I like to work on my core while I do video games. How? I use a wobble board or balance pads and play a game on the Wii. The volleyball on this game is great: to add more upper body work and to make the game more difficult I play two players, one in my left hand and one in my right. At first this is difficult-- you must think fast and be aware of which player is going to have to hit. What is great is that it really gets like real volleyball-- you can do overpass kills and block kills! Your front player near the net, if he's quick, can spike when the other team bumps over. I know that my balance and core strength has improved immensely, and because it takes so much concentration I don't think about how I am exercising. I also do some of the game in a squat position to do leg strengthening. This is just so much fun. I also do the balance board with the horse jumping, water tube racing, and skiing. I don't think the wall climbing or shooting or dodgeball are as conducive to using the balance board.