Aerobic activities like jogging and
interval training can make our cells biologically younger; weight
training did not have the same effect.
Aerobic
activities like jogging and interval training can make our cells
biologically younger, according to a noteworthy new experiment. Weight
training may not have the same effect, the study found, raising
interesting questions about how various types of exercise affect us at a
microscopic level and whether the differences should perhaps influence
how we choose to move.
There is
mounting and rousing evidence that being physically active affects how
we age, with older people who exercise typically being healthier, more
fit, better muscled and less likely to develop a variety of diseases and
disabilities than their sedentary peers. But precisely how, at an
interior, molecular level, exercise might be keeping us youthful has not
been altogether clear. Past studies have shown that exercise alters the
workings of many genes, as well as the immune system, muscle-repair
mechanisms and many other systems within the body.
Some
researchers have speculated that the most pervasive anti-aging effects
of exercise may occur at the tips of our chromosomes, which are capped
with tiny bits of matter known as telomeres. Telomeres seem to protect
our DNA from damage during cell division but, unfortunately, shorten and
fray as a cell ages. At some point, they no longer safeguard our DNA,
and the cell becomes frail and inactive or dies.
Many scientists believe that telomere length is a useful measure of a cell’s functional age.
But
researchers also have found that telomeres are mutable. They can be
lengthened or shortened by lifestyle, including exercise. A 2009 study,
for instance, found that middle-aged competitive runners tended to have
much longer telomeres than inactive people of the same age. Their
telomeres were, in fact, almost as lengthy of those of healthy, young
people. But that study was associational; it showed only that older
people who ran also were people with extended telomeres, not that the
exercise necessarily caused that desirable condition.
So for the new study, which was published in November in the European Heart Journal,
many of the same scientists involved in the 2009 study decided to
directly test whether exercise would change telomeres. They also hoped
to learn whether the type and intensity of the exercise mattered.
The
researchers began by recruiting 124 middle-aged men and women who were
healthy but did not exercise. They determined everyone’s aerobic fitness
and drew blood to measure telomere length in their white blood cells
(which usually are used in studies of telomeres, because they are so
readily accessible). They also checked blood markers of the amount and
activity of each person’s telomerase, an enzyme that is known to
influence telomere length.
Then some of the volunteers randomly were assigned to continue with their normal lives as a control or to start exercising.
Others
started a supervised program of brisk walking or jogging for 45 minutes
three times a week, or a thrice-weekly, high-intensity interval program
consisting of four minutes of strenuous exercise followed by four
minutes of rest, with the sequence repeated four times.
The final group took up weight training, completing a circuit of resistance exercises three times a week.
Source: https://www.nytimes.com/2018/12/12/well/move/is-aerobic-exercise-the-key-to-successful-aging.html
