Recent studies show that performing cardio after a meal promotes an increase in EPOC—post-exercise oxygen consumption. EPOC, also known as the “afterburn,” is the number of calories expended after training.
Most of the calories used up in the postexercise period come from—you got it—fat!
So the question is, What’s the best choice for chowing down before a cardio workout? A protein shake made with water or nonfat milk and whey protein, particularly if you do cardio early in the morning, before breakfast.