Telomeres are specialized structures of nucleoprotein that protect chromosome ends from persistent DNA damage. Each time a cell divides, it copies its DNA, packed into chromosomes and as a result, they get shortened. The researchers have found that each bout of moderate exercise provides fresh protection to the telomeres, helping the DNA, and in turn the cells to remain younger. The protection is constantly renewed upon exercise. And regular exercise, therefore, provides protection constantly to DNA from damage. Just moderate intensity physical activity helps do so.
A group of 2,401 white twins was studied by Tim D. Spector, a professor of genetic epidemiology at King's College London and collections, and was published in the Archives of Internal Medicine. It was found that people, who did a moderate amount of exercise about 100 minutes a week, had telomeres that on average looked like those of someone about five or six years younger than those who did the least about 16 minutes a week. Those who did the most doing about three hours a week of moderate to vivid activity had telomeres that appeared to be about nine years younger than those who did the least. As the amount of exercise increased, their length increased.
The researchers conclude that a sedentary lifestyle has an adverse effect on telomere length and may accelerate the aging process.
How does exercise affect telomeres? –
The compounds called nuclear respiratory factor 1 (NRF1) and peroxisome proliferator-activated receptor co co-activator 1α are responsible for telomere length. They regulate cellular growth and control the shortening of telomeres. It has been found that exercise boosts levels of both these factors, which protect them from being snipped away.
Simultaneously, exercise also helps reduce oxidative stress. Another significant finding is that physical exercise leads to activation of an important enzyme telomerase, which stabilizes the telomeres, reducing their erosion.
Endurance exercise training –
Long term aerobic training and higher aerobic exercise capacity (VO2 max) are associated with positive effects on aging. The researchers suggest that higher VO2 max is positively associated with telomere length. They also found that long-term endurance exercise training may provide a protective effect on muscle telomere length in both younger and older people. However, the favorable effect on their length is independent of known heart health benefits of regular aerobic exercise.
Strength training –
It has been found that strength training is also beneficial for maintenance of their length within normal rages. The researchers found that long-term strength training is not associated with an abnormal shortening of skeletal muscle telomere length. The minimum telomere length in PL (power lifters) remains within normal physiological ranges. The nub of the matter is that weight training leads to less shortening of them and is anti-aging.
It has been validated by many studies that regular aerobic exercise has a positive effect on telomere length, thus slowing down cellular senescence. Ubiquitously accepted standard of 30 minutes of an aerobic exercise most days of the week is enough to slow down cellular senescence. If more, it is still better. If combined with strengthening exercises, all the better.
There are certain questions about favorable effects of exercise on telomere length that need to be found, which include – is there a minimum amount of exercise that confers ideal telomere length maintenance ?; is there a threshold at which point exercise does not benefit telomere length maintenance ?; is the benefit exercise has to telomeres intensity-dependent?
It may take some time before satisfying answers to these questions are found, till then one should keep on doing exercise as per recommendations of WHO (World Health Organization).
Arch Intern Med. 2008; 168 (2): 154-158.
Med Sci Sports Exerc. 2008 Jan; 40 (1): 82-7.