EFFECTS OF CARBOHYDRATE INGESTION ON PERFORMANCE DURING A COMPETITIVE ???STOP-AND-GO??? SPORT (BASKETBALL).

Abstract

PURPOSE: To investigate the effects of ingestion of a carbohydrate-electrolyte beverage on exercise performance during a simulated “stop-and-go” team sport (basketball). 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) was designed to closely mimic the physical and mental demands of a competitive basketball game. Each “half” of the protocol included: 15 maximum vertical jumps, 20 maximum 15m sprints, 30 “defensive patterns” (70% VO2max), 15 4s “rests”, 20 30s “rests”, 15 “jogs” (2X20m @ 80% VO2max), and 7 “walks” (2X10m @ 40% VO2max). Ten female college basketball players performed this protocol while ingesting a sports drink (6% carbohydrate-electrolyte, CHO) or placebo (CON) using a double-blind, counterbalanced design. Participants ingested 20 ml fluid per kg body weight in portions of 2–5 ml/kg prior to exercise and during scheduled “time-out” rest periods. Blood samples were obtained pre-ingestion and at 13, 38, 67 and 92 min of exercise. Various performance measures were recorded prior to, during, and following exercise. RESULTS: Blood glucose was higher in the CHO trial compared to CON (significant at 38 min). Blood lactate and RPE were not different between trials, but increased with exercise. Subjects lost body water following exercise as indicated by nude body weight, but no difference existed between conditions. No differences in maximum vertical jump, free throw completion or timed jump shot completion were noted over time or between trials. Fifteen-meter sprint times were faster in the last 10 min of the second half during CHO and “dribble-and-shoot” basketball performance scores were higher following exercise in CHO compared to CON. CONCLUSION: It appears carbohydrate-electrolyte ingestion increased performance in some, but not all, basketball specific skills. Improvements that were observed occurred during or following the final quarter of play. Supported by the Gatorade Sports Science Institute.