Does running make you old or keep you young?

I had a post up a couple of weeks ago pointing to a study that said that the muscles of endurance runners aged in proportion to the amount of running they did. The argument was around the length of telomeres in the muscle cells.

Telomeres are structures at the ends of human chromosomes that protect DNA from damage. To help you visualize them, they are often compared to the little plastic tips at the ends of shoelaces. As cells age and replicate, their telomeres shorten. When telomeres become critically short, cells stop functioning properly. So, the general idea is that telomeres may be a “biological clock” that reflects your physiological age/health more accurately than your chronological age. In other words, the longer the telomeres, the healthier the cells. (from here)

This post is just to note that - as ever - it is a complex business and not as straightforward as it might all seem.


There is another study which says that endurance training keeps cells "younger" with longer telomeres:

Leukocyte telomere length is preserved with aging in endurance exercise-trained adults and related to maximal aerobic capacity.

Our results indicate that Leukocyte Telomere length is preserved in healthy older adults who perform vigorous aerobic exercise and is positively related to maximal aerobic exercise capacity. This may represent a novel molecular mechanism underlying the "anti-aging" effects of maintaining high aerobic fitness.

Of course it is all complex. There is an interesting interview here which goes through the background to this. Telomere length, it says can be affected by:

• Genetics
• lack of sleep
• fish oil (there it is again)
• stress
• high blood sugar

So it might not have anything to do with the exercise.