Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study

Area of Science:

• Sports Science
• Human Performance
• Nutritional Science

Background:

• Caffeine is widely believed to enhance athletic performance.
• The psychological impact of perceived ergogenic effects requires further investigation.

Purpose of the Study:

• To investigate if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and 10km running performance.
• To determine if perceived caffeine effects interact with actual physiological responses.

Main Methods:

• Twenty-nine healthy participants completed two trials, receiving either a low (100mg) or high (300mg) dose of sham caffeine.
• Participants self-reported beliefs and experience with caffeine for performance enhancement.
• Choice reaction time (Ex-Gaussian analysis) and 10km run times were measured post-ingestion.

Main Results:

• Sham caffeine dose did not significantly alter CRT latency (p > 0.05).
• Running performance (10km time) was not affected by sham caffeine dose (p = 0.979).
• Neither belief nor belief combined with experience influenced CRT or running performance.

Conclusions:

• A dose-response relationship to sham caffeine was not observed in cognitive or endurance tasks.
• Perceived ergogenic effects of caffeine do not appear to influence objective performance measures in healthy individuals.
• Individual beliefs about caffeine do not mediate its physiological impact on performance.