Carbohydrate ingestion and pre-cooling improves exercise capacity following soccer-specific intermittent exercise performed in the heat

Eur J Appl Physiol. 2011 Jul;111(7):1447-55. doi: 10.1007/s00421-010-1771-5. Epub 2010 Dec 16.

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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Athletic Performance / physiology*
  • Cold Temperature*
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / pharmacology
  • Eating / physiology*
  • Exercise / physiology
  • Hot Temperature* / adverse effects
  • Humans
  • Male
  • Periodicity
  • Placebos
  • Soccer / physiology*
  • Time Factors
  • Young Adult

Substances

  • Dietary Carbohydrates
  • Placebos