The Master Cleanse Diet consists of avoiding solid foods in favor of a beverage made with lemon juice, cayenne pepper and maple syrup. A fad diet, it's not recommended, because it isn't nutritionally sound. It contains almost no protein or fat and only minimal amounts of any essential vitamins and minerals. Speak with your doctor before attempting this diet or exercising while following it.
This diet contains of only 650 calories per day, well under the recommended minimum of 1,200 calories per day for women and 1,800 calories per day for men. Due to the low number of calories allowed on this diet, it may not be safe for you to exercise, according to an article on the "U.S. News & World Report" website. The lack of calories and nutrients can also cause adverse effects, such as headache, lethargy, fatigue, aches and pains, so you probably won't feel like exercising anyway. A healthier weight loss option would be to exercise at least 2 1/2 hours each week and follow a sensible, balanced diet including lean protein, whole grains, fruits and vegetables.