Fat Burning Zone Confusion

MrsJennaKwasniewski
MrsJennaKwasniewski Posts: 204 Member
in Fitness and Exercise
I am trying to find out my fat burning zone and I have looked up information on finding it and have learned there are different “training zones” (fat burning, aerobic, steady state, anaerobic and maximal) based on your heart rate.

I have calculated my MHR (maximum heart rate) using the formula 220-(age) and my MHR is 191.

I then used the formula MHR x 0.55=lower level threshold fat burning zone and MHR x 0.70=upper level fat burning zone. My lower level is 105.05 and my upper level is 133.7

So from what I am understanding is that to be at my maximum fat burning potential I need to stay between 105.05-133.7 BPM. That is all understandable as far as the math is concerned.

The CONFUSING part is….
I do not have a heart rate monitor so I just check my heart rate several times while working out and then average the numbers later to get my average heart rate (which I am now learning that is wrong since my heart rate should be at a steady rate in the fat burning zone) Anyway that is what I was doing.

I am wondering why when I plug my numbers into http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx to calculate my calories burned, that when I have a heart rate of average 145 I burn more calories than an average of 125???

If http://www.livestrong.com/article/208307-how-to-calculate-heart-rate-for-fat-burn/ says “Once you have calculated your fat burning zone, be sure to adjust your intensity during exercise to stay within those upper and lower limits. Periodically check on your heart rate using one of the methods listed above. Your percentage of calories burned from fat will decrease if you go over this range.”

Then why does it show I burn MORE calories when I go out of the “fat burning zone” as opposed to when I stay in? I am so confused.

I do not want to lower the intensity or my workout just to stay in the zone if it is not going to actually burn more calories than at a higher heart rate. UGH Please help me out.

Replies

  • say_pocket
    say_pocket Posts: 54 Member
    Now I'm no expert, but if I understand correctly, the "fat burning zone" is only called that because as far as calorie burn goes, you are burning a higher percentage of stored fat calories than calories from the food you've eaten. But workouts with higher intensities (and therefore ones that raise your heart rate up higher) will burn more calories total.

    Here's an article that has pictures and may explain this better than I am: http://www.builtlean.com/2013/04/01/fat-burning-zone-myth/
  • levitateme
    levitateme Posts: 999 Member
    I am trying to find out my fat burning zone and I have looked up information on finding it and have learned there are different “training zones” (fat burning, aerobic, steady state, anaerobic and maximal) based on your heart rate.

    I have calculated my MHR (maximum heart rate) using the formula 220-(age) and my MHR is 191.

    I then used the formula MHR x 0.55=lower level threshold fat burning zone and MHR x 0.70=upper level fat burning zone. My lower level is 105.05 and my upper level is 133.7

    So from what I am understanding is that to be at my maximum fat burning potential I need to stay between 105.05-133.7 BPM. That is all understandable as far as the math is concerned.

    The CONFUSING part is….
    I do not have a heart rate monitor so I just check my heart rate several times while working out and then average the numbers later to get my average heart rate (which I am now learning that is wrong since my heart rate should be at a steady rate in the fat burning zone) Anyway that is what I was doing.

    I am wondering why when I plug my numbers into http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx to calculate my calories burned, that when I have a heart rate of average 145 I burn more calories than an average of 125???

    If http://www.livestrong.com/article/208307-how-to-calculate-heart-rate-for-fat-burn/ says “Once you have calculated your fat burning zone, be sure to adjust your intensity during exercise to stay within those upper and lower limits. Periodically check on your heart rate using one of the methods listed above. Your percentage of calories burned from fat will decrease if you go over this range.”

    Then why does it show I burn MORE calories when I go out of the “fat burning zone” as opposed to when I stay in? I am so confused.

    I do not want to lower the intensity or my workout just to stay in the zone if it is not going to actually burn more calories than at a higher heart rate. UGH Please help me out.

    "the fat burning zone" is kind of a myth. Well it's a myth that you must work in the fat burning zone (!!) .... The higher your heart rate goes, the more calories you are burning. You will burn a higher percentage of fat calories when you are in this supposed zone, and fat calories plus calories from glycogen/muscle loss when working at a higher heart rate. So it seems like a no brainer, just work in "the zone" and burn more fat... BUT your body burns more calories later on when you work at higher intensity. So what do you do?

    Personally, find out your TDEE -20%, eat that and don't add exercise calories. It's really not worth obsessing over. If you are moving and eating at a deficit, everything will fall into place.
  • Frood42
    Frood42 Posts: 245 Member
    Its a myth really, but this is a good article about cycle training that can be applied to other sports

    http://www.bikeradar.com/gear/article/heart-rate-monitor-training-for-cyclists-28838/

    Lower HR zones are good for building endurance and stamina.

    Both HIIT and really long steady state will both burn fat.
    .
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    Now I'm no expert, but if I understand correctly, the "fat burning zone" is only called that because as far as calorie burn goes, you are burning a higher percentage of stored fat calories than calories from the food you've eaten. But workouts with higher intensities (and therefore ones that raise your heart rate up higher) will burn more calories total.

    Here's an article that has pictures and may explain this better than I am: http://www.builtlean.com/2013/04/01/fat-burning-zone-myth/

    Exactly.

    The zones are based on the percentage of fuel by source. The fat burning zone uses fat for the preponderance of fuel but is a lower intensity and creates a lower overall caloric burn. Higher intensity aerobic activity burns more carbs than fat by percentage, but the total caloric burn is higher. Depending on duration and intensity, the amount of fat burned is often more when exercising above the so-called fat burning zone.
  • No_Finish_Line
    No_Finish_Line Posts: 3,661 Member
    question has been answered well.

    your cells need oxygen in order to burn fat (reffered to as cellular respiration). when your heart rate goes up, its your body attempting to more oxygen to your cells (and more quickly remove waste). Once your cells have a need to create energy faster then they are getting oxygen, your out of the 'fat burning' zone and you use another source of fuel.

    but since you can bet a way bigger defecit from going more intense, thats the better option. Also better for your health, working out in the lower intensity doesn't do as much good for your heart.

    its all about the defecit, one can lose weight simply by eating less then they burn from being awake... never exercising in the 'fat burning zone'... or at all
  • BrianSharpe
    BrianSharpe Posts: 9,248 Member
    The "fat burning zone" is a term that should be banished from the language (except in the context of endurance athletes who train their bodies to burn more fat than glycogen......but I digress).

    In the context of weight loss the previous posts are spot on.......exercising at a higher intensity burns more calories (it doesn't matter what the fuel source is) which has the potential to lead to a higher caloric deficit (or, in my case, lets me eat more food and maintain a reasonable deficit). The reason I used the term potential is that one of the paradoxes of exercise and weight loss is that you need to fuel the workouts (ie eat more) so that the exercise itself may contribute very little to weight loss but does offer a host of other health benefits.
  • MrsJennaKwasniewski
    MrsJennaKwasniewski Posts: 204 Member
    OK THANK YOU! I will just keep working out at a higher intensity and not worry about it. I already do eat at a deficit and do not eat back my workout calories so I am not REALLY stressed over it I was just confused. Thanks for all the great answers and the have answered my question perfectly!
  • ninerbuff
    ninerbuff Posts: 49,028 Member
    The "fat burning zone" while scientifically legit, ISN'T the most effective way to exercise. You burn more fat sleeping than you would going at a slow pace for an hour. And going slow won't help with raising your RMR. A higher RMR results in more fat burning at rest.
    Usually higher intensity work will result in an elevated RMR. Start there.

    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
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    The "fat burning zone" is essentially going for a walk...it is a low intensity activity that is going to primarily use stored fat as fuel...but due to the fact that it is not a very intense activity, it's really not going to burn that many calories. You are better off working at higher intensity levels and burning more calories while increasing your aerobic capacity and overall fitness. Many sites have started referring to this "fat burning zone" simply as the "recovery" zone...as in walking is a pretty good recovery exercise on rest days and/or in between more vigorous workouts, etc.

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