The ingestion of combined carbohydrates does not alter metabolic responses or performance capacity during soccer-specific exercise in the heat compared to ingestion of a single carbohydrate

J Sports Sci. 2012;30(7):699-708. doi: 10.1080/02640414.2012.665941. Epub 2012 Mar 6.

Abstract

This study was designed to investigate the effect of ingesting a glucose plus fructose solution on the metabolic responses to soccer-specific exercise in the heat and the impact on subsequent exercise capacity. Eleven male soccer players performed a 90 min soccer-specific protocol on three occasions. Either 3 ml · kg(-1) body mass of a solution containing glucose (1 g · min(-1) glucose) (GLU), or glucose (0.66 g · min(-1)) plus fructose (0.33 g · min(-1)) (MIX) or placebo (PLA) was consumed every 15 minutes. Respiratory measures were undertaken at 15-min intervals, blood samples were drawn at rest, half-time and on completion of the protocol, and muscle glycogen concentration was assessed pre- and post-exercise. Following the soccer-specific protocol the Cunningham and Faulkner test was performed. No significant differences in post-exercise muscle glycogen concentration (PLA, 62.99 ± 8.39 mmol · kg wet weight(-1); GLU 68.62 ± 2.70; mmol · kg wet weight(-1) and MIX 76.63 ± 6.92 mmol · kg wet weight(-1)) or exercise capacity (PLA, 73.62 ± 8.61 s; GLU, 77.11 ± 7.17 s; MIX, 83.04 ± 9.65 s) were observed between treatments (P > 0.05). However, total carbohydrate oxidation was significantly increased during MIX compared with PLA (P < 0.05). These results suggest that when ingested in moderate amounts, the type of carbohydrate does not influence metabolism during soccer-specific intermittent exercise or affect performance capacity after exercise in the heat.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Athletic Performance / physiology*
  • Carbohydrate Metabolism / drug effects*
  • Diet / methods*
  • Dietary Sucrose / pharmacology
  • Drug Combinations
  • Exercise / physiology*
  • Fructose / pharmacology
  • Glucose / pharmacology
  • Glycogen / metabolism
  • Hot Temperature*
  • Humans
  • Male
  • Monosaccharides / pharmacology*
  • Muscle, Skeletal / physiology
  • Oxidation-Reduction
  • Physical Fitness
  • Soccer / physiology*

Substances

  • Dietary Sucrose
  • Drug Combinations
  • Monosaccharides
  • Fructose
  • Glycogen
  • Glucose