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Influence of caffeine, cold and exercise on multiple choice reaction time
B Kruk1, J Chmura, K Krzeminski
1Department of Applied Physiology, MRC, Polish Academy of Sciences, Warsaw. kruk@cmdik.pan.pl
Psychopharmacology
|October 12, 2001
Summary
Caffeine improved psychomotor reaction time during exercise in warm conditions but not in the cold. This suggests caffeine’s stimulating effects depend on arousal levels, influenced by environmental factors like temperature.
Area of Science:
- Exercise Physiology
- Sports Science
- Human Performance
Background:
- Caffeine's effects on psychomotor performance are known under resting, thermoneutral conditions.
- This study investigated if exercise and cold exposure modify caffeine's impact on alertness.
Purpose of the Study:
- To assess changes in multiple-choice reaction time (RT) during exercise.
- To compare effects of caffeine versus placebo at room and low temperatures.
Main Methods:
- Nine soccer players underwent incremental exercise to exhaustion.
- Caffeine or placebo was administered before exercise at 22°C and 4°C.
- Reaction time, blood lactate, oxygen uptake, and heart rate were measured.
Main Results:
- Caffeine significantly shortened RT during exercise at 22°C compared to placebo.
- No RT differences were observed between caffeine and placebo at 4°C.
- Cold exposure and caffeine did not affect maximal oxygen uptake, heart rate, or lactate threshold.
Conclusions:
- Caffeine enhances psychomotor performance during exercise in thermoneutral conditions.
- The ergogenic effect of caffeine on reaction time is diminished at low temperatures.
- Caffeine's effectiveness is modulated by arousal levels influenced by environmental conditions.