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.