Recruiting

CaffeineEffects of Caffeine on Chess Performance and Cognitive Function in Professional Chess Players

Sponsor:

St. Louis University

Code:

NCT07641335

Conditions

Cognitive Performance

Attention

Reaction Time

Caffeine

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Interventions

Caffeinated Coffee

Decaffeinated Coffee Placebo

Study Details

Brief 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 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.

Conditions

Cognitive Performance

Attention

Reaction Time

Caffeine

Study ID

NCT07641335

Start date

Aug 25, 2026

Status verified date

Jun, 2026

Completion date

Aug 30, 2027

Anticipated

Primary completion date

Jul 30, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

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

Exclusion Criteria:

Non-caffeine users
Habitual caffeine intake exceeding 2 cups of coffee per day
Cardiovascular disorders
Metabolic disorders
Psychiatric disorders
Pregnancy or breastfeeding
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

Study Design

Enrollment

12 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

active comparator: Caffeinated Coffee

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.

placebo comparator: Decaffeinated Coffee Placebo

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.

Interventions

Caffeinated Coffee

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 Placebo

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.

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. ]

Central Contacts and Locations

Central contacts

Hossein Rafiei, PhD

13149778675 hossein.rafiei@health.slu.edu

Locations

Saint Louis University

Recruiting

St Louis, Missouri, United States, 63104

Contacts

Hossein Rafiei, PhD

314-977-8675 hossein.rafiei@health.slu.edu

Principal Investigator:

Hossein Rafiei, PhD

More Information

Sponsor

St. Louis University

Last update posted

Sep 30, 2026

Last verified

Jun, 2026

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-01. This information was provided to ClinicalTrials.gov by St. Louis University on 2026-09-30. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.