I'm going to take a wild guess here and say today's athletes aren't that drastically different than my crew when we were in our teens and early 20s. Except they have more specific workouts - still you want to catch up with your boys before the season when everything you do is planned for you.
We probably would have spread the heck out of it because a bunch of us would show up a week before the official report date: Those NAIA Days went something like this in 1970s Dodge City, Kansas:
Meet at noon after breakfast at the High School field, run agilities and sprints, do position drills, and sweat off the night before.
Head to the Sandpit and spend an hour in the water checking out the bikinis.
Afternoons the QB and WRs would throw, DBs cover. The line would play touch football.
Early evening go to Big Nosed Kate's or Wyatt Earp Cafe and eat (still) the best Mexican food I've ever had
Finally, Go rage till the bars closed. It proved to be a bonus when one of the Seniors who took me under his wing when I was a freshman, became a local cop.
And in our locker room - where guys during two a days would bet to see who could get their sweat-drenched practice jersey to dry and stand up on its own- we had great herd immunity