activity points - calories burnt question

Hello,

I have a new game for my xbox kinect, where I have a personal trainer and it's very spangly and fancy. It scans my body and works out my calories for each session.

Does anyone know if it's possible to work out activity points on calories burnt? On this game I do a wide range of activties and never really know the exact time that I am doing those activities for. So kinda of hard to track.

Does anyone know if you can work out activity points on the amount of calories burnt? I have figured out;
50 calories = 1 activity point

Does that sound about right?

Thanks all