|Hammerhead land training board - for more about this see here...|
The BOSU ball is actually more wobbly than even my race board, so the legs are firing from the start. I throw the medicine ball at varying spots on the wall so that I'm constantly moving around to catch it. Catching it in one hand looks hard, but while it punishes the wrists and fingers, having the other hand for balance actually makes the exercise easier. Throwing straight ahead and catching against the chest is the hardest work - it nearly knocks me off my feet - but I like to mix it up to get the most varied and functional workout possible.
I train to heart rate (my phone is displaying that on the floor in front of me), but you can do sets of 20 throws, or timed intervals, or whatever feels right for you. I'm finding my heart-rate is up around 80% of MHR if I throw at about this rate. It spikes a lot higher with more extreme reaches and jumping type moves. So I'm getting a great cardio workout while beating up the abs, core, arms and back, and the legs are working hard at keeping balance.
You might want to start with just a football or something until you get the hang of it. A 5kg medicine ball is quite impactful. Another top tip, if you're at a public gym, is to look out for bystanders. Every time, some lycra-clad person will settle down on a mat right behind me to do some kind of yoga moves, seemingly oblivious to how much that medicine ball is going to hurt when I inevitably miss a catch. Finally, make sure you are throwing against a concrete wall. Not a plasterboard stud-wall. Oops...
PS This is not in fact my normal training T-shirt. I normally use the dewerstone Trail Tee, which has a small and subtle logo, but small and subtle is not the way for brand ambassadoring. It's a great workout tee that keeps me cool and is dry enough to wear straight outta the washer. You can check them out here - http://ss1.us/a/Vv3d4Q46