Effect of the classic 1-week glycogen-loading regimen on fat-loading in rats and humans

J Nutr Sci Vitaminol (Tokyo). 2010;56(5):299-304. doi: 10.3177/jnsv.56.299.

Abstract

The purpose of this study was to elucidate the fat-loading effect of the classic 1-wk glycogen-loading regimen histologically in rats and physiologically in humans. In the rat and human studies, an exhaustive swimming exercise and cycle ergometer exercise were loaded on day 1 of a 6-d feeding period, respectively. Thereafter, both the rats and humans were divided into a glycogen-loading regimen consisting of a 3-d high-fat diet and a 3-d high-carbohydrate diet or a 6-d high-carbohydrate diet. After the feeding period in the human study, the human subjects performed a test exercise on day 7 using a cycle ergometer. In the rat study, the intramuscular triglyceride (IMTG) content was 69% greater (p<0.05) after the glycogen-loading regimen than after the high-carbohydrate diet feeding on day 7. In the human study, the respiratory exchange ratios (RER) after the glycogen-loading regimen were 4.9-6% lower than those after the high-carbohydrate diet during the test exercise on day 7 (p<0.05). Our findings suggest that the classical 1-wk glycogen-loading regimen maintained the storage and enhanced the utilization of energy sources during exercise in the skeletal muscle, and that it provides a fat-loading effect, in addition to the glycogen-loading effect, to the skeletal muscle.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Blood Glucose / analysis
  • Cross-Over Studies
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / metabolism
  • Dietary Fats / administration & dosage*
  • Dietary Fats / metabolism
  • Energy Metabolism
  • Exercise Test
  • Glycogen / metabolism*
  • Humans
  • Male
  • Muscle, Skeletal / metabolism*
  • Oxygen Consumption
  • Rats
  • Rats, Wistar
  • Triglycerides / metabolism
  • Young Adult

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fats
  • Triglycerides
  • Glycogen