[nonameiguess]

This needs to include not getting injured as well. I worked out plenty in my 20s, but was also reckless as hell, and lost most of my 30s to severe spinal degeneration. It's not too late in your 40s, though. It took about six years, but even after spending most of a decade unable to consistently put my own shoes on and ending up with ten screws in my spine, I'm still lifting just about everyday and putting up lifetime PRs. To be clear, I'm not saying those are huge numbers, since I was more of an endurance athlete in my 20s and only lifted to have a solid strength base for longer-duration activity, but even so.

Granting here, I'm sure it's definitely easier to resume old habits after injury recovery than to start completely fresh, so yeah, still start young if you're young. But if you're not, it's never too late until you're in the ground.