The influence of a 12% carbohydrate-electrolyte beverage on self-paced soccer-specific exercise performance. Issue 12 (December 2017)

• Record Type: Journal Article
• Authors: Harper, Liam D.; Stevenson, Emma J.; Rollo, Ian; Russell, Mark
• Is Part Of: Journal of science and medicine in sport. Volume 20:Issue 12(2017)
• Page Start: 1123
• Page End: 1129
• Publication Date: 2017-12
• Subjects: Football -- Skill -- Sucrose -- Maltodextrin -- Isomaltulose; Sports sciences -- Periodicals; Sports medicine -- Periodicals; Exercise -- Physiological aspects -- Periodicals; Sports -- physiology -- Periodicals; Sports Medicine -- Periodicals; Sportgeneeskunde; 617.102705
• DOI: 10.1016/j.jsams.2017.04.015
• Languages: English
• ISSNs: 1440-2440

Abstract

Abstract: Objectives: To assess the physiological and performance effects of a 12% carbohydrate-electrolyte beverage consumed at practically applicable time-points (i.e., before each half) throughout simulated soccer match-play. Design: Randomised, counterbalanced, crossover. Methods: Fed players (n = 15) performed 90-min of soccer-specific exercise (including self-paced exercise at the end of each half). Players consumed carbohydrate-electrolyte (CHO; 60 g × 500 ml −1, Na + 205 mg × 500 ml −1 ), placebo-electrolyte (PL) or water (Wat) beverages at the end of the warm-up (250 ml) and half-time (250 ml plus ad-libitum water). Blood was drawn before each half and every 15-min during exercise. Physical (15-m sprinting, countermovement jumps, self-paced distance, acceleration/deceleration count), technical (dribbling) and cognitive (memory, attention, decision-making) performance was assessed. Ratings of perceived exertion (RPE) and abdominal discomfort were measured. Results: Against Wat and PL, CHO increased (all p < 0.05) mean accelerations >1.5 m·s −2 during self-paced exercise (>+25%) and dribbling speed from 60-min onwards (>+3%). Mean sprinting speed improved (+2.7%) in CHO versus Wat. Blood glucose increased before and during each half in CHO versus PL and Wat (all p < 0.05). A 27% decline in glycaemia occurred at 60-min in CHO. RPE was comparable between trials. Cognition reduced post-exercise (p < 0.05); this decline was not attenuated by CHO. Abdominal discomfort increased during exercise but was similar between trials. Conclusions: Using more realistic fluid ingestion timings than have been examined previously, consuming a 12% carbohydrate-electrolyte beverage increased blood glucose, self-paced exercise performance, and improved dribbling speed in the final 30-min of exercise compared to water and placebo. Carbohydrates did not attenuate post-exercise reductions in cognition.