Rapid carbohydrate loading after a short bout of near maximal-intensity exercise

Med Sci Sports Exerc. 2002 Jun;34(6):980-6. doi: 10.1097/00005768-200206000-00012.


Purpose: One limitation shared by all published carbohydrate-loading regimens is that 2-6 d are required for the attainment of supranormal muscle glycogen levels. Because high rates of glycogen resynthesis are reported during recovery from exercise of near-maximal intensity and that these rates could in theory allow muscle to attain supranormal glycogen levels in less than 24 h, the purpose of this study was to examine whether a combination of a short bout of high-intensity exercise with 1 d of a high-carbohydrate intake offers the basis for an improved carbohydrate-loading regimen.

Methods: Seven endurance-trained athletes cycled for 150 s at 130% VO2peak followed by 30 s of all-out cycling. During the following 24 h, each subject was asked to ingest 12 g.kg-1 of lean body mass (the equivalent of 10.3 g.kg-1 body mass) of high-carbohydrate foods with a high glycemic index.

Results: Muscle glycogen increased from preloading levels (+/- SE) of 109.1 +/- 8.2 to 198.2 +/- 13.1 mmol.kg-1 wet weight within only 24 h, these levels being comparable to or higher than those reported by others over a 2- to 6-d regimen. Densitometric analysis of muscle sections stained with periodic acid-Schiff not only corroborated these findings but also indicated that after 24 h of high-carbohydrate intake, glycogen stores reached similar levels in Type I, IIa, and IIb muscle fibers.

Conclusion: This study shows that a combination of a short-term bout of high-intensity exercise followed by a high-carbohydrate intake enables athletes to attain supranormal muscle glycogen levels within only 24 h.

Publication types

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

MeSH terms

  • Adult
  • Dietary Carbohydrates / administration & dosage*
  • Exercise / physiology*
  • Glycogen / metabolism*
  • Humans
  • Male
  • Muscle Fibers, Skeletal / metabolism
  • Muscle, Skeletal / metabolism*
  • Periodic Acid-Schiff Reaction
  • Physical Endurance / physiology*
  • Time Factors


  • Dietary Carbohydrates
  • Glycogen