Many people are overly concerned about the type of calories they are burning during exercise. Let me first just say that it is important to exercise in ALL heart rate zones. Maybe not all on the same day. I mean, you have to mix it up a bit, have some semblance of a plan in your weekly or monthly routine. But if you are obsessively trying to stay in the fat-burning zone, not only are you doing yourself and your body a serious injustice, you just don't get it.
Okay, first let's remove that big white elephant from the room: There's no such thing as a fat-burning zone. There, said it.
I'll explain in a minute why this is a myth, but first let me say that exercising in this zone, which is typically defined as 65-75% of maximum heart rate (MHR) should definitely be a part of your training repertoire. And when I say training, I am still referring to you folks out there who may not be training for athletic competition, but just want to look and feel good. The 65-75% MHR training zone is necessary to build an aerobic base and to aid in recovery. You can't go hard day after day, not only will you burn out quickly, but you will make yourself more vulnerable to injury and respiratory infections. All people, whether they're elite athletes or your average Joe (or Jane) need to practice the PROS (progression, regularity, overload, and specificity), something that I discuss in my book, DotsoFit Health and Fitness, available at Amazon.com.
Below is the table that everyone came to this website to see. Now, skip to the bottom of this post if you want to see why the fat-burning zone is a myth.
1 Respiratory Exchange Ratio (RER) is the ratio between carbon dioxide production (VCO2) and oxygen consumption (VO2). RER = VCO2/VO2
2HR = heart rate, 3RHR = resting HR, 4MHR = maximum HR
If Joe had doubled his speed to 6 mph for 20 minutes (this is a slow jog, a 10-minute-mile pace), Joe would have burned 46% of his calories from fat and 54% from carbohydrates. However, because Joe is working harder, he is burning more total calories, and the actual numbers come out to be about 90 calories from fat and 104 calories from carbohydrates.
Do you get it now? In this example, Joe burned only 96 calories on his walk, but he burned 194 calories during his jog. Not only that, but Joe burned 90 fat calories on his jog versus only 64 fat calories on his walk.
~Lori Dotson, CPT, CPFT, PES, BA, MS
President, DotsoFit, LLC
Copyright © 2013
Okay, first let's remove that big white elephant from the room: There's no such thing as a fat-burning zone. There, said it.
I'll explain in a minute why this is a myth, but first let me say that exercising in this zone, which is typically defined as 65-75% of maximum heart rate (MHR) should definitely be a part of your training repertoire. And when I say training, I am still referring to you folks out there who may not be training for athletic competition, but just want to look and feel good. The 65-75% MHR training zone is necessary to build an aerobic base and to aid in recovery. You can't go hard day after day, not only will you burn out quickly, but you will make yourself more vulnerable to injury and respiratory infections. All people, whether they're elite athletes or your average Joe (or Jane) need to practice the PROS (progression, regularity, overload, and specificity), something that I discuss in my book, DotsoFit Health and Fitness, available at Amazon.com.
Below is the table that everyone came to this website to see. Now, skip to the bottom of this post if you want to see why the fat-burning zone is a myth.
Percentage of Calories from Fats and Carbohydrates at Different Exercise Intensities (neglecting protein contribution to energy)
| RER1 | Approximate HR2 Training Zone | % Calories Burned from Carbohydrates | % Calories Burned from Fats |
| 0.71 | RHR3 | 0.0 | 100.0 |
| 0.75 | <65% MHR4 | 15.6 | 84.4 |
| 0.80 | 65% MHR | 33.4 | 66.6 |
| 0.85 | 70% MHR | 50.7 | 49.3 |
| 0.90 | 75% MHR | 67.5 | 32.5 |
| 0.95 | 75-80% MHR | 84.0 | 16.0 |
| 1.00 | 80-85% MHR (anaerobic threshold) | 100.0 | 0.0 |
| 1.10 | 90% MHR | 100.0 | 0.0 |
| 1.30 | MHR | 100.0 | 0.0 |
2HR = heart rate, 3RHR = resting HR, 4MHR = maximum HR
If Joe had doubled his speed to 6 mph for 20 minutes (this is a slow jog, a 10-minute-mile pace), Joe would have burned 46% of his calories from fat and 54% from carbohydrates. However, because Joe is working harder, he is burning more total calories, and the actual numbers come out to be about 90 calories from fat and 104 calories from carbohydrates.
Do you get it now? In this example, Joe burned only 96 calories on his walk, but he burned 194 calories during his jog. Not only that, but Joe burned 90 fat calories on his jog versus only 64 fat calories on his walk.
~Lori Dotson, CPT, CPFT, PES, BA, MS
President, DotsoFit, LLC
Copyright © 2013
