Seems like a pretty small effect - if I'm 58 and I have the brain of a 57 year old, and to achieve that I did an entire year of exercise (as was done in this study) ... you'd have to evaluate it against many other things to decide if that was really the easiest way to achieve that result.

I'm always suspicious of small effect sizes even when they are statistically significant. It just seems like so many confounders could bring about the effect. Here I'd wonder if just the mental challenge of achieving that sustained exercise over a whole year was responsible, since generally speaking, any mental challenge you undertake on a regular bases improves overall cognition.

They try to argue their way around this:

> "Even though the difference is less than a year, prior studies suggest that each additional 'year' of brain age is associated with meaningful differences in later-life health,"

But it just begs the question, if you think that then go measure those things with your study.

Of course I'm not in any way arguing against exercise. Adding at least a baseline level of exercise into your lifestyle is the most impactful health intervention anybody can do after age 40 I believe.

There's also heart muscle elasticity:

https://www.ahajournals.org/doi/10.1161/circulationaha.117.0...

and reduced dementia risk:

https://publichealth.jhu.edu/2025/small-amounts-of-moderate-...

They do not make the claim from the title. Given that the effect is small, it might just be that brain-PAD is sensitive to other factors than age, e.g. exercise. As a matter of fact, this study is decent aupport for that hypothesis.

https://www.wendysuzuki.com/exercise-research

The general consensus should just be exercising is good for you, that's it, done.

The benefits of exercise against aging, mental illness, etc are numerous and well documented. Everybody should do it.