Previous studies have shown how exercise helps stave off cancer and heart diseases, but now new research reveal the reason is to be found within the cells themselves.

According to the German researchers of the study, the white blood cells of endurance athletes have longer telomeres i. e. DNA at the tips of chromosomes which protect the cell, longer than that of healthy, non-smoking adults who also do not exercise on a regular basis.

Emmanuel Skordalakes, an Assistant Professor of Gene Expression and Regulation explains telomeres as much like the plastic tips on shoelace ends that prevent the lace from fraying.

Cells divide over our life span and every time a cell divides, it means the telomere is shortened and when it gets too short, the cell stops dividing. When cell division stops, it results in people aging, gradually losing their muscle strength, elasticity of their skin, vision, hearing and mental abilities, etc.

For the study, the length of white blood cell telomeres of endurance athletes was measured and compared to the control group comprising of age-matched healthy non-smokers who exercised less than one hour a week.

Unsurprisingly, the athletes had a slower resting heart rate, a sign of cardiovascular fitness, including lower blood pressure, lower body mass index and lower cholesterol than the control group.

Athletes were also found to have longer telomeres, including increased activity of telomerase, an enzyme that maintains the telomere, compared to those of a similar age, but who did not exercise.

‘This is direct evidence of an anti-aging effect of physical exercise,’ study author Dr. Ulrich Laufs said in a statement.

The study findings will be published in an upcoming print issue of Circulation.

Till only recently, it was thought the primary role of white blood cells was to fight off infections, but new research shows they do much more, including continuously looking out for abnormal cell growths like the ones that cause cancer, and getting rid of them.

This explains why cancer rates increase with age, as it could be due to the fact that the white blood cells also begin to age, becoming less efficient at handling abnormal growths. If, white blood cells can be kept young by exercising which prevents the telomere from shortening, it explains why exercise offers protection against developing cancer.

Likewise, in heart disease, aging white blood cells, together with high blood pressure and other factors, may allow quick accumulation of plaques. Exercising and keeping white blood cells young, we may continue to efficiently clear away plaques.

The question remains of how much exercise is necessary to keep telomeres from shortening. Since, we do not know, the best bet is to exercise regularly, as previous research shows even moderate activity is beneficial for the telomeres.