How Exercising Keeps Your Cells Young
Introduction (Via NYT)
Recently, scientists in Germany gathered several groups of men and women to look at their cells’ life spans. Some of them were young and sedentary, others middle-aged and sedentary. Two other groups were, to put it mildly, active. The first of these consisted of professional runners in their 20s, most of them on the national track-and-field team, training about 45 miles per week. The last were serious, middle-aged longtime runners, with an average age of 51 and a typical training regimen of 50 miles per week, putting those young 45-mile-per-week sluggards to shame.
Even more striking was what was going on beneath those deceptively youthful surfaces. When the scientists examined white blood cells from each of their subjects, they found that the cells in both the active and slothful young adults had similar-size telomeres. Telomeres are tiny caps on the end of DNA strands — the discovery of their function won several scientists the 2009 Nobel Prize in medicine. When cells divide and replicate these long strands of DNA, the telomere cap is snipped, a process that is believed to protect the rest of the DNA but leaves an increasingly abbreviated telomere. Eventually, if a cell’s telomeres become too short, the cell ‘‘either dies or enters a kind of suspended state,’’ says Stephen Roth, an associate professor of kinesiology at the University of Maryland who is studying exercise and telomeres. Most researchers now accept telomere length as a reliable marker of cell age. In general, the shorter the telomere, the functionally older and more tired the cell.