Effects of Short-Term Aerobic Exercise on Single Muscle Fibers of Older Women
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Authors
Jones, Stephanie
Issue Date
2009
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Sarcopenia, or loss of muscle mass with aging, affects about 45% of
elderly humans (age 60 and older) in the United States. Previous studies
showed that strength training and long-term aerobic programs help combat
muscle loss, indicating that the best way to prevent or treat sarcopenia is with
exercise. The purpose of this study was to characterize the influence of a shortterm
(12 week) aerobic exercise training program on cellular composition and
size of muscle fibers in older women (60-80 yrs). We biopsied the vastus
lateralis muscle of nine older women before and after 12 weeks of aerobic
training. We the~ determined the change in composition of five myosin heavy
chain (MHC) isoforms using SDS-PAGE and the change in diameter of MHC I
and MHC lIa fibers using computer imaging. MHC I fibers increased by 180/0,
whereas MHC lIa fibers decreased by 17% from pre- to post-aerobic training.
Diameters of MHC I and MHC lIa fibers did not change. Therefore, we showed
that short-term aerobic exercise can change muscle fiber composition but not
fiber size. We also confirmed that muscle fiber changes can be induced in older
women and that starting and maintaining an aerobic training program is useful for
both the prevention and treatment of sarcopenia.
Description
vi, 27 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.