LOWER HEART RATE BURN MORE FAT

cjack19

bumping for reading later :0) great topic, I wondered this myself and hadn't gotten around to researching it!

mrsredneckmorris

Thanks for asking this question! It taught me something I didn't know!

I found this article that explains why it's better to work out with a lower heartrate. Apparently, once you burn through your sugar stores, your body starts burning other energy sources (either muscle or fat). It takes longer to break down fat than muscle, so it's better to require less energy (lower heart rate) so that your body can focus on the fat and leave the muscle alone.

http://www.livestrong.com/article/351353-why-do-you-burn-more-fat-at-lower-heart-rate/

So i went to the website and it breaks it down on why you need a lower heart right. Think this paragraph explains it the best


Heart Rate and Fat Burning
Once you have depleted your sugar stores, your body has to break down other tissues, such as fat, for energy. Breaking down fat is not instantaneous; the body needs time and energy to convert fatty acids into a usable fuel. If your rate of exercise is faster than the rate at which you can break down fat, your body will focus tissues that are easier to break down, such as muscle tissue. Working out at a lower intensity, therefore a lower heart rate, gives the body time to break down fats for fuel. This is why you burn more fat at a lower heart rate.

There are a couple of problems with this "explanation". First of all, it uses the phrase "once you have depleted your sugar stores" as though this is some common occurrence.

It isn't. Your body has enough glycogen stored for about 1-2 hours of continuous aerobic exercise. The average person rarely "depletes" their "sugar stores" in one workout. When marathoners do this, it's called "hitting the wall"--not a pleasant way to exercise.

Two: "depleting your sugar stores" is likely to cause your body to start breaking down muscle mass to scavenge the carbon skeleton.

Three: regardless of all of these processes, what happens during an individual workout--how much fat you do or don't burn, how much "muscle" you do or don't "burn"--has little to no effect in the long-term. Once you workout ends, the body has 22-23 hours to "put everything back" so to speak, and, as part of that process, shifts fat burning in response to what you did during exercise. Evidence has clearly shown that 24 hour fat oxidation is NOT affected by the amount of fat burned during an exercise workout.

Four: Even if the "fat burning" hypothesis WERE true, the difference in actual fat burned between a "fat burning" and "sugar burning" workout is negligible.

Five: numerous studies over last 5 years have shown that higher-intensity training results in greater body fat loss than low-level cardiovascular exercise (although that doesn't mean people should do only high intensity exercise).

Six: Even if some of the "fat burning" stuff is true, one must then deal with the significant variability of heart rate response to exercise. Unless you have done a scientific, symptom-limited, maximal graded exercise test, there is no way a "trainer" during an initial session can give you an accurate "fat burning" heart rate. If you/the trainer are using age-predicted target heart rate calculations, or HRM calculated "zones", or charts on machines, you could easily be off by 10-30 beats/minute.

Bottom line: the "heart rate burns more fat" concept was debunked 20 years ago. You have to seriously, and I mean seriously, question the qualifications of ANY "trainer" or health professional that would still promote this concept.

For optimal results for fitness, health, and weight loss, I recommend following a balanced program--one that includes endurance cardio, tempo cardio, higher-intensity interval cardio, and resistance training.

Wow, I need to research this further.
Adzak, in your opinion would this mean that I (or anyone) really doesn't need to get a heart rate monitor to train within zones to either burn fat or build endurance? I was under the impression that it was good to train in zones.

Azdak

Thanks for asking this question! It taught me something I didn't know!

I found this article that explains why it's better to work out with a lower heartrate. Apparently, once you burn through your sugar stores, your body starts burning other energy sources (either muscle or fat). It takes longer to break down fat than muscle, so it's better to require less energy (lower heart rate) so that your body can focus on the fat and leave the muscle alone.

http://www.livestrong.com/article/351353-why-do-you-burn-more-fat-at-lower-heart-rate/

So i went to the website and it breaks it down on why you need a lower heart right. Think this paragraph explains it the best


Heart Rate and Fat Burning
Once you have depleted your sugar stores, your body has to break down other tissues, such as fat, for energy. Breaking down fat is not instantaneous; the body needs time and energy to convert fatty acids into a usable fuel. If your rate of exercise is faster than the rate at which you can break down fat, your body will focus tissues that are easier to break down, such as muscle tissue. Working out at a lower intensity, therefore a lower heart rate, gives the body time to break down fats for fuel. This is why you burn more fat at a lower heart rate.

There are a couple of problems with this "explanation". First of all, it uses the phrase "once you have depleted your sugar stores" as though this is some common occurrence.

It isn't. Your body has enough glycogen stored for about 1-2 hours of continuous aerobic exercise. The average person rarely "depletes" their "sugar stores" in one workout. When marathoners do this, it's called "hitting the wall"--not a pleasant way to exercise.

Two: "depleting your sugar stores" is likely to cause your body to start breaking down muscle mass to scavenge the carbon skeleton.

Three: regardless of all of these processes, what happens during an individual workout--how much fat you do or don't burn, how much "muscle" you do or don't "burn"--has little to no effect in the long-term. Once you workout ends, the body has 22-23 hours to "put everything back" so to speak, and, as part of that process, shifts fat burning in response to what you did during exercise. Evidence has clearly shown that 24 hour fat oxidation is NOT affected by the amount of fat burned during an exercise workout.

Four: Even if the "fat burning" hypothesis WERE true, the difference in actual fat burned between a "fat burning" and "sugar burning" workout is negligible.

Five: numerous studies over last 5 years have shown that higher-intensity training results in greater body fat loss than low-level cardiovascular exercise (although that doesn't mean people should do only high intensity exercise).

Six: Even if some of the "fat burning" stuff is true, one must then deal with the significant variability of heart rate response to exercise. Unless you have done a scientific, symptom-limited, maximal graded exercise test, there is no way a "trainer" during an initial session can give you an accurate "fat burning" heart rate. If you/the trainer are using age-predicted target heart rate calculations, or HRM calculated "zones", or charts on machines, you could easily be off by 10-30 beats/minute.

Bottom line: the "heart rate burns more fat" concept was debunked 20 years ago. You have to seriously, and I mean seriously, question the qualifications of ANY "trainer" or health professional that would still promote this concept.

For optimal results for fitness, health, and weight loss, I recommend following a balanced program--one that includes endurance cardio, tempo cardio, higher-intensity interval cardio, and resistance training.

Wow, I need to research this further.
Adzak, in your opinion would this mean that I (or anyone) really doesn't need to get a heart rate monitor to train within zones to either burn fat or build endurance? I was under the impression that it was good to train in zones.

Training will always result in "fat burning". In general, I advise people to focus on the training aspect of a program first, since that will usually involve getting fit as well as losing weight, and because increasing fitness usually enhances weight loss.

For cardio exercise, there are basically three workout intensities: easy, medium, hard. Working at those intensities can be done either continuously or using interval training (generally, easy workouts are done continuously and hard workouts use mainly intervals--the medium intensity workouts will see more of a mixture). Some people try to divide cardio intensities into 5 or 6 "zones", but I think that is vast overkill and not practical for the average exerciser---heart rates are not that precise.

So once we decide to do easy, medium, and hard workouts, how should one track intensity? Some people find it useful to use HRMs, some do fine with perceived exertion. HRM data gives you something a little more "tangible", but perceived exertion can be more consistent over a longer workout (during longer workouts, heart rate can increase significantly, even when workload is unchanged--perceived exertion (mostly breathing) will stay more consistent). HRMs provide data that can be saved and reviewed and used to compare with other workouts.

Short answer: HRMs are great tools if you know how to use them, but I do not think they are absolutely necessary. I always wear a HRM and have for 15 years or more, but I am a data-intensive guy and I also know what the numbers mean. In addition, I ran for 10-15 years before HR monitoring was even available, so I was pretty dialed in to how I felt (perceived exertion) at different intensities.

The bottom line is to not get hung up on the "fat burning" aspect of exercise. The amount of actual fat burned during a long cardio workout is not that much, and the percentage of fat burned during a workout has no real effect on weight loss. Exercise training enhances a weight loss program primarily through contributing to a long-term caloric deficit (because cardio exercise burns a lot of calories) and by conserving lean mass.

Diet has more direct effect on weight/fat loss than exercise.

Exercise training is enhanced by varying your workout intensities and durations. Increasing fitness leads to greater caloric burn which promotes increased weight loss.

Hope this makes sense.

jtbaddison

I did a lot of research on this, and Azdak is correct. HR Zones have been totally debunked. Ever see Biggest Loser trainers trying to keep heart rates down? Most of recent exercise science points to a positive correlation between intensity and body fat loss. Its easy to find articles that go either way, but its hard to find studies that support an antiquated viewpoint.

mrsredneckmorris

Thanks for the detail, and yes it makes complete sense to me!

CulturedCowgurl

Thanks for asking this question! It taught me something I didn't know!

I found this article that explains why it's better to work out with a lower heartrate. Apparently, once you burn through your sugar stores, your body starts burning other energy sources (either muscle or fat). It takes longer to break down fat than muscle, so it's better to require less energy (lower heart rate) so that your body can focus on the fat and leave the muscle alone.

http://www.livestrong.com/article/351353-why-do-you-burn-more-fat-at-lower-heart-rate/

So i went to the website and it breaks it down on why you need a lower heart right. Think this paragraph explains it the best


Heart Rate and Fat Burning
Once you have depleted your sugar stores, your body has to break down other tissues, such as fat, for energy. Breaking down fat is not instantaneous; the body needs time and energy to convert fatty acids into a usable fuel. If your rate of exercise is faster than the rate at which you can break down fat, your body will focus tissues that are easier to break down, such as muscle tissue. Working out at a lower intensity, therefore a lower heart rate, gives the body time to break down fats for fuel. This is why you burn more fat at a lower heart rate.

There are a couple of problems with this "explanation". First of all, it uses the phrase "once you have depleted your sugar stores" as though this is some common occurrence.

It isn't. Your body has enough glycogen stored for about 1-2 hours of continuous aerobic exercise. The average person rarely "depletes" their "sugar stores" in one workout. When marathoners do this, it's called "hitting the wall"--not a pleasant way to exercise.

Two: "depleting your sugar stores" is likely to cause your body to start breaking down muscle mass to scavenge the carbon skeleton.

Three: regardless of all of these processes, what happens during an individual workout--how much fat you do or don't burn, how much "muscle" you do or don't "burn"--has little to no effect in the long-term. Once you workout ends, the body has 22-23 hours to "put everything back" so to speak, and, as part of that process, shifts fat burning in response to what you did during exercise. Evidence has clearly shown that 24 hour fat oxidation is NOT affected by the amount of fat burned during an exercise workout.

Four: Even if the "fat burning" hypothesis WERE true, the difference in actual fat burned between a "fat burning" and "sugar burning" workout is negligible.

Five: numerous studies over last 5 years have shown that higher-intensity training results in greater body fat loss than low-level cardiovascular exercise (although that doesn't mean people should do only high intensity exercise).

Six: Even if some of the "fat burning" stuff is true, one must then deal with the significant variability of heart rate response to exercise. Unless you have done a scientific, symptom-limited, maximal graded exercise test, there is no way a "trainer" during an initial session can give you an accurate "fat burning" heart rate. If you/the trainer are using age-predicted target heart rate calculations, or HRM calculated "zones", or charts on machines, you could easily be off by 10-30 beats/minute.

Bottom line: the "heart rate burns more fat" concept was debunked 20 years ago. You have to seriously, and I mean seriously, question the qualifications of ANY "trainer" or health professional that would still promote this concept.

For optimal results for fitness, health, and weight loss, I recommend following a balanced program--one that includes endurance cardio, tempo cardio, higher-intensity interval cardio, and resistance training.

Wow, I need to research this further.
Adzak, in your opinion would this mean that I (or anyone) really doesn't need to get a heart rate monitor to train within zones to either burn fat or build endurance? I was under the impression that it was good to train in zones.

Training will always result in "fat burning". In general, I advise people to focus on the training aspect of a program first, since that will usually involve getting fit as well as losing weight, and because increasing fitness usually enhances weight loss.

For cardio exercise, there are basically three workout intensities: easy, medium, hard. Working at those intensities can be done either continuously or using interval training (generally, easy workouts are done continuously and hard workouts use mainly intervals--the medium intensity workouts will see more of a mixture). Some people try to divide cardio intensities into 5 or 6 "zones", but I think that is vast overkill and not practical for the average exerciser---heart rates are not that precise.

So once we decide to do easy, medium, and hard workouts, how should one track intensity? Some people find it useful to use HRMs, some do fine with perceived exertion. HRM data gives you something a little more "tangible", but perceived exertion can be more consistent over a longer workout (during longer workouts, heart rate can increase significantly, even when workload is unchanged--perceived exertion (mostly breathing) will stay more consistent). HRMs provide data that can be saved and reviewed and used to compare with other workouts.

Short answer: HRMs are great tools if you know how to use them, but I do not think they are absolutely necessary. I always wear a HRM and have for 15 years or more, but I am a data-intensive guy and I also know what the numbers mean. In addition, I ran for 10-15 years before HR monitoring was even available, so I was pretty dialed in to how I felt (perceived exertion) at different intensities.

The bottom line is to not get hung up on the "fat burning" aspect of exercise. The amount of actual fat burned during a long cardio workout is not that much, and the percentage of fat burned during a workout has no real effect on weight loss. Exercise training enhances a weight loss program primarily through contributing to a long-term caloric deficit (because cardio exercise burns a lot of calories) and by conserving lean mass.

Diet has more direct effect on weight/fat loss than exercise.

Exercise training is enhanced by varying your workout intensities and durations. Increasing fitness leads to greater caloric burn which promotes increased weight loss.

Hope this makes sense.

I know this is an old posts but it is still very informative. Thank You.

ninerbuff

So i just joined the gym and yesterday the trainer had me walk on the treadmill with an incline of 8.5 (the highest i've ever done go me) but he didn't want my heart rate to go higher than 140. I am 26 years old and 218lb just an FYI. I've always thought i was suppose to workout at the higher heart rate to burn more. I had to drop my speed all the way to 1.6 to even get my heart rate to 145 and that's the lowest it went. I stayed at 160 until i dropped the speed that low. Felt a little strange walking that slow but my legs are burning this morning probably due to the incline. Any thoughts on why i needed to stay at the lower heart rate? I do another assessment today so he probably will explain more, but i'm curious.

While it's true that the body uses more fat as an energy source when intensity is much lower, to match the calorie burn for a higher intensity exercise would entail a much longer duration. For some up to 2 hours more. So if you're willing to go that long vs doing 30 minutes of higher intensity to burn the same amount, then more power to you.
It may be that the trainer was testing to see what your threshhold of endurance and conditioning were.

A.C.E. Certified Personal/Group FitnessTrainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

ninerbuff

Thanks for asking this question! It taught me something I didn't know!

I found this article that explains why it's better to work out with a lower heartrate. Apparently, once you burn through your sugar stores, your body starts burning other energy sources (either muscle or fat). It takes longer to break down fat than muscle, so it's better to require less energy (lower heart rate) so that your body can focus on the fat and leave the muscle alone.

http://www.livestrong.com/article/351353-why-do-you-burn-more-fat-at-lower-heart-rate/

You'd have to do quite of bit of low intensity work before burning through glycogen though. That could end up being a 5 hour walk to even start tapping fat stores.

A.C.E. Certified Personal/Group FitnessTrainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition