Great News About Exercise

CNN reports in Strength training may reverse muscle aging by Reuters some good news for older folks and something kids of all ages should be imprinted with in terms of physical education habits.

Strength training may not only make older adults' muscles stronger, but younger as well, a small study suggests.

It's well known that resistance exercises improve muscle strength and function in young and old alike, but the new research suggests that strength training also affects older muscles on the level of gene expression -- essentially turning back the clock on muscle aging.

The study, published in the online journal PLoS One, looked at whether strength training affects the "gene expression profile" in older adults' muscle. Genes hold the instructions from which the body manufactures proteins; gene expression refers to the processes that translate these instructions into proteins.

Analyzing small samples of muscle tissue from a group of healthy young and older adults, researchers found that older and younger muscle tissues differed significantly in their gene expression profiles. The difference indicated that older muscle tissue had impaired functioning in mitochondria -- structures within cells that act as the cell's "powerhouse."

That impairment was reversible, however. After 14 of the older adults underwent 6 months of strength training, the gene expression profile in their muscles showed a more youthful appearance.

"In a very real sense, the muscle was younger," said lead study author Dr. Simon Melov of the Buck Institute for Age Research in Novato, California.

Experts have long known that exercise is good for younger and older adults alike, Melov told Reuters, but the new findings suggest that it can "actually rejuvenate muscle" in older individuals.