You can find medicine balls, those spherical, heavy objects traditionally made from leather, mostly found tucked in the corner of a gym covered in cobwebs. Newer versions are made of rubber or vinyl, filled with air, water or a gel and vary in size from a tennis ball to a small beach ball.
Unlike the machine training rage of the 90s that concentrates on isolating muscles in a specific plane of motion, medicine ball training promotes the integration of muscle actions and allows people to condition their bodies in all planes of movement.
Simply, you can do things with medicine balls that just aren’t possible on machines, or even free weights!
Medicine Balls Open Up New Possibilities
For example, suppose that you want to develop explosive strength and power for throwing a baseball. Following the Principle of Specificity of Training, you’ll get the best results when you overload the muscles in the exact pattern of movement.
However, most gyms will not appreciate it if you start to throw dumbbells across the weight room!
Compare this to training with a partner or rebounder and a medicine ball. In this case, using an exercise like the medicine ball throw would meet the requirements of the Principle of Specificity of Training (see Figure 1) and improve your throwing power greatly.
Or, if you’re training to achieve quick, explosive movements, most weight machines can be tricky, dangerous and generally not very effective. Remember what happened last time you did an explosive hamstring curl on a machine? Is the leg curl machine still in one piece, or is there a hole in the ceiling of the gym?
Using a medicine ball can be more effective and you don’t necessarily have to lie on your stomach either (see Figure 2 for the standing dynamic leg curl).
Explosive Resistance Training With a Medicine Ball
The fact is that weight machines are neither designed or sensible for explosive high-speed resistance training in ways that medicine balls are!
This sort of explosive training is extremely important. Explosive medicine ball training integrated into a bodybuilding program will give your nervous system a jump-start.
I have seen weightlifters increase their bench press by as much as 7 kilograms (about 15.5 pounds) in two days, after performing explosive push passes and kneeling push passes in just one session (Figures 3 and 4).