Effects of exercise mode on muscle glycogen restorage during repeated days of exercise

Pascoe, David D., Costill, David L., Robergs, Robert A., Davis, Jacqueline, Fink, William J., & Pearson, David R. (1990) Effects of exercise mode on muscle glycogen restorage during repeated days of exercise. Medicine and Science in Sports and Exercise, 22(5), pp. 593-598.

View at publisher

Abstract

The purpose of this study was to examine differences in muscle glycogen storage during three successive days of running or cycling. In a crossover design, seven male subjects performed two 3-d trials of either running (trial R) or cycling (trial C) for 60 min at 75% VO2max. Biopsy samples were obtained before and after each day’s exercise from the gastrocnemius (trial R) or vastus lateralis (trial C) muscle. Diets in the 2 d preceding and during each trial contained 5 g carbohydrate · kg−1·d−1 and 14,475 ± 402 kJ·d−1. Mean pre-exercise glycogen content (mmol-kg−1 wet wt.) was significantly reduced in both trials on day 3 (103.4 ± 6.0) when compared to day 1 and day 2 (119.9 ± 6.8 and 116.4 ± 5.7, respectively). Day 1 glycogen reduction was significantly greater in trial C (P < 0.03), and glycogen restorage was greater (P < 0.02) only in trial C between the 1st and 2nd d. On day 3, spectro-photometric analysis of PAS strains showed that pre-exercise glycogen content in either muscle group was significantly (P < 0.01) less in Type I as compared to Type II fibers. This difference in fiber glycogen storage did not appear to be attributable to muscle damage as negligible leukocyte infiltration and low blood CK levels were obtained. No difference between modes were observed for CK values throughout the trials. These data suggest that the depressed glycogen storage before the 3rd d of exercise was due to the moderate carbohydrate intake.

Impact and interest:

17 citations in Scopus
14 citations in Web of Science®
Search Google Scholar™

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 96960
Item Type: Journal Article
Refereed: Yes
Keywords: carbohydrate, adult; article; clinical trial; controlled study; cycling; diet; exercise; glycogen muscle level; human; human experiment; male; muscle biopsy; normal human; priority journal; running, Adult; Bicycling; Creatine Kinase; Dietary Carbohydrates; Exercise; Glycogen; Human; Lactates; Male; Muscles; Physical Endurance; Pilot Projects; Running; Support, Non-U.S. Gov't
ISSN: 1530-0315
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Schools > School of Exercise & Nutrition Sciences
Deposited On: 18 Jul 2016 23:55
Last Modified: 18 Jul 2016 23:55

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page