For you fitness types...Something I always wondered about. Especially since I track my food intake pretty religiously using MyFitnessPal app. I see riding hard as more of a cross between lifting light weights and cardio. It's more involved than just plain cardio, so wearing a HR monitor might not be a completely accurate measure. Most calorie counter apps don't give you credit for lifting, but of course when you lift there is the "after burn" of the increased metabolism throughout the day, plus the actual calories burned doing the work. For lifting I usually credit myself 250 or so for a one hour session, where I maybe do 6-8 exercises, 4 sets per exercise. I weigh 190-ish. MyFitness Pal has a 'Motorcross' under cardio, about 300 calories per hour, for my weight anyway. I don't eat much on race days, usually because I am so busy drinking fluids. Last weekend it was so damn hot, I drank about 1.5 gallon of (mostly water) fluids each day. With that much fluid in me I had to force myself to eat. Sunday night I fixed that with a bacon cheeseburger and fries, of course.