Posted by scoozna
Can anyone explain to me the concept behind doing the medicine ball right after the dumbell presses?
You'd probably need to ask him or the trainer for exactly what they are trying to accomplish, but there are a couple of common training philosophies that would explain doing that.
1) Most likely he was trying to build "explosivene endurance" by forcing himself to perform speed exercises while his muscles are fatigued. This is similar to running sprints at the end of a football practice and it's pretty common in combat sports training. The goal is to have the fighter be able to keep his speed even when muscles are tired. The heavy dumbell presses are temporarily fatiguing the same muscles he uses to throw the ball into the air. Using the heavy weight for low reps is going to allow him to both build more power and to recover faster than if he fatigued those muscles by doing 100 pushups or just throwing the ball into the air for many reps.
2) It's less likely the goal here, but this also follows the old "superset" weightlifitng strategy to burn out your muscles more completely than doing individual sets. The idea is to make all of the reps difficult but possible which involves using heavy weight when you are fresh and then switching to lighter weights when you are fatigued with little or not break between. (note that the press of the medicine ball was essentially the same motion as the press with the heavier dumbells). Some bodybuilders believe this activates a higher % of muscle fibers than would be the case if multiple sets with a single weight were used.