I really don't know about losing stuff from youth. When I was teenager, and young adult, I was in awful shape. Skinny, soft, weak beyond belief. I couldn't deadlift an empty bar. So envious of the athletes, the strong men, they were so far ahead of me. Today in reasonable shape, still not as strong as I want, but feeling much better. I can only take everyone's word for it that things come down from a better level. Can only imagine how easy kids have it to gain strength.
Oh, and Snapper, you've certainly come a long way. And I'm thrilled you encourage your kids to be in sports, too.