Polar "Fat burn" vs "Fitness"

rainbowbow
rainbowbow Posts: 7,490 Member
edited October 6 in Health and Weight Loss
Hello all!

I have been working out with my Polar ft7 and have a question regarding the fat burn vs fitness. Does anyone know how it calculates this? Is it based purely on the low/high intensity range of my heart rate?

How accurate is this as well? Does this mean i am actually burning fat during that time period and the rest is just cardio/improving my over all fitness?

I decided to do a couple work outs last/this week to try and see how it fluctuates. I used the 30 dat shred level 1 and level 2 workouts.

Level 1 i burn 234 calories and was in the "fat burning" range for 4:14 and in the fitness range for 21:44.

Level 2 i burn 319 calories and was in the "fat burning" range for 1:54 and in the fitness range for 28:54.

Does this mean that even though i burn less calories the level 1 workout is a more effective workout for burning fat? Or would the level 2 be more beneficial for weight loss?

I am not intending on doing the whole 30 day shred and i lift at the gym and run as well i was just curious how these levels work. I am 5.8 pounds from my goal of 110. (I am getting my body fat % checked tonight but that goal is 16-18%.)

Thanks!!! <3

Replies

  • dad106
    dad106 Posts: 4,868 Member
    In all reality, you're burning fat no matter where you're heart rate is at... and you don't burn more in one zone vs the other. From what I've read on here, it seems to be equal across the board and the zones should be disregarded.

    I'm not sure how they calculate it or how accurate it is.. I have the FT7 and don't really pay a lick of attention to the zones. I do my workout and where ever my heart rate lands, it lands.. and I've lost 29 pounds that way.
  • rainbowbow
    rainbowbow Posts: 7,490 Member
    In all reality, you're burning fat no matter where you're heart rate is at... and you don't burn more in one zone vs the other. From what I've read on here, it seems to be equal across the board and the zones should be disregarded.

    I'm not sure how they calculate it or how accurate it is.. I have the FT7 and don't really pay a lick of attention to the zones. I do my workout and where ever my heart rate lands, it lands.. and I've lost 29 pounds that way.

    Yeah... :( Im just afraid that i am simply burning glycogen stores and not actually losing fat. I am wanting to get to a pretty low body fat percentage for definition. I just didnt know if that tool actually had any relevance in that aspect.
  • dad106
    dad106 Posts: 4,868 Member
    In all reality, you're burning fat no matter where you're heart rate is at... and you don't burn more in one zone vs the other. From what I've read on here, it seems to be equal across the board and the zones should be disregarded.

    I'm not sure how they calculate it or how accurate it is.. I have the FT7 and don't really pay a lick of attention to the zones. I do my workout and where ever my heart rate lands, it lands.. and I've lost 29 pounds that way.

    Yeah... :( Im just afraid that i am simply burning glycogen stores and not actually losing fat. I am wanting to get to a pretty low body fat percentage for definition. I just didnt know if that tool actually had any relevance in that aspect.

    To get to a low body fat, you need to be lifting weights.. Cardio is great and all, but you lose muscle along with the fat.

    The more muscle you have, the more calories you expend at rest... and thus the more fat you burn.
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    Technically, you're burning both fat and glycogen/glucose no matter what zone you're in. The formulas in the HRM's are based on the fact that at higher intensity/shorter duration activities you burn a higher percentage of the calories you are using from glucose/glycogen and a lower percentage from fat. And at a lower intensity/longer duration activities you burn a higher percentage of the calories you are using from fat and a lower percentage from carbs. Those formulas are based on looking at research showing the relationships between what is burned at what average heart rate. But it is averages, not necessarily exact for each individual. So, they can be used as a guideline, but don't count on them to be 100% accurate for each individual. Also, the zones are based on the % of calories burned from each source, not total calories burned or even total calories burned from fat or carbs. You can burn more fat calories from a higher intensity then you can at a lower intensity if you burn more calories. For example, if you walk for 30 minutes and burn 200 calories and 30% of them are from carbs and 70% of them are fat, then you burned 140 calories from fat and 60 calories from carbs. But if you run for 30 minutes and burn 600 calories and 70% of them are carbs and 30% are fat, then you've burned 180 calories from fat and 420 calories from carbs. Both workouts are 30 minutes long, but you can cover more ground running and burn more calories, and more calories from fat because of burning more.

    So, long story short, work at the highest intensity you feel comfortable. Don't work so hard that you can't breathe or feel bad while doing it. You should still be able to talk while working out. As your heart health and the ability of the rest of your body to provide and process oxygen improves, you will be able to workout at a higher intensity. Just progress at your own pace and don't stress what the HRM says.
  • rainbowbow
    rainbowbow Posts: 7,490 Member
    Yep. That's what im doing. :)

    I just noticed the feature on my HRM and decided to see what it does with a workout video i happened to have handy.
    In all reality, you're burning fat no matter where you're heart rate is at... and you don't burn more in one zone vs the other. From what I've read on here, it seems to be equal across the board and the zones should be disregarded.

    I'm not sure how they calculate it or how accurate it is.. I have the FT7 and don't really pay a lick of attention to the zones. I do my workout and where ever my heart rate lands, it lands.. and I've lost 29 pounds that way.

    Yeah... :( Im just afraid that i am simply burning glycogen stores and not actually losing fat. I am wanting to get to a pretty low body fat percentage for definition. I just didnt know if that tool actually had any relevance in that aspect.

    To get to a low body fat, you need to be lifting weights.. Cardio is great and all, but you lose muscle along with the fat.

    The more muscle you have, the more calories you expend at rest... and thus the more fat you burn.
  • rainbowbow
    rainbowbow Posts: 7,490 Member
    Thanks! That is exactly what i was curious about. :D I'll keep lifting heavy and doing HIT. Thanks everyone! <3
    Technically, you're burning both fat and glycogen/glucose no matter what zone you're in. The formulas in the HRM's are based on the fact that at higher intensity/shorter duration activities you burn a higher percentage of the calories you are using from glucose/glycogen and a lower percentage from fat. And at a lower intensity/longer duration activities you burn a higher percentage of the calories you are using from fat and a lower percentage from carbs. Those formulas are based on looking at research showing the relationships between what is burned at what average heart rate. But it is averages, not necessarily exact for each individual. So, they can be used as a guideline, but don't count on them to be 100% accurate for each individual. Also, the zones are based on the % of calories burned from each source, not total calories burned or even total calories burned from fat or carbs. You can burn more fat calories from a higher intensity then you can at a lower intensity if you burn more calories. For example, if you walk for 30 minutes and burn 200 calories and 30% of them are from carbs and 70% of them are fat, then you burned 140 calories from fat and 60 calories from carbs. But if you run for 30 minutes and burn 600 calories and 70% of them are carbs and 30% are fat, then you've burned 180 calories from fat and 420 calories from carbs. Both workouts are 30 minutes long, but you can cover more ground running and burn more calories, and more calories from fat because of burning more.

    So, long story short, work at the highest intensity you feel comfortable. Don't work so hard that you can't breathe or feel bad while doing it. You should still be able to talk while working out. As your heart health and the ability of the rest of your body to provide and process oxygen improves, you will be able to workout at a higher intensity. Just progress at your own pace and don't stress what the HRM says.
  • ryanodell81
    ryanodell81 Posts: 1
    I agree with the fact that you're burning both fat and glycogen/glucose no matter what zone you're in. However the problem is that you are not using the right values for compairing high intensity to low intensity when you use 60% fat burn compared to 30% fat burn based on the website below:

    http://www.thewalkingsite.com/thr.html

    I was thinking the same thing as you that you would be better off working out at the higher level and I even went as far as to create a excel spreadsheet based on some elliptical information I had; light intensity 0.06 cal/min/lb, moderate intensity 0.075 cal/min/lb and vigorous intensity 0.091 cal/min/lb. I used both the website above for the % fat burn and the elliptical information and built a spreadsheet from 1 to 90 minutes for both fat calories burned and total calories burned. Due to the disparity between light intensity (85% fat burn) and vigorous intensity (15% fat burn) there is no question why people recommend low intensity workout for improved fat burn. I am 250lbs and with my calculations above it would take 24 minutes at low intensity (85% fat burn) to burn 308 fat calories, 32 minutes at moderate intensity (50% fat burn) to burn 302 calories and a whapping 88 minutes at high intensity (15% fat burn) to burn 302 calories during a high intensity workout. I have no medical background but I am an engineer and familar with equations and excel.
    Technically, you're burning both fat and glycogen/glucose no matter what zone you're in. The formulas in the HRM's are based on the fact that at higher intensity/shorter duration activities you burn a higher percentage of the calories you are using from glucose/glycogen and a lower percentage from fat. And at a lower intensity/longer duration activities you burn a higher percentage of the calories you are using from fat and a lower percentage from carbs. Those formulas are based on looking at research showing the relationships between what is burned at what average heart rate. But it is averages, not necessarily exact for each individual. So, they can be used as a guideline, but don't count on them to be 100% accurate for each individual. Also, the zones are based on the % of calories burned from each source, not total calories burned or even total calories burned from fat or carbs. You can burn more fat calories from a higher intensity then you can at a lower intensity if you burn more calories. For example, if you walk for 30 minutes and burn 200 calories and 30% of them are from carbs and 70% of them are fat, then you burned 140 calories from fat and 60 calories from carbs. But if you run for 30 minutes and burn 600 calories and 70% of them are carbs and 30% are fat, then you've burned 180 calories from fat and 420 calories from carbs. Both workouts are 30 minutes long, but you can cover more ground running and burn more calories, and more calories from fat because of burning more.

    So, long story short, work at the highest intensity you feel comfortable. Don't work so hard that you can't breathe or feel bad while doing it. You should still be able to talk while working out. As your heart health and the ability of the rest of your body to provide and process oxygen improves, you will be able to workout at a higher intensity. Just progress at your own pace and don't stress what the HRM says.
  • cmb0267
    cmb0267 Posts: 7
    I agree with the fact that you're burning both fat and glycogen/glucose no matter what zone you're in. However the problem is that you are not using the right values for compairing high intensity to low intensity when you use 60% fat burn compared to 30% fat burn based on the website below:

    http://www.thewalkingsite.com/thr.html

    I was thinking the same thing as you that you would be better off working out at the higher level and I even went as far as to create a excel spreadsheet based on some elliptical information I had; light intensity 0.06 cal/min/lb, moderate intensity 0.075 cal/min/lb and vigorous intensity 0.091 cal/min/lb. I used both the website above for the % fat burn and the elliptical information and built a spreadsheet from 1 to 90 minutes for both fat calories burned and total calories burned. Due to the disparity between light intensity (85% fat burn) and vigorous intensity (15% fat burn) there is no question why people recommend low intensity workout for improved fat burn. I am 250lbs and with my calculations above it would take 24 minutes at low intensity (85% fat burn) to burn 308 fat calories, 32 minutes at moderate intensity (50% fat burn) to burn 302 calories and a whapping 88 minutes at high intensity (15% fat burn) to burn 302 calories during a high intensity workout. I have no medical background but I am an engineer and familar with equations and excel.
    ****
    This is tremendous information! I'd been busting it on high-intensity cardio for about two months before a Physical Trainer advised me to get an HRM and focus on the fat burn zone. He recommended a minimum 3:1 time ratio of fat burn: fitness and to extend my "workouts" to at least 45 minutes, preferably 60. I say "workouts" because it doesn't seem like much work to plod along at maximum fat burn for 45 minutes (2.1 mph at 4% incline), but in the two weeks I've followed this direction my legs have changed shape dramatically - far more so than had happened in the previous two months - even though I haven't lost weight at an increased rate. Funny bit of business. Your post clarifies a lot. Thanks.
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