The fat burning zone is the heart rate range that cardiovascular exercisers aim for to burn fat instead of carbohydrates during a workout. This range is typically anywhere from 50-70% of the predicted maximum heart rate. Exercising in the fat burning zone means that you are exercising at a low to moderate intensity level. To find your predicted maximum heart rate, use the following formula:
220 - (age in years) = predicted maximum heart rate
At high intensities of cardiovascular exercise, the body needs to break down fuel very quickly to supply the activity in the muscles. Since it takes the body longer to break down fat than carbohydrates, the higher the exercise intensity, the greater the percentage of fuel coming from carbs. Keep in mind that this process happens on a sliding scale. This simply means that there is no one point that the body is burning only fat or only carbodhydrates. It's always using a mix of fuel sources, but the ratio of fat to carbs can go up or down as exercise gets more or less intense.
Knowing this, theoretically one may think that exercising in the lower intensity fat-burning zone should yield more weight loss than higher intensity exercise. It all sounds great, but is it real or just a hoax?
Exercising in the fat burning zone, or 50-70% of your maximum heart rate, will cause your body to burn more fat as fuel for your workout versus carbohydrates. However, this really doesn't make a big difference in the long run of your weight loss journey. Why? Because it really doesn't matter what type of calories are burned when you're trying to lose weight. What really causes weight loss is the total number of calories burned. You'll burn more total calories at higher intensities and that's what matters most.
Experts recommend exercising at 70-80% of your maximum heart rate. If you're a beginner, it's perfectly fine to exercise at a lower intensity and increase it slowly. Interval training is a great way to slowly increase the intensity of your cardio workout. But once you're in better shape, aim for higher intensity workouts for more total calorie burn, and therefore, more weight loss. You'll also make bigger strides in cardiovascular fitness by exercising at higher intensities.
When it's all said and done, in order to lose those extra pounds, total calorie burn is what matters. Reducing calories by following a healthy, balanced diet, and participating in a higher intensity exercise program is the best way to burn the most fat. It may not be what you want to hear, but it's the truth of the matter!