Big calorie difference in Month 2 Insanity workouts?

ebarish

I did Max Interval Circuit yesterday and burned about 432 calories, but I did Max Interval Plyo today and only burned 345. That's almost 100 calories less! Is that normal, or am I doing something wrong? I feel like there shouldn't be that big of a discrepancy between those two workouts. What do you guys think and what have your experiences been? Thanks so much!