Myth behind the 'Fat Burning Zone!'

I constantly hear about how you will burn more fat calories if you keep your heart rate low, in what is called the 'fat burning zone.' Low meaning 60-70% of your maximum heart rate which is equal to 220 minus your age. For example, my fat burning zine is: 220-31 = 189. 189 is my maximum heart rate. 60% = 113.4 and 70% = 132.3 so my zone is keeping my heart rate between 113.4 and 132.3. My heart rate usually averages around 160 while working out, much much higher than the dedicated zone!

The idea behind the fat burning zone is that if you keep your heart rate in the designated area, you will burn more calories for energy from fat. The myth comes from the fact that your body is burning a higher percentage of calories from fat; around 50% of calories. If you were to work out at a higher intensity, 70-90% of your maximum heart rate, you will be burning a lower percentage of calories from fat (around 35-40%)and more from carbohydrates, but you are burning more calories overall. This total caloric burn is what is most important because it still ends up averaging more calories burned from fat even though the percentage is lower because the overall burn is higher.

So, for example, my typical workouts burn about 400-450 calories overall, in a 30 minute period. Using both lower numbers to get the minimum amount burned: 35% of 400 is 140 fat calories burned. If I kept my heart rate low, in the fat burning zone, I would burn only about 200 calories (at most) in that same amount of time, and 50% of 200 is only 100 fat calories burned. So as you can see, you are still burning more fat overall doing higher intensity workouts rather than lower intensity or 'fat burning' workouts.

Case in point, the whole 'fat burning zone' for heart rate is really misleading and will not help you reach your goals. I always recommend using a heart rate monitor and keeping track of your heart rate throughout your workouts, aiming for at least 70% of your maximum heart rate.