[snowwrestler]

If you had followed the exact same fitness regimen when you were 25, you would have seen better results: higher speeds, more endurance, shorter recovery times, etc.

That’s why I mentioned sports: even people who have worked out their whole lives, at the top of their sports, see declines in physical performance as they age.

Congrats on getting in shape. Relative improvements in physical fitness are beneficial and possible for many people. But it doesn’t reverse aging.

[Earw0rm]

Speed and recovery? 100%. Endurance, not so much.

Recovery times are shortest in children - and become very significantly longer even at ages where maintaining muscle mass isn't too much of an issue. Maximum speed peaks with strength in your mid/late 20s & declines from there. Endurance seems to carry on increasing in to the late 30s & declines very slowly, plenty of ultrarunners, Audax cyclists and triathletes in their 40s/50s.

[gratalis]

Obviously had I started from an earlier point, I may have achieved a higher overall peak performance level but that isn't the point I was addressing. Nothing reverses entropy that we know of but that isn't the point either. The point is that saying "you can’t do at 50 what you could do at 25" is patently wrong. I point this out simply because many people have an incorrect perception of their ability to alter their fitness via lifestyle changes.