When I was in school in Texas, back in the 70s, all the way down into the junior highs, we had split classes, but they actually occurred in the same time periods with the non-athletes. Most athletes were scheduled for PE in one of the last two class periods of the day in junior high, which allowed them to either "warm up" before practices ... usually read as light lifting or conditioning ... or practice started in your PE period if it was the last period of the day, so you had extended practices. In the off-season, the athlete portion of the class did weights and conditioning. The other part of the class was the non-athlete folks. They tended to get to do the fun stuff like bombardment, shooting hoops, etc. When the weather was nice, they got to go outside and do soccer, football, track-like activity, etc. while we either remained inside on the weight circuit or went outside to the obstacle course for conditioning or the track for the really boring conditioning.
The weight circuit because it was situated such that you could see what everyone else was doing that weren't lifting. As you made your way back to the front of the circuit, the first 3-4 stations gave you a full view of the gym and all of the fun stuff the other guys were doing while we were stuck lifting and conditioning.