Take a good look at those runners in this months Boston Marathon- you may be seeing them around for a long time. New research suggests that phrase running for your life may apply literally when it comes to endu – rance athletes such as marathoners, whose exercise habits seem to have anti-aging effects deep down at the cellular level. Its among the most intriguing findings from a flurry of new studies showing how exercise contributes to healthy aging (see story below).Publishing their results in Circu – lation, Ulrich Laufs, MD, of Saarland University in Germany and colleagues compared signs of aging on the cellular level among active and sedentary subjects in two age groups. The younger group, in their 20s, consisted of professional track-and-field athletes-mostly on the national team, training about 45 miles a week-and sedentary individuals of the same age. The older group included middle-aged marathoners and triathletes-average age 51, with a typical training regimen of 50 miles a week-and their couch-potato peers.Even before sampling the participants white blood cells for testing, researchers could see a difference in the older marathoners. Christian Werner, MD, a co-author of the study, recalled in an interview, It was striking to see in our study that many of the middleaged athletes looked much younger than sedentary control subjects of the same age.
| How Much Exercise Do You Need? The 2008 Physical Activity Guidelines for Americans advise adults to do at least 150 minutes a week of moderate-intensity, or 75 minutes a week of vigorous-intensity aerobic activity, or an equivalent combination of moderate- and vigorous- intensity aerobic physical activity. Aerobic activity should be performed in episodes of at least 10 minutes, preferably spread throughout the week. Adults should also do muscle-strengthening activities that involve all major muscle groups performed on two or more days per week.On Patriots Day, April 19, the 114th Boston Marathon will involve up to 25,000 runners in the worlds oldest annual marathon. The 2010 race will mark John Hancock Financials 25th year as principal sponsor. Once again, too, the marathon field will include several hundred participants in the Tufts Presidents Marathon Chal lenge, which raises funds to support nutrition, medical and fitness programs. This years goal is $400,000. See www.tuftsmarathonchallenge.com |
Those apparent differences persisted right down to the cellular level, when scientists measured biological- as opposed to chronological- aging. They compared the lengths of telomeres, caps on the end of DNA strands that get snapped when cells divide and replicate. Shorter telomeres are a sign of biological aging; the discovery of telomeres function earned the 2009 Nobel Prize in medicine. (The omega-3s in fish oil may also protect telomeres in heart patients- see page 1.)The telomeres of both younger groups were about the same length. Researchers speculated that the study population may have been too small to detect subtle differences between the young athletes and sedentary controls.But the difference in the older athletes was striking. At the telomere level, the 50-ish marathoners were barely older than the 20-somethings, with telomeres only about 10% shorter. Overall, telomere loss in the middleaged runners was reduced by about 75%. The sedentary 50-year-olds, by contrast, had telomeres 40% shorter than the younger group.Dr. Werner cautioned, Notably, this calculation is limited by the cross-sectional design, the small sample size and the selection of rather extreme groups in the study, but it does prove the principle that long-term intense exercise goes along with a protection of telomeres. The extent of this effect may vary between individuals and depend on a number of other factors such as lifestyle.This is direct evidence of an antiaging effect of physical exercise, said Dr. Laufs. Our data improve the molecular understanding of the vasculoprotective effects of exercise, and underline the potency of physical training in reducing the impact of age-related disease.Anewly published study in Mecha – nisms of Ageing and Development adds support to the idea that a high level of aerobic fitness protects against the damage of advancing years. Scientists at the University of Colorado led by Thomas J. LaRocca tested four groups of younger (ages 18-32) and older (55-72) endurance-trained and sedentary adults, totaling 57 participants. To more objectively assess fitness, the researchers determined the subjects maximum aerobic capacity by measuring their oxygen consumption during maximal exercise and compared that to telomere length. They found that fitness in middle age and beyond was associated with longer telomeres-a reduction in the biological effects of aging.The findings may help explain why exercise seems to help keep you youthful. Our results indicate that telomere length is preserved in healthy older adults who perform vigorous aerobic exercise and is positively related to maximal aerobic exercise capacity, LaRocca and colleagues concluded. This may represent a novel molecular mechanism underlying the anti-aging effects of high aerobic fitness.But do you have to run marathons to turn back the clock? The answer isnt clear, said Dr. Werner: One can only speculate whether any form of exercise that is regularly performed over a long period of time would benefit telomeres. In any case, given the multiplicity of ways keeping active helps keep you young, becoming more physically active seems the surest way to outrun Father Time.TO LEARN MORE: Circulation, Dec. 15, 2009; abstract at circ.ahajournals.org/cgi/content/abstract/ 120/24/2438. Mechanisms of Ageing and Development, online ahead of print; abstract at dx.doi.org/10.1016/j.mad.2009.12.009.