In humans, ageing is accompanied by a decrease in fitness. Although this gradual process is often not noticeable in everyday life, under physical strain, we often feel we have less staying power than we used to. The ageing process also leads to a decrease in the activity of important control enzymes called sirtuins. But is there a connection between fitness and sirtuin activity? According to a scientific review published in June 2019: yes.
Take the example of a used car. Based on the year of manufacture and mileage, you can draw conclusions about its condition. Increasing age and wear inevitably leave traces. The same can also be said of humans, and we can begin to draw conclusions about the state of our bodies. Unfortunately, it is not quite that simple here. A crucial difference is that, unlike vehicles, we humans (and biological systems in general) can combat our decline. On one hand, we can react to and actively protect ourselves against external stress factors. On the other hand, our body can repair certain types of damage itself. Sirtuins, a group of endogenous enzymes (SIRT 1 to SIRT 7), are involved in this repair activity.
A scientific review published in June 2019 highlights the importance of movement for sirtuin activity. For the review, the researchers surveyed the currently available studies on sirtuins and movement and focussed on the two best-studied enzymes of the sirtuin family: SIRT 1 and SIRT 3. After analysing the study material, they confirmed that physical activity stimulates the formation of sirtuins in skeletal muscle. The effect depends on the type of movement.
A one-off physical load activates the SIRT 1 enzyme, which stimulates the development of new body structures (biogenesis) and the oxidative capacity of the mitochondria (cellular powerhouses). Multiple training sessions also activate the SIRT 3 enzyme. In addition to biogenesis and the oxidative capacity of the mitochondria, the production of the endogenous energy storage molecule ATP is also stimulated.
According to the review, different training methods stimulate different enzymes of the sirtuin family, which in turn stimulate different metabolic pathways. However, the various sirtuin pathways always seem to have one thing in common: they improve the health of our mitochondria – the tiny cellular powerhouses that are important for fitness at every age. As the saying goes: you’re only as old as you feel.
References:
Vargas-Ortiz, K. et al. 2019. Exercise and Sirtuins: A Way to Mitochondrial Health in Skeletal Muscle. Int J Mol Sci. 20(11). doi: 10.3390/ijms20112717.
Sinclair, C. A., Guarente, L. 2006. Schlüssel zur Langlebigkeit [The Key to Longevity]. Spektrum der Wissenschaft. 34–41.
