An interventional study of Caffeinated Coffee and Decaffeinated Coffee Placebo in Cognitive Performance, Attention and Reaction Time, sponsored by St. Louis University. Recruiting at 1 site in United States. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-30.
Sponsored by St. Louis University · Not applicable, Interventional, and Basic science
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.
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.
175 studies on the registry are indexed under Mental Fatigue; 54 are open to participants now.
This study's planned enrollment of 12 is below the median of 45 across 143 interventional studies indexed under Mental Fatigue.
Browse Mental Fatigue studies →St. Louis University is the lead sponsor of 156 studies on the registry; 17 are open to participants now.
Of its 19 completed or terminated interventional studies of FDA-regulated products, 15 (79%) have results posted.
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Exclusion Criteria:
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Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Dietary Supplement: Caffeinated Coffee
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.
Dietary Supplement: Decaffeinated Coffee Placebo
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.
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.
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.
Time frame: 30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
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.
Plan to share: 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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