Acute Effects of a Glucose Energy Drink on Information Processing and Subjective Ratings of Stimulation

There has been a dramatic rise in the consumption of energy drinks (e.g., Red Bull, Monster, Amp) in the past decade, particularly among college students. Young people have become enamored with using these beverages to increase alertness, such as when studying. However, there has been little laboratory research to examine the acute effects of energy drinks on cognitive performance. The purpose of this study was to investigate the effects of a glucose energy drink on an information processing task and on subjective measures of stimulation and mental fatigue. Information processing was assessed using a psychological refractory period task that measured information processing when subjects were required to do two tasks at once. In this study, participants were randomly assigned to one of six dose conditions (energy drinks of 1.8 ml/kg, 3.6 ml/kg, 5.4 ml/kg, and 7.2 ml/kg, a decaffeinated placebo beverage and a no drink condition). Participants completed the cognitive task and subjective measures both at baseline and at 30 minutes after dose administration. The results indicated that the energy drink increased feelings of stimulation and decreased feelings of mental fatigue in a dose-dependent fashion. By contrast, the energy drink had no impact on information processing rates, as measured by the behavioral task. The results are consistent with a growing literature that the consumption of an energy drink may only benefit the subjective feeling state of the consumer, but has no impact on actual cognitive processing