Cognitive PerformanceGRANDMASTERNCT07641335
Effects of Caffeine on Chess Performance and Cognitive Function in Professional Chess Players
A study testing Caffeinated Coffee in people with Cognitive Performance and Attention, run by St. Louis University at 1 site in United States.
Trial summary
This study will examine whether caffeine improves cognitive and competitive performance in professional chess players during tournament-style games. In a randomized double-blind crossover design, participants will complete two experimental sessions in which they consume either caffeinated coffee or decaffeinated… Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Cognitive Performance, Attention, Reaction Time
- What is being tested?
- Caffeinated Coffee
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Aug 2026to 30 Aug 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 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male and female professional chess players aged 18-50 years
- Current Fédération Internationale des Échecs (FIDE) standard rating between 2300 and 2600 Elo, or achievement of a standard FIDE rating within this range during the previous 12 months
- Habitual caffeine consumers consuming ≤2 cups of coffee per day
- Willingness to comply with all study procedures and study visits
- Ability to provide written informed consent
Who cannot join
- Non-caffeine users
- Habitual caffeine intake exceeding 2 cups of coffee per day
- Cardiovascular disorders
- Metabolic disorders
- Psychiatric disorders
- Pregnancy or breastfeeding
Show all 12Show fewer
- Current smoking
- Shift workers
- Use of psychoactive medications
- Participation in another clinical trial within the previous 3 months
- Known allergy or intolerance to milk proteins, dairy products, or soy
- Known red-green color blindness or other color vision deficiencies that may interfere with Stroop Test performance
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Saint Louis University
St Louis, Missouri, 63104
Hossein Rafiei, PhD, 314-977-8675, hossein.rafiei@health.slu.edu
Hossein Rafiei, PhD
About this study
Official title: GRANDMASTER: Gauging the Role of Alertness and Neurostimulation With Dietary Caffeine in Master-Level Chess; A Double-Blind Randomized Crossover Trial
This study will examine whether caffeine improves cognitive and competitive performance in professional chess players during tournament-style games. In a randomized double-blind crossover design, participants will complete two experimental sessions in which they consume either caffeinated coffee or decaffeinated coffee before playing a standardized chess match. Cognitive performance will be assessed using attention and reaction-time tests, including the Stroop Test, Trail Making Test, and Puzzle Rush task. Chess performance outcomes such as move accuracy, time management, and error rates will also be evaluated. The study aims to determine whether moderate caffeine intake enhances focus, alertness, and decision-making during prolonged competitive chess play.
Read the detailed description
This randomized double-blind crossover trial will evaluate the effects of moderate caffeine intake on cognitive and competitive performance in professional chess players. Twelve FIDE-rated chess players will complete two experimental conditions in randomized order: caffeinated coffee and decaffeinated coffee placebo. During each visit, participants will complete standardized cognitive assessments and a tournament-style chess game under controlled laboratory conditions.
Primary outcomes will include objective chess performance metrics derived from chess engine analysis, including move accuracy, centipawn loss, error rates, and time management. Secondary outcomes will include cognitive test performance, tactical reaction time, and self-reported alertness and fatigue. Chess games will be analyzed using standardized software-based evaluation methods.
The crossover design allows each participant to serve as their own control, minimizing variability related to individual differences in skill level, caffeine tolerance, and playing style. The study aims to determine whether caffeine enhances sustained attention, decision-making, and competitive chess performance during prolonged gameplay. Findings may provide insight into nutritional strategies for cognitive performance optimization in mentally demanding competitive environments.
- Conditions
- Cognitive Performance, Attention, Reaction Time, Caffeine
- Being tested
- Caffeinated Coffee, Decaffeinated Coffee Placebo
- Keywords
- Caffeine, Chess Performance, Cognitive Performance, Attention, Mental Fatigue, Professional Chess Players, Decision Making, Neurocognitive Performance, Randomized Crossover Trial, Coffee, Alertness, Executive Function, Cognitive Fatigue
- Medical subject headings
- Mental Fatigue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeinated CoffeeDietary supplement
Black caffeinated coffee prepared from 15 g of ground coffee brewed in 200 g of water, providing approximately 100 mg of caffeine. The beverage will be consumed approximately 30 minutes before cognitive testing and tournament-style chess gameplay.
Decaffeinated Coffee PlaceboDietary supplement
Black decaffeinated coffee prepared from the same batch of coffee beans and matched for taste and appearance to the caffeinated condition. The beverage will be consumed approximately 30 minutes before cognitive testing and tournament-style chess gameplay.
| Study group | Role | What they receive |
|---|---|---|
| Caffeinated Coffee | Active comparator | Participants will consume one serving of black caffeinated coffee prepared from 15 g of ground coffee brewed in 200 g of water, providing approximately 100 mg of caffeine. The beverage will be consumed approximately 30 minutes before completion of cognitive testing and a standardized tournament-style chess game during the experimental visit. Receives: Dietary Supplement: Caffeinated Coffee |
| Decaffeinated Coffee Placebo | Placebo comparator | Participants will consume one serving of black decaffeinated coffee prepared to match the caffeinated coffee in taste and appearance. The beverage will be consumed approximately 30 minutes before completion of cognitive testing and a standardized tournament-style chess game during the experimental visit. Receives: Dietary Supplement: Decaffeinated Coffee Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Chess Performance Accuracy
Chess performance accuracy will be assessed using engine-based analysis of tournament-style chess games. The primary reported metric will be average centipawn loss per move, with lower values indicating better chess performance accuracy.
Measured: 30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.
Secondary outcomes (7)
Puzzle Rush Correct Responses
Tactical accuracy will be assessed using the 3-minute Puzzle Rush task on Chess.com. The outcome will be the total number of correctly solved tactical puzzles, with higher scores indicating better tactical accuracy.
Measured: Approximately 30 minutes after beverage consumption at each experimental visit.
Puzzle Rush Response Speed
Response speed will be assessed using the 3-minute Puzzle Rush task on Chess.com. The outcome will be average response time per puzzle, with lower values indicating faster response speed.
Measured: Approximately 30 minutes after beverage consumption at each experimental visit.
Stroop Test Performance
Selective attention will be assessed using the Stroop Test. The outcome will be the change in Stroop Test completion time from before gameplay to immediately after gameplay, with lower completion time indicating better performance.
Measured: Before gameplay and immediately after gameplay at each experimental visit.
Trail Making Test Performance
Cognitive flexibility and processing speed will be assessed using the Trail Making Test. The outcome will be the change in Trail Making Test completion time from before gameplay to immediately after gameplay, with lower completion time indicating better performance.
Measured: Before gameplay and immediately after gameplay at each experimental visit.
Self-Reported Alertness
Self-reported alertness will be assessed using a study-specific visual analog questionnaire. Higher scores will indicate greater perceived alertness.
Measured: Pre-game and immediately post-game at each experimental visit.
Self-Reported Mental Fatigue
Self-reported mental fatigue will be assessed using a study-specific visual analog questionnaire. Higher scores will indicate greater perceived mental fatigue.
Measured: Pre-game and immediately post-game at each experimental visit.
Average Time Per Move
Chess time management will be assessed as the average time used per move during each tournament-style chess game. This value will be calculated from the total game time divided by the number of moves completed by the participant.
Measured: From the start of the tournament-style chess game until game completion, assessed over approximately 3 to 4 hours at each experimental visit.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2026
- Study start25 Aug 2026
- Primary completion30 Jul 2027 (estimated)
- Study completion30 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cognitive 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
- Model description
- Participants will complete both intervention conditions in randomized order, including caffeinated coffee and decaffeinated coffee placebo. Each participant will serve as their own control in this double-blind crossover design. Experimental visits will be separated by a 3- to 7-day washout period to minimize potential carryover effects between conditions. During each visit, participants will complete standardized cognitive assessments and one tournament-style chess game under controlled laboratory conditions.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- St. Louis University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Hossein Rafiei, St. Louis University
- Investigators
- Hossein Rafiei, PhD, Principal investigator, St. Louis University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07641335
- Sponsor's protocol ID
- SLU-CHESS-CAFF-2026
- Acronym
- GRANDMASTER
- Status last verified
- Jun 2026
- First submitted
- 24 May 2026
- Last updated
- 30 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be publicly shared because this is a small pilot study involving highly specialized professional chess players, and there is potential risk of participant identification despite de-identification procedures.
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- GRANDMASTER: Gauging the Role of Alertness and Neurostimulation With Dietary Caffeine in Master-Level Chess; A Double-Blind Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT07641335
- Acronym / sponsor ID
- GRANDMASTER / SLU-CHESS-CAFF-2026
- Conditions
- Cognitive Performance, Attention, Reaction Time, Caffeine
- Keywords
- Caffeine, Chess Performance, Cognitive Performance, Attention, Mental Fatigue, Professional Chess Players, Decision Making, Neurocognitive Performance
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- St. Louis UniversityUniversity, hospital or other
- Study start
- 25 Aug 2026 (actual)
- Primary completion
- 30 Jul 2027 (estimated)
- Study completion
- 30 Aug 2027 (estimated)
- First posted
- 11 Jun 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 will examine whether caffeine improves cognitive and competitive performance in professional chess players during tournament-style games. In a randomized double-blind crossover design, participants will complete two experimental sessions in which they consume either caffeinated coffee or decaffeinated coffee before playing a standardized chess match. Cognitive performance will be assessed using attention and reaction-time tests, including the Stroop Test, Trail Making Test, and Puzzle Rush task. Chess performance outcomes such as move accuracy, time management, and error rates will also be evaluated. The study aims to determine whether moderate caffeine intake enhances focus, alertness, and decision-making during prolonged competitive chess play.
Detailed description
This randomized double-blind crossover trial will evaluate the effects of moderate caffeine intake on cognitive and competitive performance in professional chess players. Twelve FIDE-rated chess players will complete two experimental conditions in randomized order: caffeinated coffee and decaffeinated coffee placebo. During each visit, participants will complete standardized cognitive assessments and a tournament-style chess game under controlled laboratory conditions.
Primary outcomes will include objective chess performance metrics derived from chess engine analysis, including move accuracy, centipawn loss, error rates, and time management. Secondary outcomes will include cognitive test performance, tactical reaction time, and self-reported alertness and fatigue. Chess games will be analyzed using standardized software-based evaluation methods.
The crossover design allows each participant to serve as their own control, minimizing variability related to individual differences in skill level, caffeine tolerance, and playing style. The study aims to determine whether caffeine enhances sustained attention, decision-making, and competitive chess performance during prolonged gameplay. Findings may provide insight into nutritional strategies for cognitive performance optimization in mentally demanding competitive environments.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will complete both intervention conditions in randomized order, including caffeinated coffee and decaffeinated coffee placebo. Each participant will serve as their own control in this double-blind crossover design. Experimental visits will be separated by a 3- to 7-day washout period to minimize potential carryover effects between conditions. During each visit, participants will complete standardized cognitive assessments and one tournament-style chess game under controlled laboratory conditions.
| Arm | Type | Receives |
|---|---|---|
| Caffeinated Coffee | Active comparator | Dietary Supplement: Caffeinated CoffeeParticipants will consume one serving of black caffeinated coffee prepared from 15 g of ground coffee brewed in 200 g of water, providing approximately 100 mg of caffeine. The beverage will be consumed approximately 30 minutes before completion of cognitive testing and a standardized tournament-style chess game during the experimental visit. |
| Decaffeinated Coffee Placebo | Placebo comparator | Dietary Supplement: Decaffeinated Coffee PlaceboParticipants will consume one serving of black decaffeinated coffee prepared to match the caffeinated coffee in taste and appearance. The beverage will be consumed approximately 30 minutes before completion of cognitive testing and a standardized tournament-style chess game during the experimental visit. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Male and female professional chess players aged 18-50 years
- Current Fédération Internationale des Échecs (FIDE) standard rating between 2300 and 2600 Elo, or achievement of a standard FIDE rating within this range during the previous 12 months
- Habitual caffeine consumers consuming ≤2 cups of coffee per day
- Willingness to comply with all study procedures and study visits
- Ability to provide written informed consent
Key exclusion criteria (12 listed)
- Non-caffeine users
- Habitual caffeine intake exceeding 2 cups of coffee per day
- Cardiovascular disorders
- Metabolic disorders
- Psychiatric 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 |
|---|---|---|
| Caffeinated CoffeeBlack caffeinated coffee prepared from 15 g of ground coffee brewed in 200 g of water, providing approximately 100 mg of caffeine. The beverage will be consumed approximately 30 minutes before cognitive testing and tournament-style chess gameplay. | Dietary supplement | Caffeinated Coffee |
| Decaffeinated Coffee PlaceboBlack decaffeinated coffee prepared from the same batch of coffee beans and matched for taste and appearance to the caffeinated condition. The beverage will be consumed approximately 30 minutes before cognitive testing and tournament-style chess gameplay. | Dietary supplement | Decaffeinated Coffee Placebo |
Primary outcome
Chess Performance Accuracy
Time frame: 30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.
Chess performance accuracy will be assessed using engine-based analysis of tournament-style chess games. The primary reported metric will be average centipawn loss per move, with lower values indicating better chess performance accuracy.
7 secondary outcomes
Puzzle Rush Correct Responses
Time frame: Approximately 30 minutes after beverage consumption at each experimental visit.
Puzzle Rush Response Speed
Time frame: Approximately 30 minutes after beverage consumption at each experimental visit.
Stroop Test Performance
Time frame: Before gameplay and immediately after gameplay at each experimental visit.
Trail Making Test Performance
Time frame: Before gameplay and immediately after gameplay at each experimental visit.
Self-Reported Alertness
Time frame: Pre-game and immediately post-game at each experimental visit.
Self-Reported Mental Fatigue
Time frame: Pre-game and immediately post-game at each experimental visit.
Average Time Per Move
Time frame: From the start of the tournament-style chess game until game completion, assessed over approximately 3 to 4 hours at each experimental visit.
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 30 Sep 2026.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be publicly shared because this is a small pilot study involving highly specialized professional chess players, and there is potential risk of participant identification despite de-identification procedures.
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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.
Hossein Rafiei, PhD principal investigator
St. Louis 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 Caffeinated Coffee in people with Cognitive Performance and Attention, run by St. Louis University at 1 site in United States.
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 5 inclusion and 12 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: looking for participants now, as of the sponsor's last update on 30 Sep 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 United States. 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 Hossein Rafiei, PhD (13149778675, hossein.rafiei@health.slu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Chess Performance Accuracy (time frame: 30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.). 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 30 Sep 2026.