A recent study, as reported in the New York Times, has revealed that exercise not only made middle-aged people appear younger, but the youthful effect went below the surface and actually benefited their cells at the DNA level. The way that scientists were able to determine this was by exploiting a Nobel Prize winning technology that measures parts of the DNA known as telomeres.

Telomeres are repetitive sequences of DNA located at the ends of our chromosomes that protect them from deterioration. When our cells divide, the replication process cannot duplicate the entire length of the chromosome, so some of it is lost. In a way, telomeres are “disposable” pieces of DNA that can be clipped without harming the DNA of the chromosome, where the important genetic information resides.

Consequently, with replication, the telomeres become shorter and shorter, until they reach a critical length whereby cell division stops, essentially ending the life cycle of the cell. Because of this, it is generally accepted that because the length of the telomere indicates the number of times a cell has divided, it is, by extension, a reliable gauge of the cell’s age.

By exploiting this fact, researchers wanted to determine if an active lifestyle would effect the age of their cells. What they found was an age-related effect in relation to the amount of exercise in a person’s life. In other words, young people showed little, if any, difference in their telomeres regardless of whether they were extremely active or sedentary throughout their day. This may be due to the fact that they have not lived long enough to experience significant clipping of their telomeres.

However, in middle-aged subjects, the difference was significant. In fact, when people with an average age of 51 years were compared to young people in their 20s, researchers discovered that sedentary individuals had lost as much as 40% of their telomeres as a result of aging.

On the other hand, older people who were active had what was referred to as “youthful telomeres” which had lost only 10% of the DNA sequences when compared to young people who were comparatively active. On the whole, vigorous exercise resulted in 75% reduction in telomere loss in older people, thus suggesting the exercise has an anti-aging effect at the cellular level.

While the findings, published in the journal Circulation, are exciting, there are many unanswered questions that open the doors for future inquiry. For example, the subjects in the study engaged in fairly rigorous exercise, running for as much as 45-50 miles each week. This raises the question of whether this level of exertion is required to obtain the benefits for our cells.

Whatever be the case, the study lends further support to the benefits of exercise, something we are all familiar with, especially in light of the current obesity epidemic. Exercise is a means to become healthy by increasing your metabolism, which not only burn more calories (thus reducing fat), but also strengthens your immune system and helps regulate the breakdown of sugar in your blood.

Exercise strengthens your muscles, bones, heart and lungs, and makes you sweat, which clears the body of waste products and toxins. Being physically active also helps to reduce or avoid such problems as sleep apnea, hypertension, and even depression.

Needless to say, we all benefit from getting enough exercise. However, it is important to know your abilities and limitations, so before embarking on any exercise regimen, speak with your physician or an experienced trainer. For more information, check out the Physical Activity Guidelines brought to you by the U.S. Department of Health and Human Services.