A friend of mine asked me the following today:
"If it is all about calorie in, calorie out then why not just lower calories the same amount that you would burn by doing the cardio and therefore not have to do the cardio?"
I have to admit I was embarrassed not to know the scientific answer why.
One could also as: if it is all about calorie out, calorie in, then why not just eat all the carbs and fat that you want as long as you eat less calories that you burn?
But this answer has to do with macronutrients and there effect on the body (ie - insulin spike, nitrogen balance, etc) and how that effects the weight that will be chosen to burn
So what is the answer? does it matter?