Significance

• Fat can accumulate between muscles, on top of muscles and around the internal organs. Obesity-related illnesses overwhelm hospitals and the medical bills cost hundreds of billions of dollars annually in the United States alone. One method of battling the bulge is to burn fat during exercise using target heart rates.
  
  

Function

• The heart rate at which an individual burns the highest percentage of calories from fat is known as the aerobic base. The aerobic base is typically anywhere from 40% to 70% of an individuals' maximum heart rate (the easiest method of guessing target heart rate is to subtract your age from 220). At this aerobic base, an individual burns 50% to 70% of calories from fat. In comparison, when exercising at the maximum heart rate, individuals burn less than 5% of calories from fat.
  
  

Considerations

• Individuals may not always have a heart rate reading available when exercising. Use a feeling measurement in this case, such as the "talk/sing" test. You are burning a high percentage of calories from fat if you can sing. If you can sing, you will not feel any noticeable burn in the muscles (but you should be working up a sweat). Most individuals will begin burning a higher amount of glucose (sugar) and less fat as singing and talking become more difficult during exercise.
  
  

Expert Insight

• Let's say a female walked for 30 minutes in the fat burning target heart rate. She felt no muscle burn and could sing while walking. In those 30 minutes, a 130-pound woman burns 150 calories, and 70 calories burned are from fat. Now let's say the same 130-pound woman walks 30 minutes with a higher heart rate, where she felt a slight muscle burn and could not sing, but could still talk. This time she burns 205 calories and 85 calories from fat. Just by working a little harder, the women burned 15 more calories from fat and 55 more total calories. The bottom line is that when performing cardiovascular exercise, if you want to burn fat, you should be able to talk but should not be able to sing.
  
  

Benefits

• Weight loss is all about calories in versus calories out. Increasing caloric expenditure during workouts can accelerate fat and weight loss. As the body becomes accustomed to exercise, it burns more fat at higher heart rates while simultaneously enjoying all the other benefits of exercise. Be consistent with exercise habits. Keep moving. Work on improving your fitness levels, and all the fat loss benefits will follow.