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

Official title

GRANDMASTER: Gauging the Role of Alertness and Neurostimulation With Dietary Caffeine in Master-Level Chess; A Double-Blind Randomized Crossover Trial

Overview

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.

Interventions

• Dietary supplement 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.
• Dietary supplement 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 measures

• Chess Performance Accuracy [Time frame: 30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.]

Secondary outcome measures (7)

• 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.]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Triple blind

Primary purpose

Basic science

Study locations

United States · 1 center

• Saint Louis University — St Louis

Identifiers

NCT: NCT07641335 · SLU-CHESS-CAFF-2026

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗