Creatine ingestion augments dietary carbohydrate mediated muscle glycogen supercompensation during the initial 24 h of recovery following prolonged exhaustive exercise in humans

Amino Acids. 2016 Aug;48(8):1831-42. doi: 10.1007/s00726-016-2252-x. Epub 2016 May 19.


Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here, we aimed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon. Fourteen healthy, male volunteers cycled to exhaustion at 70 % VO2peak. Muscle biopsies were obtained at rest immediately post-exercise and after 1, 3 and 6 days of recovery, during which Cr or placebo supplements (20 g day(-1)) were ingested along with a prescribed high CHO diet (37.5 kcal kg body mass(-1) day(-1), >80 % calories CHO). Oral-glucose tolerance tests (oral-GTT) were performed pre-exercise and after 1, 3 and 6 days of Cr and placebo supplementation. Exercise depleted muscle glycogen content to the same extent in both treatment groups. Creatine supplementation increased muscle total-Cr, free-Cr and phosphocreatine (PCr) content above placebo following 1, 3 and 6 days of supplementation (all P < 0.05). Creatine supplementation also increased muscle glycogen content noticeably above placebo after 1 day of supplementation (P < 0.05), which was sustained thereafter. This study confirmed dietary Cr augments post-exercise muscle glycogen super-compensation, and demonstrates this occurred during the initial 24 h of post-exercise recovery (when muscle total-Cr had increased by <10 %). This marked response ensued without apparent treatment differences in muscle insulin sensitivity (oral-GTT, muscle GLUT4 mRNA), osmotic stress (muscle c-fos and HSP72 mRNA) or muscle cell volume (muscle water content) responses, such that another mechanism must be causative.

Keywords: Glucose tolerance; Glycogen storage; Insulin sensitivity; Phosphocreatine.

Publication types

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

MeSH terms

  • Adult
  • Creatine / administration & dosage*
  • Dietary Carbohydrates / administration & dosage*
  • Gene Expression Regulation / drug effects
  • Glucose Tolerance Test
  • Glycogen / metabolism*
  • Humans
  • Male
  • Muscle Proteins / biosynthesis
  • Muscle, Skeletal / metabolism*
  • Physical Endurance / drug effects*
  • Physical Endurance / physiology


  • Dietary Carbohydrates
  • Muscle Proteins
  • Glycogen
  • Creatine