Our DNA is located in 23 pairs of chromosomes. These chromosomes have genes located at specific locations that contain the recipes for everything made by our bodies. The ends of the chromosomes have telomeres, which are repeating sequences of specific base pairs (the alphabet of our DNA) that don’t code for anything and act like a protective mechanism. They prevent the chromosomes from sticking to each other and keep the ends from fraying. However, as we age, or more specifically, as a DNA strand is copied, the telomeres get shorter. This is thought to be a significant factor in aging, disease, and cancer. Therefore, there is significant interest in ways that we might be able to keep longer telomeres.
A group of researchers (Colon, Hodgson, Donlon, & Murphy, 2019) compared the telomere length of small numbers of competitive triathletes versus recreationally active men. They found that the triathletes had longer telomeres compared to the recreational athletes. So then the question arises, what makes them different?
Colon et al didn’t find conclusive evidence but they did find correlations. Correlations are relationships that are not necessarily causal but are connected in some form. For example, sales rates of warm drinks and mitts probably seem connected because they both increase at similar times of the year but that doesn’t mean that one is causing the other. Colon et al found that the competitive athletes had longer telomeres and this seemed to be associated with maximal oxygen uptake (VO2 max, or the maximum rate that the body can use oxygen), lactate threshold (the point when the body can no longer clear lactate faster than it is being created), and running economy (how much energy it takes to run at a particular level).
Colon et al indicate that the triathletes in their study would be sub elite based on their fitness numbers. This is important because other studies have found that intense endurance activity is associated with cell damage. Therefore, there may be a best level or intensity of exercise for cell and DNA health.
What I find fascinating is how much we still don’t know, but also, what will we do with information as we find it? I can’t see elite athletes deciding to train less if we discover it’s harmful and we’ve known for a long time that exercise is healthy but that doesn’t seem to affect the decisions of many. Will the idea that exercise contributes to anti-aging change any of that?