Almost any amount and type of physical activity may slow aging deep within our cells, a new study finds. And middle age may be a critical time to get the process rolling, at least by one common measure of cell aging.
Dating a cell's age is tricky, because its biological and chronological ages rarely match. A cell could be relatively young in terms of how long it has existed but function slowly or erratically, as if elderly.
Today, many scientists have begun determining a cell's biological age — meaning how well it functions and not how old it literally is — by measuring the length of its telomeres.
For those of us who don't know every portion of our cells' interiors, telomeres are tiny caps found on the end of DNA strands, like plastic aglets on shoelaces. They are believed to protect the DNA from damage during cell division and replication.
As a cell ages, its telomeres naturally shorten and fray. But the process can be accelerated by obesity, smoking, insomnia, diabetes and other aspects of health and lifestyle.
In those cases, the affected cells age prematurely.
However, recent science suggests that exercise may slow the fraying of telomeres. Past studies have found, for instance, that master athletes typically have longer telomeres than sedentary people of the same age, as do older women who frequently walk or engage in other fairly moderate exercise.