Moving heavy weights mainly activates fast-twitch muscle fibers. So does performing explosive movements, like throwing a medicine ball or jumping onto a box. Last June, a study in the Journal of Applied Physiology found that explosive muscle contractions may be more effective for increasing strength than slower contractions done with heavier weights—i.e., traditional weight training.
We say you need both—but the magic lies in sequencing. If you start your workout with explosive exercises, you can key up your central nervous system to recruit more muscle and boost performance on heavy lifts.
On upper-body days, throw an eight-to 10-pound medicine ball at the wall. Pick it up and repeat. (If you can’t use a wall, throw the ball at the floor). On lower-body days, find a box or step that’s moderately challenging to jump up onto. Stick the landing, then step down. For both exercises, do three sets of five reps, resting a minute between sets. Then go on to bench presses, squats, or other barbell exercises.