I did two. :P Will managed 21. I will say that I haven't done any upper body or core exercises in several months (bad me!). I'm trying to armtwist Will into giving it a shot, but if he won't, maybe I'll use you as my conscience and see if I can stick to it. My left wrist is prone to carpal tunnel so I can't guarantee it will allow me to do this, but ... I would love to improve my core strength to help with running and general fitness and maybe this is the kick I need.