I draw upon anecdotal experiences. I played on a team that had a 10.28 100 meter dash guy at QB, and a 10.35 at tailback and a 10.7 guy at fullback, along with a couple of 10.7- 10.8 guys at the wide receiver positions. We had offensive and defensive linemen who ran sub 4.6 in the 40 and we had a lot of guys benching over 400 and a couple close to 600.

I don't know of a single FCS team in 2018 that can actually match that...and if any FBS teams can, you can count them on one hand...

The kids are demonstrably bigger....but I'm not seeing the commensurate gains in speed and strength, proportionately, with the obvious gains in size.