Exercise training from late middle age until senescence does not attenuate the declines in skeletal muscle aerobic function

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Betik, Andrew C, Thomas, Melissa M, Wright, Kathryn J, Riel, Caitlin D and Hepple, Russell T (2009) Exercise training from late middle age until senescence does not attenuate the declines in skeletal muscle aerobic function. American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 297 (3). R744-R755. ISSN 03636119

Abstract

We previously showed that 7 wk of treadmill exercise training in late-middle-aged rats can reverse the modest reductions in skeletal muscle aerobic function and enzyme activity relative to values in young adult rats (Exp Physiol 93: 863–871, 2008). The purpose of the present study was to determine whether extending this training program into senescence would attenuate the accelerated decline in the muscle aerobic machinery normally seen at this advanced age. For this purpose, 29-mo-old Fisher 344 Brown-Norway rats underwent 5 or 7 mo of treadmill exercise training. Training resulted in greater exercise capacity during an incremental treadmill exercise test and reduced percent body fat in 34- and 36-mo-old rats and improved survival. Despite these benefits at the whole body level, in situ muscle aerobic capacity and muscle mass were not greater in the trained groups at 34 mo or 36 mo of age. Similarly, the trained groups did not have higher activities of citrate synthase (CS) or Complex IV in homogenates of either the plantaris (fast twitch) or the soleus (slow twitch) muscles at either age. Finally, protein expression of CS (a marker of mitochondrial content) and peroxisome proliferator-activated receptor-γ coactivator-1 (relating to the drive on mitochondrial biogenesis) were not higher in the trained groups. Therefore, although treadmill training from late middle age into senescence had significant benefits on running capacity, survival, and body fat, it did not prevent the declines in muscle mass, muscle aerobic capacity, or mitochondrial enzyme activities normally seen across this age, revealing a markedly diminished plasticity of the aerobic machinery in response to endurance exercise at advanced age. See also Corrigendum: Betik, Andrew C, Thomas, Meliisa M, Wright, Kathryn J, Riel, Caitlin D and Hepple, Russell T (2009) Corrigendum: Exercise training from late middle age until senescence does not attenuate the declines in skeletal muscle aerobic function. American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, 297 (5). R1622-R1623

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Item type Article
URI https://vuir.vu.edu.au/id/eprint/10719
DOI 10.1152/ajpregu.90959.2008
Official URL http://ajpregu.physiology.org/content/297/3/R744.f...
Subjects Historical > FOR Classification > 0606 Physiology
Historical > FOR Classification > 1106 Human Movement and Sports Science
Historical > Faculty/School/Research Centre/Department > Institute of Sport, Exercise and Active Living (ISEAL)
Keywords ResPubID26400, aging, oxygen uptake, sarcopenia, mitochondria, endurance training
Citations in Scopus 41 - View on Scopus
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