Caffeine Improves Physical and Cognitive Performance during Exhaustive Exercise

HOGERVORST, E., S. BANDELOW, J. SCHMITT, R. JENTJENS, M. OLIVEIRA, J. ALLGROVE, T. CARTER, and M. GLEESON. Caffeine Improves Physical and Cognitive Performance during Exhaustive Exercise. Med. Sci. Sports Exerc., Vol. 40, No. 10, pp. 1841-1851, 2008. Caffeine is thought to act as a central stimulant and to have effects oil physical, cognitive, and psychomotor functioning. Purpose: To examine the effects of ingesting a performance bar, containing caffeine, before and during cycling exercise oil physical and cognitive performance. Methods: Twenty-four well-trained cyclists consumed the products [a performance bar containing 45 g of carbohydrate and 100 mg of caffeine (CAF), all isocaloric noncaffeine performance bar (CHO), or 300 nit, of placebo beverage (BEV)] immediately before performing a 2.5-h exercise at 60% (V)over dotO(2max) followed by a time to exhaustion trial (T2EX) at 75% (V)over dotO(2max). Additional products were taken after 55 and 115 min of exercise. Cognitive function measures (computerized Stroop and Rapid Visual Information Processing tests) were performed before exercise and while cycling after 70 and 140 min of exercise and again 5 min after completing the T2EX ride. Results: Participants were significantly faster after CAF when compared with CHO on both the computerized complex information processing tests, particularly after 140 min and after the T2EX ride (P < 0.001). On the BEV trial, performance was significantly slower than after both other treatments (P < 0.0001). There were no speed-accuracy tradeoffs (P > 0.10). T2EX was longer after CAF consumption compared with both CHO and BEV trials (P < 0.05), and T2EX was longer after CHO than after BEV (P < 0,05). No differences were found in the ratings of perceived exertion, mean heart rate, and relative exercise intensity (% (V)over dotO(2max)x; P > 0.05). Conclusion: Caffeine in a performance bar call significantly improve endurance performance and complex cognitive ability during and after exercise. These effects may be salient for spoils performance in which concentration plays a major role.