Whenever I’m able to drag myself out for an early-morning walk along the seafront or jog in the park, I’m always amazed by the handful of elderly individuals I see running comfortably. Incredibly, many of them appear to be fitter than the younger individuals out on their morning jog!

But how do these athletes maintain their fitness levels even into their old age? We may be tempted to attribute a decline in physical function with age solely to the ageing process. But how accurate is this? Are these older joggers simply superhuman and gifted, or is there more to the story of ageing and fitness?

What happens as we age?

We know that as we age, we generally become less active (Caspersen et al., 2000). So the question that then arises is: do we lose physical function as we age, causing us to move less and sit more, or do we move less and sit more, causing us to lose physical function?

The reality is that it’s likely a combination of both. Age does result in a decline in physical function, however, inactivity exacerbates this loss of function, causing us to decline, and effectively age more rapidly.

Biological age vs chronological age

It may surprise you to learn that ageing is not just about how many birthdays you’ve had, but also about your physical ability. This is what we refer to as chronological age vs biological age. While some people may be considered older, they can have a younger biological age, meaning they are fitter and have the physiology of a younger individual.

In fact, many athletes who maintain their fitness after retiring, keep up some level of training and are able to keep their biological age down. Those who continue to compete among other older athletes are known as Masters athletes, and these are often the people who provide us with inspirational and newsworthy stories. They are a living example of how maintaining activity can decelerate biological ageing.

What is a Masters athlete?

Masters athletes are individuals anywhere above the age of 35 who continue to compete in athletic events into their older age. They generally compete against individuals in their 5-year age group, and can even set records within their respective categories.

While you may think that 35 is young to be referred to as ‘older’, you may appreciate that it’s impressive for people aged 45-49 or 60-64 to still be competing in athletic events. Even more impressive is that some Masters athletes are over the age of 80, and there’s even a 100+ age group!

As I alluded to above, the impressive thing about Masters athletes is that they can have the anatomy and physiology of a much younger athlete. In fact, one impressive image taken from Wroblewski et al. (2011; Figure 1 in their paper) depicts MRI images of the legs of a 40-year-old triathlete, a 70-year-old triathlete and a 74-year-old sedentary man.

Astonishingly, the anatomy of the 70-year-old triathlete was not much different from that of the 40-year-old triathlete, with low body fat around the thighs and healthy-looking quadriceps muscles. However, the 74-year-old male had smaller quadriceps muscles which were infiltrated by fatty tissue, as well as a thicker subcutaneous level of fat around the thighs. This just goes to show what a great impact exercise and fitness can have on the body’s structure and function.

Is this preservation of fitness only observable on the macroscopic level?

This preservation of fitness actually extends beyond that which can be seen with the naked eye. When it comes to physiology, there are several cellular markers of ageing which can give us an indication of the younger biological age of an elderly individual, who maintains their exercise and fitness levels.

One such cellular marker is telomere length. It’s unlikely that you would have heard about telomeres before, unless you studied the physiology of ageing, so I’ll briefly touch on what they are.

Telomeres are pieces of DNA at the end of chromosomes which protect the chromosome from damage. Every time a cell divides, its telomeres shorten, and telomere length can therefore be used as an indicator of biological age. This is because as we get older, our cells would have divided more times, and our telomeres would most likely be shorter.

However, it appears that physical activity can help maintain longer telomeres (Cherkas et al., 2008; Werner et al., 2009). It can increase the activity of an enzyme called telomerase (Werner et al., 2009), which elongates the telomeres, stabilising telomere length and, in effect, appearing to reverse the ageing process!

It is worth pointing out that not all studies investigating telomeres have found that physical activity can lengthen them (Chilton et al., 2017), and we should therefore accept these findings with caution.

Other cellular and molecular markers of ageing that have been investigated with respect to physical activity include DNA methylation along with other epigenetic factors (Horvath, 2013; Horvath & Raj, 2018) and mitochondrial function (Lanza & Nair, 2008). It appears that both are improved with physical activity, but I won’t go into them here. Please feel free to refer to the papers reference above if you’d like to read more.

Conclusion

The good news is you don’t need to be a Masters athlete to enjoy the anti-ageing benefits of physical activity. Doing any amount of exercise is better than doing none at all and Cherkas et al.’s (2008) paper supports this, with average telomere length increasing gradually, the more weekly physical activity one engages in.

So if you’re not sure where to start, begin with one weekly session of light activity and try to keep it up over several weeks. Maybe try going out for a walk in the morning to enjoy the sunrise, or, as it begins to get warmer, consider going for a swim! Remember, you can begin exercising at any age, and your body will thank you for it!

References

Caspersen, C. J., Pereira, M. A., & Curran, K. M. (2000). Changes in physical activity patterns in the United States, by sex and cross-sectional age. Medicine & Science in Sports & Exercise, 32(9), 1601–1609. https://doi.org/10.1097/00005768-200009000-00013

Cherkas, L. F., Hunkin, J. L., Kato, B. S., Richards, J. B., Gardner, J. P., Surdulescu, G. L., Kimura, M., Lu, X., Spector, T. D., & Aviv, A. (2008). The association between physical activity in leisure time and leukocyte telomere length. Archives of Internal Medicine, 168(2), 154–158. https://doi.org/10.1001/archinternmed.2007.39

Chilton, W., O’Brien, B., & Charchar, F. (2017). Telomeres, Aging and Exercise: Guilty by Association? International Journal of Molecular Sciences, 18(12), 2573. https://doi.org/10.3390/ijms18122573

Horvath, S. (2013). DNA methylation age of human tissues and cell types. Genome Biology, 14(10), R115. https://doi.org/10.1186/gb-2013-14-10-r115

Horvath, S., & Raj, K. (2018). DNA methylation-based biomarkers and the epigenetic clock theory of ageing. Nature Reviews Genetics, 19(6), 371–384. https://doi.org/10.1038/s41576-018-0004-3

Lanza, I. R., & Nair, K. S. (2008). Muscle mitochondrial changes with aging and exercise. The American Journal of Clinical Nutrition, 89(1), 467S471S. https://doi.org/10.3945/ajcn.2008.26717d

Werner, C., FürsterT., Widmann, T., PössJ., Roggia, C., Hanhoun, M., ScharhagJ., BüchnerN., Meyer, T., Kindermann, W., Haendeler, J., BöhmM., & Laufs, U. (2009). Physical Exercise Prevents Cellular Senescence in Circulating Leukocytes and in the Vessel Wall. Circulation, 120(24), 2438–2447. https://doi.org/10.1161/circulationaha.109.861005

Wroblewski, A. P., Amati, F., Smiley, M. A., Goodpaster, B., & Wright, V. (2011). Chronic Exercise Preserves Lean Muscle Mass in Masters Athletes. The Physician and Sportsmedicine, 39(3), 172–178. https://doi.org/10.3810/psm.2011.09.1933