Is my HMR lying to me ...........this doesnt seem right?????

collinsje308
collinsje308 Posts: 17 Member
edited November 10 in Fitness and Exercise
So usually for my cardio portion of my work out I ride the bike at the gym. But last night my quads were pretty sore due to starting a new lifting routine. So I decided to walk on the treadmill at 3.6 MPH and on a 10% incline for 30 minutes. I have a polar ft4 HMR (with a chest strap) that I wear while doing my cardio. Now I felt like walking up that incline the whole time was way more work than riding the bike was but I didn't feel that it was as taxing on my legs. And I was out of breath and sweating like a pig, but my HMR was telling my that I burned 580ish calories in that half hour. I did notice that my HR was quite a bit above what it is when I ride the bike. But still to but that much in a half hour seems like a bit much.

I am 270lbs, 6 foot 1 inch tall. And have only been really exercising and watching what I eat since October.

So I guess my question is does this seem at all possible or is my HRM trying to trick me?

Replies

  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    You were using your HRM for something that its not designed to support.

    Slow walking doesn't get it into the range here the use of HR as a proxy for calorie expenditure is meaningful.
  • Hornsby
    Hornsby Posts: 10,322 Member
    You were using your HRM for something that its not designed to support.

    Slow walking doesn't get it into the range here the use of HR as a proxy for calorie expenditure is meaningful.

    This^^
  • fit4life796
    fit4life796 Posts: 6 Member
    sometimes if the heart rate or calories seem out of the normal you may need to change the battery. There is a battery in the chest strap and on the watch too.
  • Don't get too hung up on whether it was 400 or 500 or 600 calories - half hour at 10% gradient is a good effort and as long as your heart rate was in the right zone then you`re working and that's what counts. If you`re after reassurance does the treadmill not have a calorie counter to compare?
    - As long as your not eating back every calorie you think you've expended then you`re on the right track. The treadmill forces you to keep working and you probably did work harder than you would alone on a stationary bike.
    -
  • collinsje308
    collinsje308 Posts: 17 Member
    I guess I don't understand something here....maybe someone can explain it. I always thought that a HRM measured calories burned based on your information (height, weight...etc) and your heart rate during that steady state training session. So how does the method used to get your heart rate to that range I.E. walking up hill, running, jogging, swimming.......effect calorie burn?
  • Azdak
    Azdak Posts: 8,281 Member
    You were using your HRM for something that its not designed to support.

    Slow walking doesn't get it into the range here the use of HR as a proxy for calorie expenditure is meaningful.


    It wasn't slow walking, it was walking up an incline. The aerobic cost of that workload is MORE than enough to put someone into an aerobic steady state (actually it's a higher workload than many people can even sustain).
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    A 10% incline is not steep enough to triple flat terrain caloric burn.
  • 47Jacqueline
    47Jacqueline Posts: 6,993 Member
    http://www.shapesense.com/fitness-exercise/calculators/walking-calorie-burn-calculator.aspx

    This calculator shows an 251 calorie burn for 30 minutes/@3.6 mile/10% incline, which seems more realistic.
  • Azdak
    Azdak Posts: 8,281 Member
    IF you did that workload for entire 30 minutes, and IF you DID NOT hold on to the handrails at all, then that number is still a little high, but only by about 10%.

    If that 30 min includes a warm up or cool down, or if you did use the handrails, then the overestimate is much higher.

    One of the biggest problems with HRM calorie accuracy is that they assume that everyone's max HR matches the age-predicted formula when in fact 1/3 of the population can be 10-30 beats above that number.
  • Azdak
    Azdak Posts: 8,281 Member
    I guess I don't understand something here....maybe someone can explain it. I always thought that a HRM measured calories burned based on your information (height, weight...etc) and your heart rate during that steady state training session. So how does the method used to get your heart rate to that range I.E. walking up hill, running, jogging, swimming.......effect calorie burn?

    Short version is that the type of activity, and muscle groups used can affect the relationship between heart rate and oxygen uptake. So reaching a heart rate of 150 running will result in a different oxygen uptake than a HR of 150 during swimming, or a 150 doing kettlebell swings, or a 150 doing squats, etc.
  • collinsje308
    collinsje308 Posts: 17 Member
    Azdak wrote: »
    I guess I don't understand something here....maybe someone can explain it. I always thought that a HRM measured calories burned based on your information (height, weight...etc) and your heart rate during that steady state training session. So how does the method used to get your heart rate to that range I.E. walking up hill, running, jogging, swimming.......effect calorie burn?

    Short version is that the type of activity, and muscle groups used can affect the relationship between heart rate and oxygen uptake. So reaching a heart rate of 150 running will result in a different oxygen uptake than a HR of 150 during swimming, or a 150 doing kettlebell swings, or a 150 doing squats, etc.

    Thanks for the explanation!!!
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Azdak wrote: »
    You were using your HRM for something that its not designed to support.

    Slow walking doesn't get it into the range here the use of HR as a proxy for calorie expenditure is meaningful.


    It wasn't slow walking, it was walking up an incline. The aerobic cost of that workload is MORE than enough to put someone into an aerobic steady state (actually it's a higher workload than many people can even sustain).
    Yeah, I don't think I could even do 10% incline at that speed for that amount of time and I'm not very overweight. 10% is steep. I wouldn't even call 3.6mph 'slow walking'. Though at steep inclines, it actually feels a little easier with a little speed, probably a momentum thing.

    I posted this in the other thread in the GD forum but using METS values would suggest someone your size/gender would burn just under 400 calories for that activity, or the closest they tested and list, which is slightly slower. METS values come from calorimetry tests.

  • Azdak
    Azdak Posts: 8,281 Member
    A 10% incline is not steep enough to triple flat terrain caloric burn.

    At 3.6 mph, a 10% incline will almost double the intensity. So, yeah, not triple. But, at 270lbs, 3.6/10 is enough to burn 500 Cals in 30 min. (Again, w/out handrail support).
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    Yeah, I don't think I could even do 10% incline at that speed for that amount of time and I'm not very overweight. 10% is steep. I wouldn't even call 3.6mph 'slow walking'.

    Fair enough, my benchmark for slow is <4mph in arduous terrain, particularly if one isn't loaded up with patrol order.
  • Azdak
    Azdak Posts: 8,281 Member
    Azdak wrote: »
    You were using your HRM for something that its not designed to support.

    Slow walking doesn't get it into the range here the use of HR as a proxy for calorie expenditure is meaningful.


    It wasn't slow walking, it was walking up an incline. The aerobic cost of that workload is MORE than enough to put someone into an aerobic steady state (actually it's a higher workload than many people can even sustain).
    Yeah, I don't think I could even do 10% incline at that speed for that amount of time and I'm not very overweight. 10% is steep. I wouldn't even call 3.6mph 'slow walking'. Though at steep inclines, it actually feels a little easier with a little speed, probably a momentum thing.

    I posted this in the other thread in the GD forum but using METS values would suggest someone your size/gender would burn just under 400 calories for that activity, or the closest they tested and list, which is slightly slower. METS values come from calorimetry tests.


    ACSM has standard energy prediction equations for walking, running, stair climbing, and cycle ergometry. The walking equations are pretty accurate, and calculate an energy expenditure of about 8.5 METs for walking 3.6/10 unsupported.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    edited January 2015
    Right, the compendium on Google showed a METs of 8 but that only went up to 3.5mph. 8.5 would bring him from about 384 calories to 408. :)

    Now I want to do an incline workout. :|

    Edited to add-- I just tried his 3.6/10%/30min. By 5 minutes in I had to lower the speed to 3.3. By 10 minutes I had to lower the incline to 7.5. :o The calorie estimate from my Polar reflected a METs of 7.9. My BMR estimate is .97/minute, burn estimate was 231 calories.
  • Jruzer
    Jruzer Posts: 3,501 Member
    http://www.shapesense.com/fitness-exercise/calculators/walking-calorie-burn-calculator.aspx

    This calculator shows an 251 calorie burn for 30 minutes/@3.6 mile/10% incline, which seems more realistic.

    When I ran the calculator I got 561 calories. Remember that this is GROSS burn, though. I'd take off 100 kcal or more to get net burn.

    Walking at a steep incline is difficult. I sometimes do 3-3.5 MPH at 15% and typically get about 10 kcal/minute net, but I weigh more like 160 lbs.

    vw9lSYT.png
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Jruzer wrote: »
    http://www.shapesense.com/fitness-exercise/calculators/walking-calorie-burn-calculator.aspx

    This calculator shows an 251 calorie burn for 30 minutes/@3.6 mile/10% incline, which seems more realistic.

    When I ran the calculator I got 561 calories. Remember that this is GROSS burn, though. I'd take off 100 kcal or more to get net burn.

    Walking at a steep incline is difficult. I sometimes do 3-3.5 MPH at 15% and typically get about 10 kcal/minute net, but I weigh more like 160 lbs.

    vw9lSYT.png
    Why take off 100 calories or more for a 30 minute workout? That suggests a BMR of over 3 calories per minute. Mine is under 1. OP's is probably around 1.6. Just curious!

  • rileysowner
    rileysowner Posts: 8,329 Member
    Jruzer wrote: »
    http://www.shapesense.com/fitness-exercise/calculators/walking-calorie-burn-calculator.aspx

    This calculator shows an 251 calorie burn for 30 minutes/@3.6 mile/10% incline, which seems more realistic.

    When I ran the calculator I got 561 calories. Remember that this is GROSS burn, though. I'd take off 100 kcal or more to get net burn.

    Walking at a steep incline is difficult. I sometimes do 3-3.5 MPH at 15% and typically get about 10 kcal/minute net, but I weigh more like 160 lbs.

    vw9lSYT.png
    Why take off 100 calories or more for a 30 minute workout? That suggests a BMR of over 3 calories per minute. Mine is under 1. OP's is probably around 1.6. Just curious!

    My thought exactly. 100 or more to account for BMR seems excessive for 30 minutes. A quick look at a BMR calculator using the OP's information leads to about 50 calories for half and hour.
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