Effects of cycle strategy and fibre composition on muscle glycogen depletion pattern and subsequent running economy

Full text for this resource is not available from the Research Repository.

Suriano, Robert, Edge, Johann and Bishop, David (2010) Effects of cycle strategy and fibre composition on muscle glycogen depletion pattern and subsequent running economy. British Journal of Sports Medicine, 44 (6). pp. 443-448. ISSN 0306-3674 (print) 1473-0480 (online)


In this study, the effects of variable and constant-intensity cycling on muscle glycogen depletion patterns and subsequent running economy was examined. 60 minutes of cycling at a constant power (CON) or variable intensity (VAR) followed by a treadmill run to determine running economy was completed by nine male triathletes (Vo2max = 67.7 (4.9 ml) kg− min−1). During CON, there was greater glycogen depletion in the type I fibres compared with type II (0.08 (0.04) vs 0.02 (0.01) optical density (OD) units; p<0.05), while during VAR, there was greater glycogen depletion in the type II fibres compared with type I (0.06 (0.03) vs 0.03 (0.02) OD; p<0.05). The variation in muscle glycogen depletion patterns was not associated with the detriment in running economy, which was not significantly different between conditions (52.1 vs 52.8 ml kg−1 min−1). There was a strong correlation between total muscle glycogen depletion and the change in running Vo2 (r = 0.73, p<0.05) when the data from both trials were combined. There was also a negative correlation between type I fibre percentage and glycogen depletion within type II fibres during CON (r = −0.85, p<0.05). The results demonstrate that the decrease in running economy, subsequent to 60 minutes of cycling, is not affected by the cycling strategy employed. While different glycogen depletion patterns in the type I and II fibres were observed between conditions, total glycogen depletion may be more important to subsequent running economy. The percentage of type I fibres was associated with the glycogen depletion pattern during constant load, but not variable-intensity exercise.

Dimensions Badge

Altmetric Badge

Item type Article
URI https://vuir.vu.edu.au/id/eprint/7057
DOI https://doi.org/10.1136/bjsm.2007.046029
Official URL http://bjsm.bmj.com/content/44/6/443.abstract
Subjects Historical > Faculty/School/Research Centre/Department > Institute of Sport, Exercise and Active Living (ISEAL)
Current > FOR Classification > 1106 Human Movement and Sports Science
Historical > SEO Classification > 970111 Expanding Knowledge in the Medical and Health Sciences
Keywords ResPubID21161, efficiency, PAS stain, triathletes, variable intensity
Citations in Scopus 10 - View on Scopus
Download/View statistics View download statistics for this item

Search Google Scholar

Repository staff login