Regarding the post about the gowearfit calorie burn being really low - I wear both a bodybugg and a HRM when I work out (yup, uber geek here) and my bugg always calculates a significantly lower calorie burn for all workout types except running and walking, compared with my HRM. I don't think it means you are actually burning less calories - I think it is a function of how the bugg and gowearfit work.
But you can check it out for youself, if you have a heart rate monitor, try wearing that when you do plyo legs and compare it with what the hrm says for a run - and see what results you get.