A 145,000-Person Study Just Linked Exercise to a Lower Biological Age. But There's A Catch

I’ve spent a few posts now picking apart biological age tests, mostly because the epigenetic clocks behind them don’t agree with each other and were never built to judge one person. But when a massive new study lands claiming exercise lowers your biological age, it’s worth asking: is this just click-bait or is there something here?

Turns out, it’s a little of both.

A new study in The Lancet Healthy Longevity looked at 44 studies and 145,465 people for anything linking physical activity to DNA methylation clocks, the blood tests that estimate biological age. It found that more physical activity was indeed linked to a lower biological age, but only on two of the four clocks tested.

Which is sort of the issue I've raised. Exercise shows up as a real signal on some biological age tests and vanishes on others, which tells you something about the clocks as much as it tells you about exercise.

This evidence is almost entirely cross-sectional, meaning researchers compared different people at a single point in time, not the same people before and after they started exercising. That means you can’t say exercise caused the lower score. It’s a correlation, not a causation.

Truth is, testing actual physical capacities (your cardio, your strength, your gait, your balance, your body composition, your reaction time) can detect changes in ways you can measure directly, without needing a blood draw to catch up to what your training is already doing. Movement is the lever that actually works on aging.

So keep training, obviously, because the exercise-is-good-for-you conclusion was never in question. But don’t wait on a biological age test to tell you it’s working, and don’t let an inconsistent blood result talk you out of progress you can see and measure directly in how you move.

If you're interested in results you can actually see, book an Activate Your Age assessment and measure what your training is really doing - or could be doing.