LOWER HEART RATE BURN MORE FAT

lhinds85
lhinds85 Posts: 65 Member
edited October 2024 in Fitness and Exercise
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.

Replies

  • leomom72
    leomom72 Posts: 1,797 Member
    that sounds weird..im kinda curious now..good luck:drinker:
  • cmon288
    cmon288 Posts: 173 Member
    When you find out please share!
  • Gunff
    Gunff Posts: 47
    140 is still well in the normal range for cardio at 26 years old. My guess is that he wanted lower heart rate (Slower) so that you could go longer without getting tired.
  • russellma
    russellma Posts: 284 Member
    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/
  • vicki915
    vicki915 Posts: 38 Member
    No idea, but I am curios too. I also thought that the higher heart rate burned the fat. So I'll be checking back to see his explanation.
  • ricochette55
    ricochette55 Posts: 68 Member
    I've been wondering the same thing...I got an HRM recently and my heart rate gets pretty high during cardio and the HRM tells me I only spend about 5 minutes in the 'fat burn zone' and most time in the 'fitness zone'. I've been curious how important that is for weight loss. I think a calorie burned is a calorie burned, no matter what zone I'm in, but...???
  • marycmeadows
    marycmeadows Posts: 1,691 Member
    the lower heart rate is fat burn - it burns the fat you have stored after burning off the energy you have put in your body that day..... higher speeds/higher heart rate builds endurance too - it is better to go slower for longer sometimes.
  • lhinds85
    lhinds85 Posts: 65 Member
    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.
  • Azdak
    Azdak Posts: 8,281 Member
    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.
  • Azdak
    Azdak Posts: 8,281 Member
    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/

    That article uses just enough facts to be completely wrong.
  • russellma
    russellma Posts: 284 Member
    LOL. Maybe I didn't learn so much after all, huh? :blushing:

    Now that you've made me dig, I think I do have a better grasp on the fat-burning thing. Thanks!

    This link was helpful on the the fat-burning zone question, and maybe will be helpful to anyone else who's curious:

    http://www.sharecare.com/question/fat-burning-zone-really-myth

    However, I'm not sure that it's fair to assume that because that's the answer Google gave to me at first glance, that that's the reason that the trainer has. Let's give him the benefit of the doubt and she can ask him herself the next time she sees him. :ohwell:
  • lhinds85
    lhinds85 Posts: 65 Member
    so here is his verdict on why i should stay at a lower heart rate. Pretty much what we thought. We start to burn muscle after a certain period of time when we work out. First you burn sugar, then fat, then muscle. If you're heart rate is over the fat burning range you will use all the fat you have to burn quickly and then the body goes into using other sources "muscle". Some might disagree but to each its on. Its different, but if you keep doing th same thing you've always done you can't expect anything different. So i'm going to try this out and some of his other techniques for awhile. He made sense to me.
  • bcattoes
    bcattoes Posts: 17,299 Member
    I've heard this on these boards but 50 years of experience hasn't proved it true for me.
  • AlsDonkBoxSquat
    AlsDonkBoxSquat Posts: 6,128 Member
    so here is his verdict on why i should stay at a lower heart rate. Pretty much what we thought. We start to burn muscle after a certain period of time when we work out. First you burn sugar, then fat, then muscle. If you're heart rate is over the fat burning range you will use all the fat you have to burn quickly and then the body goes into using other sources "muscle". Some might disagree but to each its on. Its different, but if you keep doing th same thing you've always done you can't expect anything different. So i'm going to try this out and some of his other techniques for awhile. He made sense to me.

    Just please remember that a car that's been in a flood doesn't mean that it's "throughly cleaned" no matter how good the sales pitch. You are paying this guy to use antequated techniques to train you. If you've been doing nothing for a period of time except sit on the couch and eat fried food and all of a sudden are do some sort of movement and eating better you are going to get results, but maybe not the best results.
  • JamesBurkes
    JamesBurkes Posts: 382 Member
    Yes, looks like he's a believer in the "fat burning zone" - 140 would be around 70% of your max heart rate, which places it right there.

    There's certainly some benefit to doing this kind of workout (if you're new to exercise or if you're too tired to do something more intense and want "active recovery" that'll also burn some fat).

    But Azdak is right - there's no real benefits to working out in that zone over more intense cardio, apart from those I've already mentioned.

    Then again, I take most exercise studies with a pinch of salt and generally just go from experience. Sometimes you can know too much about fuel sources, hormone release, fat-burning enzymes etc. I follow a low-carb diet and do HIIT cardio and high intensity cardio (spinning etc). According to the science this should be a bad thing as the limited carbs in my system means I'm burning off mostly muscle.

    All I know however, is that my waist measurement is dropping (fast!), my chest, arm and thigh measurements are static (or increasing) and the weights I lift are increasing, too. As long as this stays the case, I'll carry on doing what I'm doing, and will just ignore the consensus.
  • lhinds85
    lhinds85 Posts: 65 Member
    I could not afford to pay him to be my trainer. I thought he made some valid points. I agree with you about me doing any type of exercise will show results since i haven't been working out in quite some time. I do feel that i need to add more muscle to my body and lose weight. Bottom line i will be hitting the gym hard and i know i will have to change up my routine or i will hit a wall.
  • Azdak
    Azdak Posts: 8,281 Member
    Yes, looks like he's a believer in the "fat burning zone" - 140 would be around 70% of your max heart rate, which places it right there.

    There's certainly some benefit to doing this kind of workout (if you're new to exercise or if you're too tired to do something more intense and want "active recovery" that'll also burn some fat).

    But Azdak is right - there's no real benefits to working out in that zone over more intense cardio, apart from those I've already mentioned.

    Then again, I take most exercise studies with a pinch of salt and generally just go from experience. Sometimes you can know too much about fuel sources, hormone release, fat-burning enzymes etc. I follow a low-carb diet and do HIIT cardio and high intensity cardio (spinning etc). According to the science this should be a bad thing as the limited carbs in my system means I'm burning off mostly muscle.

    All I know however, is that my waist measurement is dropping (fast!), my chest, arm and thigh measurements are static (or increasing) and the weights I lift are increasing, too. As long as this stays the case, I'll carry on doing what I'm doing, and will just ignore the consensus.

    Don't know what "science" you are reading, but there is little to support the idea that you are "burning muscle". The problem is not usually with the quality of the "exercise studies"--it's more with the interpretation of those results.
  • crux
    crux Posts: 454 Member

    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.

    It's hard to argue with this advice. I would only add that the cardio is best spread between a few different activities too if you can.

    We all get hung up on burning fat. But eating right and doing a range of physically and mentally invigorating exercise is surely one of the keys to that all important 'lifestyle change'.... Which leads to the fat loss in a sustainable & maintainable way.
  • ATT949
    ATT949 Posts: 1,245 Member
    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/

    The only way to burn muscle is on a grill…

    Seriously. If I read an article that talked about "burning muscle", I'd skip to another article.

    I've seen discussion about the "fat burning zone" vs "what counts is how many calories you burn" for a long time (decades). Polar makes an HRM to support that approach. In addition, one of the books that I've read talks about running at a low enough HR so that you will burn fat instead of glycogen.

    When I was losing weight I tried the "fat burning rate" on an elliptical for about 3 minutes and, pardon the pun, I couldn't stand it. The rate was way too low to get me interested in that exercise and at that HR I wasn't increasing my cardio.

    Losing weight faster was never an issue for me because I cut my calorie intake to 800 to 1000 net/day.
  • ATT949
    ATT949 Posts: 1,245 Member
    so here is his verdict on why i should stay at a lower heart rate. Pretty much what we thought. We start to burn muscle after a certain period of time when we work out. First you burn sugar, then fat, then muscle. If you're heart rate is over the fat burning range you will use all the fat you have to burn quickly and then the body goes into using other sources "muscle". Some might disagree but to each its on. Its different, but if you keep doing th same thing you've always done you can't expect anything different. So i'm going to try this out and some of his other techniques for awhile. He made sense to me.
    My layman's understanding (which I would love to see confirmed or corrected by someone who is educated on this topic).

    Your muscles cannot burn fat or muscle. Muscles burn, among other things, glucose.

    To the best of my understanding, at low heart rates, you burn fat. "low" is in the 50% of max HR, IIRC, and at that heart rate, fat is converted to glycogen which is then converted to glucose.

    Once you move up in the HR zones, you start consuming glycogen instead of fat. Glycogen is stored in the muscles and the liver and is converted to glucose at higher activity levels.

    I could never get into exercising at a low HR. It was tedious and time consuming. In addition, it did nothing for my cardiovascular system. Even now that I run, I have a very hard time doing long slow distance at much below 80% of max HR.

    Insofar as losing weight - I didn't use exercise as the primary means of calorie deficit. To me, exercise was the icing on the cake. Instead, I went with a low calorie diet (800 to 1k net cals for about 6 days a week and never over 1500 net) and lost 95 pounds in 7 months. I figured it was easier to not put it in my mouth than to try to sweat it off. If appears to have worked. :-)
  • cjack19
    cjack19 Posts: 158 Member
    bumping for reading later :0) great topic, I wondered this myself and hadn't gotten around to researching it!
  • mrsredneckmorris
    mrsredneckmorris Posts: 119 Member
    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
    Azdak Posts: 8,281 Member
    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
    jtbaddison Posts: 134 Member
    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
    mrsredneckmorris Posts: 119 Member
    Thanks for the detail, and yes it makes complete sense to me!
  • CulturedCowgurl
    CulturedCowgurl Posts: 136 Member
    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
    ninerbuff Posts: 49,082 Member
    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
    ninerbuff Posts: 49,082 Member
    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
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