Newswise, December 29, 2015--Elite runners do not experience
the muscle weakening associated with aging as non-athletes do. A new study
published in American Journal of Physiology—Cell Physiology examines
if their superb fitness is because their muscles have not aged.
Movement and strength come from the muscle fibers that make up
a muscle group contracting and generating tension. Muscle weakening happens
when the fibers contract slower and with less force.
A team of Canadian
researchers hypothesized that the constant physical training of older elite
runners preserved their muscle fibers such that the fibers behaved like those
of young adults.
Muscle fiber samples were taken from the quadriceps of older
elite runners and non-athlete adults in the same age range.
“One of the most
unique and novel aspects of this study are the exceptional participants,” says
lead author Geoff Power of University of Guelph in Canada.
“These are
individuals in their 80s and 90s who actively compete in the world
masters
track and field championships. In the study, we had seven world champions, and
everyone placed in the top four of their respective events.”
The fibers’ contraction speed and force were compared to
fibers from 23-year-old non-athlete adults.
Muscle fibers from older
non-athletes contracted considerably slower and weaker than fibers from young
non-athletes. To the researchers’ surprise, the muscle fibers of masters
athletes contracted at a speed and force similar to those of older non-athlete
adults, not the young adults.
Success in high-performance sports in old age
does not appear to be due to maintained contraction capability of the fibers,
Power says.
This study suggests that aging is associated with decreased
muscle quality regardless of physical activity status, according to Power.
However, other studies have shown that muscle fibers can be arranged in a
variety of ways to optimize strength, speed and power of the whole muscle,
Power says, so there are many structural ways to compensate for the reduced
performance at the fiber level to maintain performance at the whole muscle
level.
Researchers from McGill University, University of Calgary and
University of Quebec at Montreal were also involved in the study. The article
“Reduction in single muscle fiber rate of force development with aging is not
attenuated in world class older masters athletes” is published ahead-of-print in American Journal of
Physiology—Cell Physiology.
About the American Physiological Society
Physiology is the study of how molecules, cells, tissues and organs function in health and disease. Established in 1887, the American Physiological Society (APS) was the first U.S. society in the biomedical sciences field. The Society represents more than 10,000 members and publishes 15 peer-reviewed journals with a worldwide readership.
Physiology is the study of how molecules, cells, tissues and organs function in health and disease. Established in 1887, the American Physiological Society (APS) was the first U.S. society in the biomedical sciences field. The Society represents more than 10,000 members and publishes 15 peer-reviewed journals with a worldwide readership.
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