Studies have shown that exercise can help ward off heart disease and cancer and a new research shows that the reason why may be found within cells themselves.

German researchers report that endurance athletes had longer telomeres in their white blood cells than healthy, nonsmoking adults who did not exercise regularly.

Telomeres are DNA at the tips of chromosomes that protect the cell. They can be thought to be plastic tips attached to the ends of shoelaces which prevent the lace from fraying as per Emmanuel Skordalakes who is an assistant professor of gene expression and regulation at The Wistar Institute in Philadelphia.

Cells continue to divide over the life span and every time a cell divides the telomere is shortened. The cell stops dividing when the telomere gets too short.

When this begins to happen, people age and gradually losing muscle strength, skin elasticity, vision, hearing and mental abilities and so on, according to Skordalakes.

The researchers measured the length of white blood cell telomeres of endurance athletes and compared them to the telomeres of age-matched healthy nonsmokers who typically exercised lesser than an hour every week.

The participants included professional runners with an average age of 20 who ran more than 45 miles a week as part of the German National track and field team. Another group of athletes were middle-aged who had done endurance exercise since youth and ran an average of nearly 50 miles every week.