Comparison of 2 Days of Moderate or High Carbohydrate Intake on Physical and Cognitive Performance in Female...

High carbohydrate (CHO) intakes are recommended in the 24-48 hr before soccer matches to increase glycogen stores and delay the development of match-related fatigue, but this concept is unexplored in female soccer players. This study compared the effects of 2 days of divergent CHO intake on physical and cognitive performance during a simulated soccer match protocol. Using a double-blind, placebo-controlled, crossover design, 15 female field-based intermittent team sport players consumed either a high CHO diet (6 g·kg body mass [BM]-1·day-1; HIGH) or an isocaloric moderate CHO diet (3 g·kg BM-1·day-1; MOD) for 2 days after completing a standardized (∼35 min) intermittent exercise protocol. For the main experimental trials, participants completed the Loughborough Intermittent Shuttle Test as 5 × 15-min blocks of intermittent running followed by a shuttle run time to exhaustion, with cognitive performance assessed before and after the test. There was no significant difference (6.9 [-71.1, 84.8] s) in time to exhaustion between conditions (HIGH, 295 ± 137 s; MOD, 288 ± 133 s; p = .852; g = 0.05). Sprint times were faster during HIGH compared with MOD at Block 3 (p = .021; g = 0.33), Block 4 (p = .035; g = 0.31), and Block 5 (p < .001; g = 0.34). Rating of perceived exertion was lower during HIGH compared with MOD after Block 1 (p < .001; g = 0.78) and Block 2 (p = .018; g = 0.49). Reaction time in the Task Switching test was improved from pre- to postexercise in HIGH (p = .017; g = 0.67) but not MOD (p = .913; g = 0.05). These results suggest that female soccer players may benefit from increasing daily CHO intake to at least 6 g/kg BM for the 2 days preceding competitive matches.