Fat Burning Vs. Cardio Exercises

Jupiterimages/Photos.com/Getty Images

When you get on a treadmill or any other cardio machine, you will often find a list of preset programs, such the fat burning and cardio workouts. While you'll get some of both no matter which you choose, the results of each workout differ somewhat. Understanding what the preset programs mean can help determine whether to select a fat-burning workout or a cardiovascular workout.

Fat-Burning Zone

The fat-burning zone is when aerobic exercise is performed at a lower-intensity level in which fat oxidation rates are at its highest, between 55 percent and 72 percent of maximum heart rate, according to Jack H. Wilmore and David L. Costill, authors of "Physiology of Sport and Exercise. When you exercise at a low-intensity level, a larger percentage of calories burned are coming from fat stores rather than carbohydrate stores. Exercise at this intensity level is also referred to as steady-state cardio or long duration cardio, because it can be performed for a long time.

Cardio Zone

The cardio zone is aerobic exercise performed at a higher intensity level. The cardio zone is between 70 percent and 85 percent of maximum heart rate, and at this intensity, a larger percentage of calories burned come from carbohydrate stores rather than the fat stores. The purpose of exercising at this intensity level is to improve aerobic capacity and endurance. However, exercise at this intensity level for an extended period will burn more calories than exercising at a lower intensity.

Maximum Aerobic Power

Maximum heart rate is determined by subtracting 220 from your age. From that, you can determine your target heart rate zone by multiplying your maximum heart by the percentage you wish to be in. For example, a 30-year-old woman who wishes to be in the fat-burning zone would calculate her MHR like this: 220 - 30 = 190 maximum heart rate. Multiply 190 by 55 percent to get 104 beats per minute; multiply 190 by 72 percent to get 137 BPM. The target heart rate for a 30-year-old woman in the fat-burning zone is 104 to 137 BPM.

Bottom Line

Although the fat-burning zone uses a larger percentage of fat as fuel compared to the cardio zone, it does not burn as many calories, therefore it won't result in as much of a weight loss. Higher-intensity exercise also has a more significant effect on keeping your metabolism elevated after your workout, which adds a few more calories to your deficit, according to the American Council on Exercise. However, higher-intensity exercise is harder to sustain for an extended period. Include a combination of both low-intensity and high-intensity aerobic exercise into your fitness routine to achieve optimal weight-loss results.