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

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

Author information

1
School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK.
2
Human Metabolic Physiology and Nutrition, QinetiQ Centre for Human Sciences, Farnborough, UK.
3
School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK. paul.greenhaff@nottingham.ac.uk.
4
School of Life Sciences, The Medical School, Nottingham, NG7 2UH, UK. paul.greenhaff@nottingham.ac.uk.

Abstract

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

PMID:
27193231
PMCID:
PMC4974290
DOI:
10.1007/s00726-016-2252-x
[Indexed for MEDLINE]
Free PMC Article

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