Aerobic Exercise vs. Fat Burning Zone

When you're exercising it's helpful to get feedback from your body. One of the most accurate sources of feedback is your heart. You can monitor your heart rate zones to target your workouts toward specific goals. This could include improving your aerobic fitness, burning fat or even doing both simultaneously.

  1. Fat Burning Zone

    • The fat burning zone is the heart rate range in which your body maximizes fat oxidization, meaning that it consumes the most fat as a fuel source. In this zone about half of your calories burned will come from fat stores. According to researchers at the Health and Human Performance Laboratory at the University of St. Thomas, the fat burning zone is in the range of 67.6 percent and 87.1 percent of your maximum heart rate. This range will vary from person to person, however the researchers note that you can be reasonably confident that your maximum fat burn will be between 60.2 percent and 80.0 percent of your maximum heart rate.

    Aerobic Zone

    • The aerobic zone is the heart rate zone where you develop your cardiovascular fitness. According to running coach Brian MacKenzie, the aerobic zone is between 70 percent and 80 percent of your maximum heart rate. But researchers at the Health and Human Performance Laboratory found that this zone is even broader, ranging from 58.9 percent and 76.2 percent of maximum heart rate.

    Overlap

    • The aerobic zone and the fat burning zone are not mutually exclusive zones. The former is a training zone, used for improving aerobic fitness, while the latter is used to assess your body's energy sources. These two zones actually overlap, meaning you can do a workout that is in both the aerobic and fat burning zones. As the researchers at the Health and Human Performance Laboratory put it, you can "simultaneously meet the requirements of the American College of Sports Medicine for both aerobic fitness and weight control."

    Calculating Maximum Heart Rate

    • To train in either or both of these zones you need to know your maximum heart rate. A simple method for estimating it is to subtract your age from 220. For instance, if you're 30 years old then your maximum heart rate would be 190. If your heart rate is 133 when you're working out, for example, then it would be at 70 percent of your maximum -- falling into both the aerobic and fat burning zones.