A study comparing muscle structure between active and inactive people found that older people who regularly do endurance exercise maintain similar muscle characteristics to younger counterparts.

Researchers learned that, when compared to inactive people, those who regularly do endurance exercise maintain muscle fiber size better. In older active people, the arrangement of muscle fiber nuclei, which act as the control centers for muscle tissue, was also more similar to that of younger people.

Endurance exercise refers to any aerobic exercise sustained over an extended period of time that improves the endurance of the cardiovascular or muscular system. Examples include cycling, running, and walking.

Researchers used 3D microscopy imaging to analyze the structure of muscles. Samples were taken from people who do and do not regularly do endurance exercise in both younger and older people for an analysis and comparison. For untrained individuals, the aging process affected muscle fiber size and myonuclei, which control muscle function. However, there was no correlation between aging and these aspects of the muscles for people who exercised.

These findings suggest that inactivity has a more pronounced effect on muscle fibers and myonuclei than simply getting older, the authors conclude. This means that if people stay active as they age, the size of their muscles are more likely to be maintained, and the distribution of myonuclei might not deteriorate as much as they would if they were inactive.

To read the study, published in Experimental Physiology, click here