Can I lose weight by exercise alone?

Exercise, while critically important to your overall health and well-being has a very specific energy demand that is measurable. What this means is; whatever you choose to do as far as exercise is concerned costs your body a specific amount of calories to do it. Thirty minutes of cardiovascular exercise can cost anywhere from 150 to 350 calories depending on what you do, how much you weigh, and the intensity at which you do it. If you simply replace those calories that you just burned with an energy bar or a large supplement shake and then continue on eating the rest of the day as you normally would, then while you will be better off because of exercising your weight loss will be negligible or nonexistent. The key to healthy weight loss is combining caloric restriction with additional caloric expenditure. This means healthy reduced eating and healthy exercise.