The Impact of Caffeine on Reaction Times and Cognitive Processing in Athletes

Abstract

2.1.1 Background: Caffeine is the most popular drug consumed worldwide by athletes as an accepted ergogenic aid. There are numerous studies that debate caffeine's effect on an athlete's reaction times and cognitive function. It would be advantageous to determine its effect with so many athletes determined to improve their performance. 2.1.2 Objectives: To investigate the effect that caffeine has on an athlete's reaction time and cognitive function. Also to investigate the effect caffeine has on cardiovascular parameters of athletes and to investigate the difference caffeine has on males and females. 2.1.3 Design: Randomised, single blinded, crossover, placebo-controlled study with 26 participants. Subjects had their blood pressure measured and then ingested 250ml of sugar-free Red Bull containing 80mg of caffeine or 250ml of caffeine-free diet coke (placebo). 60 minutes later they had their blood pressure measured again and then carried out a reaction ruler test and a Stroop colour test. This was repeated with the alternative drink a week later. 2.1.4 Results: In comparison to the placebo, caffeine significantly improved reaction time (p=0.00067). For the Stroop test, caffeine significantly improved overall time (p=0.0012). However, it did not have any effect on the total number of errors (p=0.89). The results were similar when analysing males and females. Caffeine had no effect on athletes' cardiovascular parameters (systolic blood pressure p=0.63, diastolic blood pressure p=0.46, heart rate p=0.12). However, in the analysis of males and females, it significantly increased systolic blood pressure for both males (p=0.014) and females (p=0.012), but it did not increase diastolic blood pressure or heart rate. 2.1.5 Conclusion: In comparison to the placebo, 80mg of caffeine in the form of 250ml of sugar-free Red Bull significantly improved athletes' reaction times and indicated an improvement in their cognitive function. However, it did not affect their cardiovascular parameters. 2.1.6 Key words: caffeine, reaction time, cognitive function, cardiovascular parameters