Caffeine increases the cognitive speed and accuracy of collegiate athletes.
Background Caffeine has been shown to be an effective ergogenic aid and to enhance cognitive function and reaction times. Cognitive speed, accuracy and reaction times are very important to in-game performance, yet there is limited research demonstrating this effect in athletes. Caffeine has also been said to impact women and men differently, however research investigating a gender difference in athlete’s cardiovascular response to caffeine is also scarce. Objectives The aim was to investigate the effect of caffeine on the cognitive function, cardiovascular function and reaction times of collegiate athletes. Objectives were to determine the effect of caffeine on cognitive speed and accuracy, the impact caffeine has on cardiovascular function of athletes and whether response to caffeine is influenced by gender and sport (basketball or rugby) and to use a computerised program to assess the influence of caffeine on athlete reaction time. Method In this randomised, placebo-controlled, crossover study, blood pressure and heart rate along with baseline reaction time and cognitive function (using the Stroop test) of 25 volunteers (11 female) was measured. Subjects then received a caffeinated energy drink (Caffeine) or placebo (Control) and waited 45 minutes before repeating the testing protocol again. After 1 week, participants returned to repeat the protocol again, receiving the opposite drink. Results Cognitive speed improved in the Stroop test (125.3 seconds pre-caffeine to 115.1 seconds post-caffeine, 0.001≤p≤0.002). Cognitive accuracy during the Stroop test also improved (2.92 total errors pre-caffeine to 1.76 errors post-caffeine, p=0.001). Caffeine significantly increased systolic blood pressure (SBP) (p=0.03) but had no effect on heart rate (HR). Whereas Control decreased HR (p=0.03) but had no impact on SBP. There was no difference in response by gender or by sport and caffeine had no effect on reaction times. Discussion Cognitive speed and accuracy were significantly improved following caffeine supplementation in comparison to control. Caffeine significantly increased SBP, a result commonly expressed in previous literature. This was the first study to compare cardiovascular response to caffeine by gender and sport-type, however gender and sport-type had no significant influence. The results of this study suggest caffeine effectively enhances cognitive speed and accuracy of athletes, but will not influence their reaction times. Also, cardiovascular response to caffeine does not differ by gender or between basketball and rugby players. Key Words: Caffeine, Athlete, Stroop Test, Reaction Time, Blood Pressure, Cognitive Function