Author(s): MORI, S., WAKIMOTO, T., Institution: KAWASAKI UNIVERSITY OF MEDICAL WELFARE　, Country: JAPAN, Abstract-ID: 1838

INTRODUCTION:
This study examined the effects of consuming a caffeinated carbohydrate-containing energy drink, a non-caffeinated beverage, or water on exercise performance, perceived exertion, and cognitive function during and after intermittent high-intensity exercise simulating soccer match play. Performance in ball sports depends not only on physical capacity but also on cognitive processes such as rapid decision-making and attentional control. Although energy drink consumption is widespread among athletes, the acute effects of beverage components on cognitive function during and immediately after exercise remain unclear.
METHODS:
Ten healthy men and women with regular exercise habits participated in a randomized crossover design with three experimental conditions: water, a caffeinated carbohydrate-containing energy drink, and a non-caffeinated beverage. Participants completed an intermittent high-intensity cycling protocol using a cycle ergometer designed to replicate soccer-specific activity patterns. Each set consisted of 5 s at 50% of maximal anaerobic power followed by 25 s at 10% (30 s total). Ten sets constituted one block, and three blocks were performed. A 60-s rest interval separated the first and second blocks, while a 5-min low-intensity bout (10% maximal anaerobic power) was completed between the second and third blocks, during which a computerized Stroop Color–Word Test was administered. Cognitive performance was assessed before ingestion, 35 min post-ingestion, during exercise, and immediately post-exercise. Heart rate, mean power output, and rating of perceived exertion (RPE) were recorded as indices of physiological and perceptual responses.
RESULTS:
No significant differences among beverage conditions were observed for mean heart rate, mean power output, or RPE (all p > 0.05). Similarly, no significant beverage × time interaction was detected for cognitive performance, indicating limited effects of caffeine and carbohydrate intake. In contrast, a significant main effect of time was found, with response times in both Stroop and reverse Stroop tasks significantly shortened immediately after exercise, irrespective of beverage condition (p < 0.001).
CONCLUSION:
These findings suggest that intermittent high-intensity exercise itself, rather than energy drink consumption, enhances cognitive performance. Acute improvements in attention and information processing may result from exercise-induced activation of the central nervous system. Such effects may have practical implications for training design and performance optimization in competitive team sports.