By: Ergolog

If you want to live longer you have to exercise more; nearly all studies show this. But if you don’t want to stop there, you can choose to do forms of intensive physical exertion that boost your maximal oxygen uptake. Researchers at the Kronos Longevity Research Institute [] discovered that the fitter you are, the more protective antioxidants your body makes.


The researchers studied two groups of people in their sixties: 37 fit 60+ and 35 unfit 60+ subjects. The first figure below shows the difference between the two groups.

When the researchers analysed samples of blood taken from the elderly subjects when at rest, they noticed that the concentration of 8-hydroxy-2′-deoxyguanosine [8-OHdG] was lower in the elderly that were fit. The higher the concentration of 8-OHdG, the more damage to your DNA [second figure below].

The concentration of 8-hydroxy guanosine [8-oxo-G] was also lower in the fit subjects in their sixties. That means that the RNA molecules in their cells incurred less damage. Both 8-oxo-G and 8-OHdG are produced through reactions with free radicals.

The researchers then did a test in which they constricted the blood flow to the lower arm for a moment, and then let it resume. This process leads to the release of large amounts of radicals.


The figure above shows that the concentration of F2-isopostanes [F2-isoP] increased when the blood supply was restricted, but that the increase was less in the fit 60+ group. Isoprostanes are created when free radicals damage cell membranes. The lower increase in the fit 60+ group means that their bodies were making more natural antioxidants.

Aging is to a large extent the work of free radicals, and these are a by-product of cells’ energy generation. However, the body also makes molecules that deactivate free radicals. The research done at the Kronos Institute suggests that the body makes more protective molecules – and therefore ages more slowly – the fitter it is.


“Encouraging older adults to not just be ‘physically active’ but to be ‘physically fit’ may be an effective strategy to lower oxidative stress and oxidative damage and hence to improve long-term health outcomes”, the researchers conclude.

Age (Dordr). 2012 Aug;34(4):969-82.