
| Combined | Experimental | Dietary Supplement: L-tyrosine + CaffeineParticipants receive combined supplementation condition. |
| Control | No intervention | –Participants complete the experimental protocol without receiving placebo or active supplementation. Baseline cognitive, physiological, and physical performance assessments are performed under the control condition. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Male elite boxers aged ≥18 years At least 8 years of boxing training experience Active participation in national or international competitions Regular training schedule No injury or illness affecting performance
Key exclusion criteria (1 listed)
- Use of nutritional supplements or stimulants within the last 4 weeks Any cardiovascular, metabolic, or neurological disorder Current injury or musculoskeletal limitation Smoking or excessive caffeine intake Failure to comply with study procedures
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 |
|---|---|---|
| PlaceboPlacebo solution matched in taste and volume to active supplements. | Dietary supplement | Placebo |
| L-TyrosineL-tyrosine at 150 mg/kg body weight administered 60 minutes before exercise. | Dietary supplement | L-tyrosine |
| CaffeineCaffeine at 5 mg/kg body weight administered 60 minutes before exercise. | Dietary supplement | Caffeine |
| L-tyrosine + CaffeineCombined L-tyrosine (150 mg/kg) and caffeine (5 mg/kg) administered 60 minutes before exercise. | Dietary supplement | Combined |
Primary outcome
Stroop Test Performance
Time frame: up to 12 weeks
Cognitive performance assessed using the Stroop test, including reaction time and accuracy.
2 secondary outcomes
BDNF Levels
Time frame: up to 12 weeks
Oxidative Stress Markers
Time frame: up to 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jul 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing L-Tyrosine, Caffeine and L-tyrosine + Caffeine in people with Sports Performance, run by Inonu University at 1 site in Turkey (Türkiye).
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 1 inclusion and 1 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: opening soon, as of the sponsor's last update on 8 Jul 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 Turkey (Türkiye). 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. Some participants in this study may receive a placebo. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Halil UÇAR (+90 5462921133, halil.ucar@inonu.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Stroop Test Performance (time frame: up to 12 weeks). 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 8 Jul 2026.