You must learn not to want what you should not have. Muscles cannot turn to fat, contrary to popular conception, that if you stop exercising regularly, muscles will turn to fat. They simply do not have the physical capability of changing from one type of tissue to another. No diet aid can firm you up-only exercise can. Muscle burns calories even at rest, while fat tissue is virtually dead weight.
Muscles burn fuel.
When you lose muscle tissue, your ability to metabolize the calories you consume, is decreased. If you switch back to normal eating patterns at the end of the diet, you may actually gain the weight back faster than you lost it. Do those vigorous exercises that you feel good doing. You can exercise anywhere. Do exercises that are progressively stressful or resistant.