Abstract
In a previous study (J. G. Swallow, T. Garland, Jr., P. A. Carter, W.-Z. Zhan, and G. C. Sieck, J. Appl. Physiol. 84: 69-76, 1998), we found that in house mice both genetic selection (10 generations of artificial selection for high voluntary activity on running wheels) and access to running wheels (7-8 weeks) elicited a modest increase in maximal oxygen consumption. Based on these results, we hypothesized that genetic selection would affect the changes in endurance and oxidative capacity of the medial gastrocnemius (MG) muscle induced by wheel access (training response). Wheel access increased the isotonic endurance of the MG in both genetically selected and random-bred (control) mice. However, this exercise-induced improvement in isotonic endurance of the MG was similar between genetically selected and control mice. Wheel access also increased the succinate dehydrogenase activity of MG muscle fibers in both selected and control lines. However, this exercise- induced increase in succinate dehydrogenase activity was comparable between genetically selected and control animals. Taken together, these results indicate that the modest increase in maximal oxygen consumption associated with genetic selection is not reflected by the training-induced changes in oxidative capacity and endurance of MG muscle fibers.
Original language | English (US) |
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Pages (from-to) | 2326-2333 |
Number of pages | 8 |
Journal | Journal of applied physiology |
Volume | 87 |
Issue number | 6 |
DOIs | |
State | Published - Dec 1999 |
Keywords
- Artificial selection
- Fatigability
- Isotonic endurance
- Oxidative capacity
- Wheel running
ASJC Scopus subject areas
- Physiology
- Physiology (medical)