The stairs test.

My honest benchmark isn't a stopwatch, it's whether I can go down the stairs normally the morning after a long run. For two years the answer was no. Now it's usually yes. That's the whole review.

With three kids, the morning after a twenty-miler isn't a rest day, it's a school run. Anything that shortens the recovery window has an outsized effect on the rest of my week.

I'm not chasing a PR anymore. I'm chasing being able to keep doing this for another twenty years.

Individual results vary. This is a personal experience shared voluntarily, not a clinical outcome, and it is not typical or guaranteed.