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

NCT07641335 | Not Yet Recruiting

• 1 other identifier: SLU-CHESS-CAFF-2026
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

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

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

Outcome Measures

Primary Outcomes (1)

• 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.

  30 minutes after beverage consumption through completion of the tournament-style chess game at each experimental visit.

Secondary Outcomes (7)

• Puzzle Rush Correct Responses

  Approximately 30 minutes after beverage consumption at each experimental visit.

• Puzzle Rush Response Speed

  Approximately 30 minutes after beverage consumption at each experimental visit.

• Stroop Test Performance

  Before gameplay and immediately after gameplay at each experimental visit.

• Trail Making Test Performance

  Before gameplay and immediately after gameplay at each experimental visit.

• Self-Reported Alertness

  Pre-game and immediately post-game at each experimental visit.

Study Arms (2)

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.

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.

Dietary Supplement: Decaffeinated Coffee Placebo

Interventions

Caffeinated Coffee DIETARY_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.

Caffeinated Coffee

Decaffeinated Coffee Placebo DIETARY_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.

Decaffeinated Coffee Placebo

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• St. Louis University: lead

Study Sites (1)

Saint Louis University

St Louis, Missouri, 63104, United States

Location

MeSH Terms

Conditions

Mental Fatigue

Condition Hierarchy (Ancestors)

Fatigue; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavioral Symptoms; Behavior

Study Officials

• Hossein Rafiei, PhD

  St. Louis University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Hossein Rafiei, PhD

CONTACT

13149778675; hossein.rafiei@health.slu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The caffeinated and decaffeinated coffee beverages will be prepared and coded by a designated research team member who is not involved in participant testing, cognitive assessments, gameplay supervision, or outcome analysis. Participants, investigators, and outcome assessors will remain blinded to intervention assignment until completion of data analysis.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: 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.

Study Record Dates

• First Submitted: May 24, 2026
• First Posted: June 11, 2026
• Study Start: June 15, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: June 11, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)