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Fat Burning Zone

smit7633
smit7633 Posts: 182 Member
Fact or Crap?
«1

Replies

  • yarwell
    yarwell Posts: 10,477 Member
    The % of energy you get from fat vs carbohydrate changes with the intensity of the exercise :-

    F2.medium.gif


    and the amount of fat oxidised goes through a maximum :-

    1lzr5uwb9w0c.png
  • stevencloser
    stevencloser Posts: 8,911 Member
    edited April 2016
    The way our body works, it will always use a mix of fat and glycogen for fuel. The more you exert yourself, the higher the percentage of glycogen, because it's easy to access and just a faster process altogether. So basically, you're burning the most fat percentage wise while you're sleeping, when glycogen is only used to keep your blood sugar steady.
    However, of course, during exercise you'll burn more total calories, so there is some point at which, even though you'll burn less fat percentually, the amount of calories from fat you burn peak. That point is somewhere along 60% of your max intensity.

    http://sportsscientists.com/2010/01/exercise-and-weight-loss-part-3-fat/

    Again however, and they talk about it, it doesn't make you lose fat any faster in the long term, that's still bound by CICO. But they don't say why in that article I think.

    The why is easy. Even if you train up to an intensity where you're almost exclusively using glycogen for fuel, later on during your next meal(s) that glycogen will be replenished by carbs from your meal(s) because the body tries to keep glycogen levels up for intense exercise like the one you just did and for your blood sugar levels.
    http://www.ncbi.nlm.nih.gov/books/NBK21190/

    Those carbs that are used to replenish your glycogen are then obviously not available for fuel, your current deficit is increased from that and you're losing fat because you're at rest. So while you didn't burn much fat during exercise, you're burning extra afterwards. It's like you delayed the fat loss from during the exercise to the rest time afterwards.


    Maybe an example helps illustrate that.

    Let's say your normal daily burn is 2000, your exercise burned 500 at 100% glycogen use.
    That means your glycogen stores are down by 500 calories, you lost no fat so far.
    You're eating 2000 calories that day, you're at -500 calories but all of those were from glycogen, oh noes!
    But, 500 of those 2000 calories you ate go to replenishing your glycogen stores, it's "paying" for your exercise so to speak, and the other 1500 go to your normal burns and you end up at -500 calories that are going to be taken from mostly fat.

    That's simplified of course.


    Tl;dr: It's another biological fact that gets widely misrepresented by the diet industry.
  • kommodevaran
    kommodevaran Posts: 17,890 Member
    Majoring in the minors :D
  • Scamd83
    Scamd83 Posts: 808 Member
    Can I come in the fat burning zone please?
  • RWClary
    RWClary Posts: 192 Member
    smit7633 wrote: »
    Fact or Crap?
    My experience has been that long aerobic sessions have that "fat burning zone", but once you stop the activity, then what?
    I once heard a bodybuilding guy call it the "Muscle Burning Zone"...lol
    So, aerobic training is fine, and added strength training and HIIT have effects on fat burning while a body is at rest.

    Maybe some science folk will further elaborate. I am not wired for science, but I got an "A" in PE...and today the guy who got an "A" in science pays me to wash his car...but I digress....


  • smit7633
    smit7633 Posts: 182 Member
    Cool!
  • ForecasterJason
    ForecasterJason Posts: 2,577 Member
    I found out unintentionally from personal experience the truth that low intensity exercise does indeed burn more fat than carbs.
  • Azdak
    Azdak Posts: 8,281 Member
    edited April 2016
    Fuel substrate used during exercise has no effect on loss of body fat. Exercising in "fat burning zone" enhances ability to utilize more fat during exercise which can possibly improve endurance performance, but does not lead to greater loss of fat. Body uses/stores fat on a 24hr/365 day basis--exercise only a tiny part of that. Depending on how much used during exercise, body will up or down regulate fat oxidation the rest of the day. Still depends on calorie deficit.

    Conclusion: crap
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    The way our body works, it will always use a mix of fat and glycogen for fuel. The more you exert yourself, the higher the percentage of glycogen, because it's easy to access and just a faster process altogether. So basically, you're burning the most fat percentage wise while you're sleeping, when glycogen is only used to keep your blood sugar steady.
    However, of course, during exercise you'll burn more total calories, so there is some point at which, even though you'll burn less fat percentually, the amount of calories from fat you burn peak. That point is somewhere along 60% of your max intensity.

    http://sportsscientists.com/2010/01/exercise-and-weight-loss-part-3-fat/

    Again however, and they talk about it, it doesn't make you lose fat any faster in the long term, that's still bound by CICO. But they don't say why in that article I think.

    The why is easy. Even if you train up to an intensity where you're almost exclusively using glycogen for fuel, later on during your next meal(s) that glycogen will be replenished by carbs from your meal(s) because the body tries to keep glycogen levels up for intense exercise like the one you just did and for your blood sugar levels.
    http://www.ncbi.nlm.nih.gov/books/NBK21190/

    Those carbs that are used to replenish your glycogen are then obviously not available for fuel, your current deficit is increased from that and you're losing fat because you're at rest. So while you didn't burn much fat during exercise, you're burning extra afterwards. It's like you delayed the fat loss from during the exercise to the rest time afterwards.


    Maybe an example helps illustrate that.

    Let's say your normal daily burn is 2000, your exercise burned 500 at 100% glycogen use.
    That means your glycogen stores are down by 500 calories, you lost no fat so far.
    You're eating 2000 calories that day, you're at -500 calories but all of those were from glycogen, oh noes!
    But, 500 of those 2000 calories you ate go to replenishing your glycogen stores, it's "paying" for your exercise so to speak, and the other 1500 go to your normal burns and you end up at -500 calories that are going to be taken from mostly fat.

    That's simplified of course.


    Tl;dr: It's another biological fact that gets widely misrepresented by the diet industry.

    Really good post. Everyone should read it.
  • yarwell
    yarwell Posts: 10,477 Member
    edited April 2016
    Azdak wrote: »
    Fuel substrate used during exercise has no effect on loss of body fat.

    Do you have any evidence for that ?

    Saw this earlier, which sounded relevant : smile:

    "For over 20 years, we at [redacted] have seen this all too often, particularly with women. Many of these ladies are on a vigorous aerobic exercise routine (spinning classes, running, cycling or swimming) and they are VERY committed to their program. Yet when they finish their daily exercise they more than likely eat a lot of carbohydrates and they even may be told by a trainer to eat a lot of “good carbs” to keep their glycogen charged which will ensure a great workout. To continue to do this and expect to have great weight loss success is folly as we are just replenishing the glycogen that we burnt during exercise. "

    Sounds like the back half of many marathons and fun runs.
  • stevencloser
    stevencloser Posts: 8,911 Member
    yarwell wrote: »
    Azdak wrote: »
    Fuel substrate used during exercise has no effect on loss of body fat.

    Do you have any evidence for that ?

    Saw this earlier, which sounded relevant : smile:

    "For over 20 years, we at [redacted] have seen this all too often, particularly with women. Many of these ladies are on a vigorous aerobic exercise routine (spinning classes, running, cycling or swimming) and they are VERY committed to their program. Yet when they finish their daily exercise they more than likely eat a lot of carbohydrates and they even may be told by a trainer to eat a lot of “good carbs” to keep their glycogen charged which will ensure a great workout. To continue to do this and expect to have great weight loss success is folly as we are just replenishing the glycogen that we burnt during exercise. "

    Sounds like the back half of many marathons and fun runs.

    And if you stay at a deficit, the glycogen repletion means you have less calories for your normal day to day burn that will be fueled by fat.

    Deficit, like always.
  • Scamd83
    Scamd83 Posts: 808 Member
    edited April 2016
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.
  • Azdak
    Azdak Posts: 8,281 Member
    yarwell wrote: »
    Azdak wrote: »
    Fuel substrate used during exercise has no effect on loss of body fat.

    Do you have any evidence for that ?

    Saw this earlier, which sounded relevant : smile:

    "For over 20 years, we at [redacted] have seen this all too often, particularly with women. Many of these ladies are on a vigorous aerobic exercise routine (spinning classes, running, cycling or swimming) and they are VERY committed to their program. Yet when they finish their daily exercise they more than likely eat a lot of carbohydrates and they even may be told by a trainer to eat a lot of “good carbs” to keep their glycogen charged which will ensure a great workout. To continue to do this and expect to have great weight loss success is folly as we are just replenishing the glycogen that we burnt during exercise. "

    Sounds like the back half of many marathons and fun runs.

    No I just made it up for fun.

    Of course I do:

    Look up Melanson et al. Exercise improves fat metabolism in muscle but does not
    increase 24-h fat oxidation

    Title pretty much says it all.


  • Azdak
    Azdak Posts: 8,281 Member
    Scamd83 wrote: »
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.

    Basically, yes. The overall goal of exercise should be to improve fitness level. The higher your fitness, the more work you can do at any intensity level, and thus the more calories you will burn.

    For most people, this will be best achieved with a mix of endurance, tempo, and high intensity interval training.
  • smit7633
    smit7633 Posts: 182 Member
    So I thought the point if exercise was to help create that calorie deficit and to hopefully not loose too much muscle when you're eating less...please advise
    Azdak wrote: »
    Fuel substrate used during exercise has no effect on loss of body fat. Exercising in "fat burning zone" enhances ability to utilize more fat during exercise which can possibly improve endurance performance, but does not lead to greater loss of fat. Body uses/stores fat on a 24hr/365 day basis--exercise only a tiny part of that. Depending on how much used during exercise, body will up or down regulate fat oxidation the rest of the day. Still depends on calorie deficit.

    Conclusion: crap

  • smit7633
    smit7633 Posts: 182 Member
    Azdak wrote: »
    Scamd83 wrote: »
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.

    Basically, yes. The overall goal of exercise should be to improve fitness level. The higher your fitness, the more work you can do at any intensity level, and thus the more calories you will burn.

    For most people, this will be best achieved with a mix of endurance, tempo, and high intensity interval training.

    I have noticed that of the 20 lbs of weight I've lost so far less than half were fat pounds, I'm worried that my body is using my muscle instead of my fat to replace the food I'm eating less of.
  • ninerbuff
    ninerbuff Posts: 48,454 Member
    Crap. What most people don't realize that any physical activity that depletes glycogen and fat, will get restored from the consumption of nutrients and food that day.
    The "fat burning zone" IMO though true based on higher fat percentage of fat burned during low intensity exercise, was CREATED to help overweight people who didn't like exercise, do a form of exercise using their gym membership. Chalk that up to the fitness industry.

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

    9285851.png
  • RWClary
    RWClary Posts: 192 Member
    Scamd83 wrote: »
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.
    Yes, but you lose weight - not just "fat".
    And the exercises you engage will determine fitness levels and affect health.
    For mere weight loss, do whatever...eat whatever but maintain a calorie deficit.
    I always desired so much more than mere weight loss B)
  • Azdak
    Azdak Posts: 8,281 Member
    edited April 2016
    smit7633 wrote: »
    Azdak wrote: »
    Scamd83 wrote: »
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.

    Basically, yes. The overall goal of exercise should be to improve fitness level. The higher your fitness, the more work you can do at any intensity level, and thus the more calories you will burn.

    For most people, this will be best achieved with a mix of endurance, tempo, and high intensity interval training.

    I have noticed that of the 20 lbs of weight I've lost so far less than half were fat pounds, I'm worried that my body is using my muscle instead of my fat to replace the food I'm eating less of.

    And you are determining that how? Other than some specific health/medical conditions the max I've seen is around 35% of loss from Lean body mass-- and that's from people doing HCG and 500 cal/day diet.

    A recent client has lost 28 pounds since Jan 3rd. He cannot strength train, so it's all cardio and diet. Last check 24lbs was fat, 2lbs muscle, 2lbs water.
  • smit7633
    smit7633 Posts: 182 Member
    OK thanks
    Azdak wrote: »
    smit7633 wrote: »
    Azdak wrote: »
    Scamd83 wrote: »
    So basically the take home message from all of this is eat at a deficit, do whatever exercise you want at whatever intensity you want, lose fat.

    Basically, yes. The overall goal of exercise should be to improve fitness level. The higher your fitness, the more work you can do at any intensity level, and thus the more calories you will burn.

    For most people, this will be best achieved with a mix of endurance, tempo, and high intensity interval training.

    I have noticed that of the 20 lbs of weight I've lost so far less than half were fat pounds, I'm worried that my body is using my muscle instead of my fat to replace the food I'm eating less of.

    And you are determining that how? Other than some specific health/medical conditions the max I've seen is around 35% of loss from Lean body mass-- and that's from people doing HCG and 500 cal/day diet.

    A recent client has lost 28 pounds since Jan 3rd. He cannot strength train, so it's all cardio and diet. Last check 24lbs was fat, 2lbs muscle, 2lbs water.