MDA content increases in fast- and slow-twitch skeletal muscle with intensity of exercise in a rat

Previous work has shown that high-intensity (HI) exercise results in total body increased production of lipid peroxidation. These results suggest that exercise induces a higher level of oxidative stress in muscles leading to the production of various peroxides and aldehydes that are potentially toxic to cells. However, these past studies were carried out only with subjects that were exercised to exhaustion or at a very high intensity. In this paper, we report how a moderate-intensity (MI) exercise, which is more normally experienced, as well as a HI acute bout of exercise influenced oxidative stress-related reactions by measuring malonaldehyde (MDA) and lipid hydroperoxides (LH) in red vastus, white vastus, and soleus muscle. The muscles from untrained male Sprague-Dawley rats were removed immediately after either a HI 1-min run at 45 m/min (n = 8) or a 20-min MI run at 20 m/min (n = 8) and compared with a control group that did not run. MI exercise resulted in a 90% increase in MDA in white vastus and a ...