I think kids back then just did stuff on their own or worked....kids these days are out in the heat a lot, its just in more organized settings, summer workouts, 7on7, private 1v1 training etc....its different but most HS Football players are on campus 3-4 hours a day much of the summer, lifting, running, doing sport specific work etc...that more than adds up for the time "lost" not doing two-a-days