If you are, remember, this is still a calorie burn. You've been asking your body
to reverse gears in a pretty short time frame
. It's important to get good nutrition; make sure you're eating good carbs and protein - whole grains and peanut butter, nuts, eggs, and lean meats are all good sources of protein. You can also add supplemental shakes, like Ensure, to your diet to give you a calorie/protein bump. They actually taste pretty good!