Don't fall for the mythical fat burning zone listed on the heart rate monitor of your favorite cardio machine at the gym. Although you will burn a greater ratio of fat to carbohydrates in this moderate heart rate zone, you'll burn more energy overall -- and more fat in the long run -- if you work out at a more intense pace. You can, however, trick your body into burning fat with a few simple habits.
Drink ice water. A process known as thermogenesis burns energy to raise the temperature of ice water to your body's temperature. A study conducted by German researchers published in the December 2003 "Journal of Clinical Endocrinology and Metabolism" found that a person's metabolism increases by 30 percent following the consumption of about two 8-ounce glasses of water and remains elevated for about an hour.
Reduce the total number of calories you consume. Your body burns fat when you use more energy than you consume through eating or drinking. The easiest way to achieve this energy deficit is through calorie restriction. Burning off calories though intense cardiovascular exercise also contributes to the energy shortage.
Add intervals to your cardio workouts. After only two weeks of aerobic interval training, participants in a 2006 study published in the "Journal of Applied Physiology" increased their fat oxidation during exercise by 36 percent. One possible explanation for this is that your body requires oxygen to metabolize fat, and study participants' cardiovascular fitness and oxygen intake increased during the study. Thus, they had greater oxygen available for fat metabolism. Make intervals work for you by using the rate of perceived exertion scale, or RPE. Exercise at about 8 out of 10 on the scale for about two minutes followed by two minutes at about 3 or 4.
Stop eating two to three hours before bedtime. While you sleep, your body still needs energy to maintain a beating heart, regulate breathing and carry on various other functions. When you stop eating well before you hit the hay, your body reaches to stored fat for its energy needs. Although the energy requirements during sleep are lower than when you're awake, all of that energy comes from stored fat.
Build lean muscle tissue to increase the fat burned during sleep. Muscle burns more energy than fat, even while you're at rest. You can achieve hypertrophy -- an increase in muscle size -- by lifting heavy weights three days each week. Choose exercises that work all of your muscle groups, and perform three sets of 12 repetitions of each exercise.