Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle

J Appl Physiol (1985). 1999 Aug;87(2):598-604. doi: 10.1152/jappl.1999.87.2.598.

Abstract

We examined the effect of glycogen-depleting exercise on subsequent muscle total creatine (TCr) accumulation and glycogen resynthesis during postexercise periods when the diet was supplemented with carbohydrate (CHO) or creatine (Cr) + CHO. Fourteen subjects performed one-legged cycling exercise to exhaustion. Muscle biopsies were taken from the exhausted (Ex) and nonexhausted (Nex) limbs after exercise and after 6 h and 5 days of recovery, during which CHO (CHO group, n = 7) or Cr + CHO (Cr+CHO group, n = 7) supplements were ingested. Muscle TCr concentration ([TCr]) was unchanged in both groups 6 h after supplementation commenced but had increased in the Ex (P < 0.001) and Nex limbs (P < 0.05) of the Cr+CHO group after 5 days. Greater TCr accumulation was achieved in the Ex limbs (P < 0.01) of this group. Glycogen was increased above nonexercised concentrations in the Ex limbs of both groups after 5 days, with the concentration being greater in the Cr+CHO group (P = 0.06). Thus a single bout of exercise enhanced muscle Cr accumulation, and this effect was restricted to the exercised muscle. However, exercise also diminished CHO-mediated insulin release, which may have attenuated insulin-mediated muscle Cr accumulation. Ingesting Cr with CHO also augmented glycogen supercompensation in the exercised muscle.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / analysis
  • Adult
  • Blood Glucose
  • Creatine / metabolism*
  • Diet
  • Dietary Supplements
  • Exercise / physiology*
  • Female
  • Glycogen / metabolism*
  • Humans
  • Insulin / blood
  • Male
  • Muscle, Skeletal / metabolism*
  • Phosphocreatine / analysis
  • Time Factors

Substances

  • Blood Glucose
  • Insulin
  • Phosphocreatine
  • Adenosine Triphosphate
  • Glycogen
  • Creatine