Calories burned during strength training

bsmith404

So I wear a GPS watch to run and the other day I ran 5miles and I burned 544 calories and then I came home and switched my GPS watch to my heart rate monitor, since my other watch doesn't work indoors. So anyway I do an hour of P90X legs and back. I haven't done weight training in 6 months because I was concentrating on running but i'm back to weight training. Well my hrm said I burned 644 calories. Does this sound right? It didn't to me so I logged in a little less than 1/2 of that.

How much do you burn in an hour of strength training? I know P90X is intense as my whole bottom half is hurting today. Hurts to even walk:)