For me it boils down to the SAID principle. What is the outcome? How does it transfer into real life? What training adaptation are we trying to achieve. If it is just for fun, then it is just for fun.
On another note, I was running with a medicine ball for NINE MONTHS!!! However, after I gave birth I gave that up! 8))
I use this as exercise in some of my programming and personal conditioning. Think it serves as a great teaching tool also.
In a class setting things can get sticky if not space appropriate & on what kind of time/timing conditions. I feel it translates well in general exercise program as the participant is always in control of their activity (reality) & always under close observation for the major deal breakers:
1. BAD FORM
2. PERFORMANCE OF
I do use this exercise in my boot camp classes as well as on my 1-1 clients. I don’t think it’s appropriate for all ages, but it’s a case by case option. What you could do, is to have this option on the table when you are teaching classes for those who are more advance and they would like some extra challenge. You will however need to demonstrate the proper technique, so who ever decide to use the medicine ball should know what to expect. Also, not all sizes and weight fits all. You will need to have a variety of sizes and weights for the medicine balls. I actually prefer the ones with the handles, because it’s easier to handle and carry them while running.