I really like this exercise for upper body power because it does not give the shoulders the stress that exercises like plyometric pushups do. The reason we used the Dynamax balls is that they are softer and easier to handle when dropped.
A few years later someone on our staff ordered some lighter soft toss balls, probably for the younger athletes we train. The balls sat in the storage closet for a few years. I wondered to myself if we would ever use them. One day I took them all out. We had paid a lot of money for the balls and I was trying to think of a good use for them. Just for the heck of it I threw one of them off the wall in a side twist throw. Normally this throw is our standard rotational core / plyo exercise but is done with a more conventional rubber medicine ball.
My first thought was 'these balls stink, they don't bounce back". In response I threw the ball as hard as I could off the wall to get it to bounce back. It did , but weakly. Suddenly the lights came on. What I had initially perceived as a drawback to the soft toss ball suddenly became a positive. Think about this. Initially we had used rotational medicine ball throws for an explosive core exercise, a core plyo. The fact that the balls bounced back allowed us to get a rhythmic pace and a plyometric effect. The ball coming off the wall forced us to use the core not only to accelerate the ball but, to create a deceleration and a switching effect.
For years I thought that was such a great idea. Then as I mentioned above, I threw the lighter soft toss ball. Suddenly I asked myself "what are we doing rotational power exercises for?" I immediately answered my own question. The goal was shooting harder, or hitting harder in sports like baseball, ice hockey, field hockey and golf. The next question I asked myself was "is the eccentric component of the ball recoiling off the wall important?". The answer seemed to be no. The skill of striking seemed to be a 1 RM type movement that was very powerful but was not repeated multiple times.
All of a sudden these lighter, softer balls were not a mistake but a great new tool. We actually use the lighter Perform Better soft toss balls for almost all of our throws now. In fact, I think that medicine ball slams and side throws are far better with the soft toss balls than with a bouncing rubber med ball.
My advice , if you have a med ball wall and like to use med ball throws in your program for core power order a few Perform Better Soft Toss balls. I like 6-8 lb balls for most athletes but, am even moving to more work with four lb. balls.. Perform Better has also introduced Minis. These are smaller in diameter, easier to handle and are great for kids. For kids a 4 lb Mini ball works great.
In addition the softer ball saves on fingers. We have sprained a few fingers and even broken one or two with our med ball throws. Try them, I think you'll like them.