Arm and leg sensors will not work, used new batteries
So if you are still wondering--or for anyone else looking--I MAY have an answer. It should help someone, anyway. I got my game used from Game Stop. It came with FOUR sensors,which was weird, but whatever. Until I tried using it. First, I realized I didn't get the USB connector. Ok, went back and got that. Then I tried syncing. First one didn't work, so I tried the second arm/heart sensor band. It worked! Then the leg sensor. I tried that stupid thing for more than 30 minutes, unsynced my remote by accident in the process, and generally got my heart rate up just sitting there getting annoyed. Finally, something I read struck a chord. So I pulled the batteries from every sensor and looked at the label underneath. Sure enough, only 1 of the 4 sensors was for the Wii!! The other 3 are PS ones!!! AUGH! I called Game Stop and they found a leg band for me, which I will be picking up tomorrow. So the point is, if you got it used, check the label!