title: Carbohydrate ingestion and pre-cooling improves exercise capacity following soccer-specific intermittent exercise performed in the heat.
abstract: Ingestion of carbohydrate and reducing core body temperature pre-exercise, either separately or combined, may have ergogenic effects during prolonged intermittent exercise in hot conditions. The aim of this investigation was to examine the effect of carbohydrate ingestion and pre-cooling on the physiological responses to soccer-specific intermittent exercise and the impact on subsequent high-intensity exercise performance in the heat. Twelve male soccer players performed a soccer-specific intermittent protocol for 90 min in the heat (30.5°C and 42.2% r.h.) on four occasions. On two occasions, the participants underwent a pre-cooling manoeuvre. During these sessions either a carbohydrate-electrolyte solution (CHOc) or a placebo was consumed at (PLAc). During the remaining sessions either the carbohydrate-electrolyte solution (CHO) or placebo (PLA) was consumed. At 15-min intervals throughout the protocol participants performed a mental concentration test. Following the soccer-specific protocol participants performed a self-chosen pace test and a test of high-intensity exercise capacity. The period of pre-cooling significantly reduced core temperature, muscle temperature and thermal sensation (P < 0.05). Self-chosen pace was greater with CHOc (12.5 ± 0.5 km h(-1)) compared with CHO (11.3 ± 0.4 km h(-1)), PLA (11.3 ± 0.4 km h(-1)) and PLAc (11.6 ± 0.5 km h(-1)) (P < 0.05). High-intensity exercise capacity was improved with CHOc and CHO when compared with PLA (CHOc; 79.8 ± 7 s, CHO; 72.1 ± 5 s, PLAc; 70.1 ± 8 s, PLA; 57.1 ± 5 s; P < 0.05). Mental concentration during the protocol was also enhanced during CHOc compared with PLA (P < 0.05). These results suggest pre-cooling in conjunction with the ingestion of carbohydrate during exercise enhances exercise capacity and helps maintain mental performance during intermittent exercise in hot conditions.
authors.affiliation: Faculty of Life Sciences, School of Human Sciences, London Metropolitan University, North Campus, 166-220 Holloway Road, London, UK. neil.clarke@londonmet.ac.uk
authors.forename: N D
authors.initials: ND
authors.lastname: Clarke
authors.forename: D P M
authors.initials: DP
authors.lastname: Maclaren
authors.forename: T
authors.initials: T
authors.lastname: Reilly
authors.forename: B
authors.initials: B
authors.lastname: Drust
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D003080:Cold Temperature; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000494:pharmacology; D004435:Eating / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D010507:Periodicity; D010919:Placebos; D012916:Soccer / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D010919:Placebos