You are witnessing the first group of people to reach 50 after the "exercise revolution".
The 60's was all drugs and then the 70's came with body building and jogging.
(
Jim Fixx http://en.wikipedia.org/wiki/Jim_Fixx ,
Arnold schwarzenegger)
Fixx was more influental then even Arnold!!!
Before 1975, if you went jogging people would ask you where the fire was?
No shit, I'm serious.
It was the start of the low fat diet, weight watchers, the explosion of public gyms such
as Bally's, not just jocks but everyone started lifting weights.
The attack against smoking and the first admission that is was actually bad for you.
The new openess about alcohol abuse and treatment.
And last but now least, new and very highly improved sun block and sun burn awareness.
This is just the visual results of people who started these things in their teens in the 70's.