A telomere is a short stretch of repetitive DNA at the end of the DNA strands that make up the chromosomes. Three scientists – Elizabeth Blackburn, Carol Greider and Jack Szostak – won the 2009 Nobel Prize in Physiology or Medicine for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.
Your logical question about now is, “So what?” I’m glad you asked. I’ll try not to get too technical in answering. The telomeres at the end of DNA strands shorten each time a cell divides. Eventually there’s no telomere left, so the cell either dies or enters into senescence – that’s aging. The longer the telomere, the longer its life; the more long telomeres we have, the better off we are and the longer we’re likely to live.
Remember the phrase, “Youth is wasted on the young?” It fits here. Both active and inactive young people were compared by some German scientists; one of them was Dr. Christian Werner, an internal-medicine resident at Saarland University. He concluded that young adults in their twenties have telomeres of about the same length, whether they do lots of exercise or very little.
You ask, “But I’m not young anymore; what happens as I age?” Good question. They found that middle-aged, relatively inactive adults had telomeres forty percent shorter than those of the young subjects.
Now to the big one: They found that middle-aged adults who were very active physically – longtime runners – had telomeres only ten percent shorter than the young adults. So telomere loss was reduced by seventy-five percent in the older athletes. As Dr. Werner said, “Exercise, at the molecular level, has an anti-aging effect.”
Thomas LaRocca, while a Ph.D candidate at the University of Colorado, tested people fifty-five to seventy-two years old for their VO2max – their maximum aerobic capacity – and the length of their cells’ telomeres. The higher the VO2max, the longer the telomeres. Did I mention that your VO2max is a strong indicator of your fitness? So those who exercise have both higher VO2max and longer telomeres.
How much exercise is enough to provide significant benefit? That’s uncertain, but scientists do know that long-term endurance training is associated with a slower rate of telomere erosion compared with those who do not exercise. As Dr. Werner said, “Any form of intense exercise that is regularly performed over a long period of time will improve telomere biology.”