This is a great workout game. If you actually try and play this game for the workout, these calorie based achievements should come naturally.
If you are looking for a quick way to get them all, see the 10k calorie achievement guide for suggestions on how to get these faster.
Chances are you're going to burn around 600-1000 just to get the other non-calorie based achievements, but anything beyond that you'll either need to continue doing a workout or use the tactics mentioned in the 10k guide.
I find that when working out for real, I'll burn about 200 or so per 30 minute session. In my opinion this is a great way to get a relatively quick workout and slowly work towards the achievements.