This diet is extremely flexible. If you would like to exercise then you need to offset calories burned with an increased consumption of calories. For example: If you run and burn 300 calories then you need to balance that out by consuming 75% of those 300 calories (or an additional 225 calories consumed). But you may only eat from the approved proteins and vegetables. No extra fruit. It is important to note that vigorous exercise will slow your weight loss. You will lose inches, but your overall weight loss will be noticeably slower.