Glycogen synthesis in skeletal muscle following resistive exercise

• Main Author: Pascoe, David D.
• Other Authors: Costill, David L.
• Format: Others
• Published: 2011
• Subjects: Glycogen > Synthesis.; Weight lifting > Physiological aspects.
• Online Access: http://cardinalscholar.bsu.edu/handle/handle/179434; http://liblink.bsu.edu/uhtbin/catkey/720309

The purpose of this investigation was to determine the influence of post exercise carbohydrate (CHO) intake on the rate of muscle glycogen restorage after high intensity weight resistance exercise in untrained subjects. In a cross over design, eight male subjects performed sets (mean= 8.8) of 6 single leg knee extensions at 70% of one repletion max until 50% of full knee extension was no longer possible. Total force application was equated between trials using a strain gauge interfaced to a computer. Post exercise supplementation was administered at 0 and 1 hrs consisting of either a 23% CHO solution (1.5g•kg-1•hr-1) or an equal volume of water (H20). Total force production, pre-exercise muscle glycogen content, and degree of depletion (-40.6 and -44.3 mmol•kg-1) were not significantly different between H2O and CHO trials, respectively. During the initial 2 hrs recovery, the CHO trial had a significantly greater rate of muscle glycogen resynthesis as compared to the H2O trial. In the final 4 hrs of recovery no difference in repletion rates were observed. The glycogen content (mmol•kg-1 w.w.) and rates of restorage (mmol•kg-1 w.w.) during the recovery period were (mean + SE):TrialPost2 Hr6 HrRate (0-2 hrs)H2O101.3+ 13.1105.1+ 13.1105.5+ 13.01.3+ 2.2CHO91.7+ 11.8117.6+ 16.5123.4+ 15.1 *12.9+ 4.0*significance between trials, p <0.01Only the CHO supplementation trial restored pre-exercise muscle glycogen content after 6 hrs. The spectrophotometric analysis of glycogen stained muscle sections (PAS) indicated no difference between trials in the pre and post glycogen content for Type I and II fibers. The change in absorbance, when these samples were combined demonstrate greater glycogenolysis in the Type II (0.284 + 0.58) as compared to Type I (0.014 ± 0.076). During the recovery period, the change in absorbance supports greater glycogenesis in the Type II ( 0.096 + 0.060) when compared to no observed change in absorbance in the Type I fibers.Supported by a grant from Ross Laboratories. === Human Performance Laboratory