Athletic PerformanceNCT07562256
Effects of Different Doses of Caffeine on Physical and Cognitive Performance in Female Handball Players
A study testing Caffeine 3 mg/kg and Caffeine 6 mg/kg in people with Athletic Performance and Cognitive Performance, run by Sinop University at 1 site in Turkey (Türkiye).
Trial summary
This study investigates how different doses of caffeine affect physical and cognitive performance in female handball players. Caffeine is widely used as a performance-enhancing substance, but its effects may vary depending on the type of performance and the dose consumed. Read more about this study
- Who is it for?
- Ages 18 to 25 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance, Cognitive Performance, Healthy Adult Females
- What is being tested?
- Caffeine 3 mg/kg and Caffeine 6 mg/kg
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 25 Jan 2026to 20 Mar 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 18 to 25 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Female handball players
- Regular participation in competitive handball training
- Minimum of 3 years of handball training experience
- Free from musculoskeletal injury within the past 6 months
Who cannot join
- Known caffeine sensitivity or allergy
- Use of medications or supplements that may affect physical or cognitive performance
- Presence of cardiovascular disease
- Presence of metabolic disorders
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Dose-Dependent Effects of Acute Caffeine Ingestion on Physical and Cognitive Performance in Female Handball Players: A Randomized, Double-Blind, Placebo-Controlled Crossover Study
This study investigates how different doses of caffeine affect physical and cognitive performance in female handball players. Caffeine is widely used as a performance-enhancing substance, but its effects may vary depending on the type of performance and the dose consumed.
In this randomized, double-blind, placebo-controlled crossover study, participants complete three experimental conditions: placebo, low-dose caffeine (3 mg/kg), and moderate-dose caffeine (6 mg/kg). Each participant receives all conditions in a randomized order, with sufficient time between sessions to avoid carryover effects.
Read more
The study evaluates three main performance domains relevant to team sports. Physical performance is assessed using an intermittent running test. Cognitive performance is measured using a reaction time task that evaluates attention and inhibitory control. In addition, a throwing test is used to assess sport-specific motor performance.
The main objective is to determine whether caffeine produces dose-dependent improvements and whether these effects differ across physical, cognitive, and technical performance domains. The findings aim to provide practical insights for athletes and coaches regarding optimal caffeine use in team sport settings.
Read the detailed description
Caffeine is one of the most widely consumed ergogenic aids in sport, known to influence both physiological and cognitive processes primarily through antagonism of adenosine receptors. Although its beneficial effects on endurance performance and alertness are well established, evidence regarding its effects on cognitive control and sport-specific technical skills remains inconsistent, particularly in team sport settings where multiple performance domains interact.
Team sports such as handball require the integration of intermittent high-intensity physical efforts, rapid decision-making, and precise motor execution. These components are not independent; instead, they compete for shared neurocognitive resources, especially under conditions of fatigue. As a result, interventions such as caffeine supplementation may exert domain-specific effects rather than uniform improvements across all aspects of performance.
Despite extensive research on caffeine, most studies have examined either physical or cognitive outcomes in isolation. Furthermore, dose-response relationships remain unclear, with previous findings suggesting that lower doses may be sufficient to enhance physical performance, whereas cognitive outcomes may require higher levels of stimulation. However, limited evidence exists on whether these dose-dependent effects are maintained when multiple performance domains are assessed within the same experimental framework.
The present study addresses this gap by simultaneously evaluating physical, cognitive, and sport-specific motor performance following different doses of caffeine in female handball players. A randomized, double-blind, placebo-controlled crossover design is used to minimize inter-individual variability and improve internal validity. Participants complete three experimental conditions (placebo, low-dose caffeine, and moderate-dose caffeine), each separated by an adequate washout period to reduce potential carryover effects.
The protocol includes standardized procedures to control for confounding factors such as time of day, environmental conditions, and prior physical activity. Testing sessions follow a fixed sequence, beginning with cognitive assessment, followed by a sport-specific throwing task, and concluding with an intermittent running test. This structure is designed to reflect the multi-component demands of team sport performance while maintaining methodological control.
The primary objective is to determine whether caffeine produces dose-dependent effects across different performance domains. Specifically, the study examines whether physical performance improvements occur at lower doses, whether cognitive performance shows greater sensitivity to higher doses, and whether technical motor performance responds differently to caffeine ingestion. By integrating these domains within a single experimental design, the study aims to provide a more ecologically valid understanding of caffeine's ergogenic effects in team sport contexts.
The findings are expected to contribute to evidence-based recommendations for caffeine use in athletes, emphasizing the importance of aligning supplementation strategies with specific performance goals rather than assuming uniform benefits across all domains.
- Being tested
- Caffeine 3 mg/kg, Caffeine 6 mg/kg, Placebo
- Keywords
- Caffeine, Dose-response, Physical performance, Cognitive performance, Handball Players
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeine 3 mg/kgDietary supplement
Acute ingestion of caffeine at a dose of 3 mg per kilogram of body mass, administered in capsule form 60 minutes prior to testing.
Caffeine 6 mg/kgDietary supplement
Acute ingestion of caffeine at a dose of 6 mg per kilogram of body mass, administered in capsule form 60 minutes prior to testing.
PlaceboOther
Ingestion of identical capsules containing polydextrose with no active ingredient, administered 60 minutes prior to testing.
| Study group | Role | What they receive |
|---|---|---|
| Placebo Condition | Placebo comparator | Participants receive placebo capsules prior to testing in a randomized Receives: Other: Placebo |
| Low-Dose Caffeine | Experimental | Participants receive 3 mg/kg caffeine prior to testing in a randomized Receives: Dietary Supplement: Caffeine 3 mg/kg |
| Moderate-Dose Caffeine | Experimental | Participants receive 6 mg/kg caffeine prior to testing in a randomized Receives: Dietary Supplement: Caffeine 6 mg/kg |
What is being measured
The primary outcome is the main question the study is designed to answer.
Flanker Task Reaction Time
Mean reaction time (ms) during correct trials in the Simplified Eriksen Flanker task, used to assess cognitive processing speed.
Measured: During each experimental session (60 minutes after supplementation)
Yo-Yo Intermittent Recovery Test Level 1 Distance
Total distance covered during the Yo-Yo Intermittent Recovery Test Level 1, used to assess intermittent running performance.
Measured: During each experimental session (60 minutes after supplementation)
Throwing Velocity
Mean ball velocity (km/h) measured during a standardized handball throwing test.
Measured: During each experimental session (60 minutes after supplementation)
Secondary outcomes (2)
Flanker Task Accuracy
Percentage of correct responses in the Simplified Eriksen Flanker task.
Measured: During each experimental session (60 minutes after supplementation)
Flanker Effect
Difference in reaction time between incongruent and congruent trials in the Flanker task.
Measured: During each experimental session (60 minutes after supplementation)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 May 2026
- Study start25 Jan 2026
- Primary completion10 Mar 2026
- Study completion20 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sinop University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ulaş Can YILDIRIM, Sinop University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07562256
- Sponsor's protocol ID
- SU-2025-688-CAF
- Status last verified
- Apr 2026
- First submitted
- 24 Apr 2026
- Last updated
- 1 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: At the time of registration, a decision regarding sharing individual participant data (IPD) has not yet been finalized. The study dataset is currently being prepared for publication and institutional archiving. Future data sharing will be considered after publication, taking into account institutional policies, ethical approvals, and participant confidentiality requirements. If appropriate, de-identified data underlying the published results may be made available upon reasonable request.
Publications
Pickering C, Grgic J. Caffeine and Exercise: What Next? Sports Med. 2019 Jul;49(7):1007-1030. doi: 10.1007/s40279-019-01101-0.
PubMed 30977054McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine's effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016 Dec;71:294-312. doi: 10.1016/j.neubiorev.2016.09.001. Epub 2016 Sep 6.
PubMed 27612937Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4.
PubMed 33388079
Study at a glance
From the registry record, last updated by the sponsor on 1 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dose-Dependent Effects of Acute Caffeine Ingestion on Physical and Cognitive Performance in Female Handball Players: A Randomized, Double-Blind, Placebo-Controlled Crossover Study
- ClinicalTrials.gov ID
- NCT07562256
- Acronym / sponsor ID
- SU-2025-688-CAF
- Keywords
- Caffeine, Dose-response, Physical performance, Cognitive performance, Handball Players
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Sinop UniversityUniversity, hospital or other
- Study start
- 25 Jan 2026 (actual)
- Primary completion
- 10 Mar 2026 (actual)
- Study completion
- 20 Mar 2026 (actual)
- First posted
- 1 May 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.
This study investigates how different doses of caffeine affect physical and cognitive performance in female handball players. Caffeine is widely used as a performance-enhancing substance, but its effects may vary depending on the type of performance and the dose consumed.
In this randomized, double-blind, placebo-controlled crossover study, participants complete three experimental conditions: placebo, low-dose caffeine (3 mg/kg), and moderate-dose caffeine (6 mg/kg). Each participant receives all conditions in a randomized order, with sufficient time between sessions to avoid carryover effects.
The study evaluates three main performance domains relevant to team sports. Physical performance is assessed using an intermittent running test. Cognitive performance is measured using a reaction time task that evaluates attention and inhibitory control. In addition, a throwing test is used to assess sport-specific motor performance.
The main objective is to determine whether caffeine produces dose-dependent improvements and whether these effects differ across physical, cognitive, and technical performance domains. The findings aim to provide practical insights for athletes and coaches regarding optimal caffeine use in team sport settings.
Detailed description
Caffeine is one of the most widely consumed ergogenic aids in sport, known to influence both physiological and cognitive processes primarily through antagonism of adenosine receptors. Although its beneficial effects on endurance performance and alertness are well established, evidence regarding its effects on cognitive control and sport-specific technical skills remains inconsistent, particularly in team sport settings where multiple performance domains interact.
Team sports such as handball require the integration of intermittent high-intensity physical efforts, rapid decision-making, and precise motor execution. These components are not independent; instead, they compete for shared neurocognitive resources, especially under conditions of fatigue. As a result, interventions such as caffeine supplementation may exert domain-specific effects rather than uniform improvements across all aspects of performance.
Despite extensive research on caffeine, most studies have examined either physical or cognitive outcomes in isolation. Furthermore, dose-response relationships remain unclear, with previous findings suggesting that lower doses may be sufficient to enhance physical performance, whereas cognitive outcomes may require higher levels of stimulation. However, limited evidence exists on whether these dose-dependent effects are maintained when multiple performance domains are assessed within the same experimental framework.
The present study addresses this gap by simultaneously evaluating physical, cognitive, and sport-specific motor performance following different doses of caffeine in female handball players. A randomized, double-blind, placebo-controlled crossover design is used to minimize inter-individual variability and improve internal validity. Participants complete three experimental conditions (placebo, low-dose caffeine, and moderate-dose caffeine), each separated by an adequate washout period to reduce potential carryover effects.
The protocol includes standardized procedures to control for confounding factors such as time of day, environmental conditions, and prior physical activity. Testing sessions follow a fixed sequence, beginning with cognitive assessment, followed by a sport-specific throwing task, and concluding with an intermittent running test. This structure is designed to reflect the multi-component demands of team sport performance while maintaining methodological control.
The primary objective is to determine whether caffeine produces dose-dependent effects across different performance domains. Specifically, the study examines whether physical performance improvements occur at lower doses, whether cognitive performance shows greater sensitivity to higher doses, and whether technical motor performance responds differently to caffeine ingestion. By integrating these domains within a single experimental design, the study aims to provide a more ecologically valid understanding of caffeine's ergogenic effects in team sport contexts.
The findings are expected to contribute to evidence-based recommendations for caffeine use in athletes, emphasizing the importance of aligning supplementation strategies with specific performance goals rather than assuming uniform benefits across all domains.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Placebo Condition | Placebo comparator | Other: PlaceboParticipants receive placebo capsules prior to testing in a randomized |
| Low-Dose Caffeine | Experimental | Dietary Supplement: Caffeine 3 mg/kgParticipants receive 3 mg/kg caffeine prior to testing in a randomized |
| Moderate-Dose Caffeine | Experimental | Dietary Supplement: Caffeine 6 mg/kgParticipants receive 6 mg/kg caffeine prior to testing in a randomized |
Who may qualify
- Ages
- 18 to 25 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Female handball players
- Regular participation in competitive handball training
- Minimum of 3 years of handball training experience
- Free from musculoskeletal injury within the past 6 months
Key exclusion criteria (4 listed)
- Known caffeine sensitivity or allergy
- Use of medications or supplements that may affect physical or cognitive performance
- Presence of cardiovascular disease
- Presence of metabolic disorders
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 |
|---|---|---|
| Caffeine 3 mg/kgAcute ingestion of caffeine at a dose of 3 mg per kilogram of body mass, administered in capsule form 60 minutes prior to testing. | Dietary supplement | Low-Dose Caffeine |
| Caffeine 6 mg/kgAcute ingestion of caffeine at a dose of 6 mg per kilogram of body mass, administered in capsule form 60 minutes prior to testing. | Dietary supplement | Moderate-Dose Caffeine |
| PlaceboIngestion of identical capsules containing polydextrose with no active ingredient, administered 60 minutes prior to testing. | Other | Placebo Condition |
Primary outcome
Flanker Task Reaction Time
Time frame: During each experimental session (60 minutes after supplementation)
Mean reaction time (ms) during correct trials in the Simplified Eriksen Flanker task, used to assess cognitive processing speed.
Yo-Yo Intermittent Recovery Test Level 1 Distance
Time frame: During each experimental session (60 minutes after supplementation)
Total distance covered during the Yo-Yo Intermittent Recovery Test Level 1, used to assess intermittent running performance.
Throwing Velocity
Time frame: During each experimental session (60 minutes after supplementation)
Mean ball velocity (km/h) measured during a standardized handball throwing test.
2 secondary outcomes
Flanker Task Accuracy
Time frame: During each experimental session (60 minutes after supplementation)
Flanker Effect
Time frame: During each experimental session (60 minutes after supplementation)
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 1 May 2026.
- Background: PubMed 30977054Pickering C, Grgic J. Caffeine and Exercise: What Next? Sports Med. 2019 Jul;49(7):1007-1030. doi: 10.1007/s40279-019-01101-0.
- Background: PubMed 27612937McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine's effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016 Dec;71:294-312. doi: 10.1016/j.neubiorev.2016.09.001. Epub 2016 Sep 6.
- Background: PubMed 33388079Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4.
- Individual participant dataSharing planned: Undecided. At the time of registration, a decision regarding sharing individual participant data (IPD) has not yet been finalized. The study dataset is currently being prepared for publication and institutional archiving. Future data sharing will be considered after publication, taking into account institutional policies, ethical approvals, and participant confidentiality requirements. If appropriate, de-identified data underlying the published results may be made available upon reasonable request.
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 3 mg/kg and Caffeine 6 mg/kg in people with Athletic Performance and Cognitive Performance, run by Sinop 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 4 inclusion and 4 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 1 May 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?
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?
Flanker Task Reaction Time (time frame: During each experimental session (60 minutes after supplementation)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07562256, which also lists 3 linked publications.
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 1 May 2026.