Sports Performance
Conditions
Keywords
L-tyrosine, Caffeine, Boxing, BDNF, Cognitive performance, Anaerobic performance
Brief summary
Participants will complete five sessions, including one familiarization and baseline session and four experimental conditions (placebo, L-tyrosine, caffeine, and combined supplementation). The baseline session will include resting measurements. The experimental conditions will be performed in a randomized, counterbalanced crossover design with a washout period of at least 72 hours between sessions.
Detailed description
Participants will attend five sessions in total. The first session will be used for familiarization and baseline measurements, including resting physiological and cognitive assessments. The remaining four sessions will consist of randomized experimental conditions (placebo, L-tyrosine, caffeine, and combined supplementation), applied in a counterbalanced crossover design. Each experimental session will be separated by a washout period of at least 72 hours. Supplements will be administered 60 minutes before exercise. Cognitive performance will be assessed using the Stroop test, and physical performance will be evaluated using a boxing-specific simulation protocol. Physiological responses, including heart rate and biochemical markers such as BDNF and oxidative stress parameters, will be measured.
Interventions
DIETARY_SUPPLEMENTPlacebo
Placebo solution matched in taste and volume to active supplements.
DIETARY_SUPPLEMENTL-Tyrosine
L-tyrosine at 150 mg/kg body weight administered 60 minutes before exercise.
DIETARY_SUPPLEMENTCaffeine
Caffeine at 5 mg/kg body weight administered 60 minutes before exercise.
DIETARY_SUPPLEMENTL-tyrosine + Caffeine
Combined L-tyrosine (150 mg/kg) and caffeine (5 mg/kg) administered 60 minutes before exercise.
Sponsors
Inonu University
Ataturk University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Both participants and investigators are blinded to the supplementation conditions. Supplements are prepared and coded by an independent researcher to ensure double-blind conditions.
Intervention model description
Participants will complete four experimental conditions (placebo, L-tyrosine, caffeine, and combined supplementation) in a randomized, counterbalanced crossover design with a washout period of at least 72 hours between sessions.
Eligibility
Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
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
Exclusion criteria
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Stroop Test Performance | up to 12 weeks | Cognitive performance assessed using the Stroop test, including reaction time and accuracy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| BDNF Levels | up to 12 weeks | Serum brain-derived neurotrophic factor levels measured before and after exercise. |
| Oxidative Stress Markers | up to 12 weeks | 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. |
Countries
Turkey (Türkiye)
Contacts
CONTACTHalil UÇAR
Outcome results
None listed