Effect Of Rehydration And Carbohydrate Ingestion On Physical, Skilled And Cognitive Performance During Basketball

Abstract

PURPOSE To investigate the effects of hydration and ingestion of a carbohydrateelectrolyte beverage on exercise performance during a simulated basketball “game”. METHODS A reproducible, high-intensity, “stop-and-go” exercise protocol (120 min including a 30-min warm-up and a 15-min half-time break) designed to closely mimic the physical demands of a competitive basketball game was utilized. Each “half” of the protocol included: 20 maximum vertical jumps, 20 maximum 15m sprints, 23 “defensive patterns” (70% VO2max), 56 3s “rests”, 15 25s “rests”, 15 “jogs” (2X20m @ 80% VO2max), and 5 “walks” (2X10m @ 40% VO2max). Twelve participants (6 men, 6 women) took part in 3 counterbalanced exercise sessions where a sports drink (6% carbohydrate-electrolyte, CHO), flavored placebo (PLA) or no fluid (CON) was provided. During CHO and PLA, participants ingested 20-ml fluid per kg body weight in portions of 2–5 ml/kg prior to and during exercise. Blood samples were taken and various performance measures were recorded prior to, during, and following exercise. RESULTS Blood glucose was higher in CHO compared to PLA & CON. Heart rate was greater in CON vs. CHO and PLA during the second “half” (172±2 bpm vs. 164±4 and 165±3 bpm, respectively). Participants lost more body water following CON compared to CHO and PLA as indicated by change in nude body weight following exercise (2.1±0.2 kg vs. 0.6±0.1 and 0.8±0.2 kg, respectively). Rating of perceived exertion (RPE) was lower in CHO (16.3±0.3) compared to CON (17.0±0.3) in the “4th quarter”. Time to perform a dribbling/lay-up task at the end of the “game” increased from CHO (167.9±2.6 s) to PLA (169.4±3.2 s) to CON (172.3±3.0, not significant; p=0.11). Blood lactate concentration, 15-m sprint time, vertical jump height, and body temperature were not different between trials. There was a trend for improvement in free throw accuracy and Stroop color-word score in CHO compared to PLA & CON (not significant) CONCLUSION Fluid and carbohydrate consumption reduced RPE, but had little effect on repetitive anaerobic performance during “basketball”. Further investigation is necessary to determine whether fluid and/or carbohydrate may affect skilled or cognitive tasks during basketball or other “stop-and-go” sports. Supported by the Gatorade Sports Science Institute.