Which Do You Go By?

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  • vintageprop
    vintageprop Posts: 62 Member
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    Are you removing the BMR calories from your HRM calories? You almost always need to. For example, my BMR is 1572, so that means I burn 1.09 calories every minute by doing nothing. So if in 20 minutes your HRM says 73 calories, you then need to remove the BMR calories for that 20 minutes to get a more accurate number. So 20 * 1.09 (BMR calories / minute) = 22. So your actual calories burned are 51.

    So just work out your BMR and you can do the numbers for yourself. This might make the HRM numbers closer to the website numbers :)

    I personally would use your HRM numbers over the website numbers as your HRM knows how hard you worked. For some people Moderate effort might mean something very different to another, which makes it hard to select the correct excercise level from a generic database. However, I've actually always found the website values a bit higher than my HRM numbers.

    Good luck.

    Yes I was wondering whether to take this BMR subtracting into account as well. Thank you so much for clearing that up! I feel much better about the HRM now :)
  • MattySparky
    MattySparky Posts: 771
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    Are you removing the BMR calories from your HRM calories? You almost always need to. For example, my BMR is 1572, so that means I burn 1.09 calories every minute by doing nothing. So if in 20 minutes your HRM says 73 calories, you then need to remove the BMR calories for that 20 minutes to get a more accurate number. So 20 * 1.09 (BMR calories / minute) = 22. So your actual calories burned are 51.

    So just work out your BMR and you can do the numbers for yourself. This might make the HRM numbers closer to the website numbers :)

    I personally would use your HRM numbers over the website numbers as your HRM knows how hard you worked. For some people Moderate effort might mean something very different to another, which makes it hard to select the correct excercise level from a generic database. However, I've actually always found the website values a bit higher than my HRM numbers.

    Good luck.

    Yes I was wondering whether to take this BMR subtracting into account as well. Thank you so much for clearing that up! I feel much better about the HRM now :)

    I wouldn't worry about subtracting these "doing nothing" type calories, that's reading a little bit too much into this whole thing I think.
  • Dave198lbs
    Dave198lbs Posts: 8,810 Member
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    if you are going for an accurate number
    follow the manufacturers advice
  • Iceprincessk25
    Iceprincessk25 Posts: 1,888 Member
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    Thank you everyone for your input! I really appreciate it.
    I guess I just don't understand calories as much as I thought I did since I think burning 73 calories during 20 minutes toning exercises sounds off..

    Actually....pilates is a tough work out so I think that sounds about right.
  • vintageprop
    vintageprop Posts: 62 Member
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    Are you removing the BMR calories from your HRM calories? You almost always need to. For example, my BMR is 1572, so that means I burn 1.09 calories every minute by doing nothing. So if in 20 minutes your HRM says 73 calories, you then need to remove the BMR calories for that 20 minutes to get a more accurate number. So 20 * 1.09 (BMR calories / minute) = 22. So your actual calories burned are 51.

    So just work out your BMR and you can do the numbers for yourself. This might make the HRM numbers closer to the website numbers :)

    I personally would use your HRM numbers over the website numbers as your HRM knows how hard you worked. For some people Moderate effort might mean something very different to another, which makes it hard to select the correct excercise level from a generic database. However, I've actually always found the website values a bit higher than my HRM numbers.

    Good luck.

    Yes I was wondering whether to take this BMR subtracting into account as well. Thank you so much for clearing that up! I feel much better about the HRM now :)

    I wouldn't worry about subtracting these "doing nothing" type calories, that's reading a little bit too much into this whole thing I think.

    Yeah actually, I was starting to think that I'm thinking too much on this stuff too but I do want to get to my goal so I'll just try and not worry so much anymore and just do what I can :)
  • vintageprop
    vintageprop Posts: 62 Member
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    Thank you everyone for your input! I really appreciate it.
    I guess I just don't understand calories as much as I thought I did since I think burning 73 calories during 20 minutes toning exercises sounds off..

    Actually....pilates is a tough work out so I think that sounds about right.

    You're right. since the ones I'm doing in particular make me work pretty hard in that 20 mins. Thanks for your input!
  • Azdak
    Azdak Posts: 8,281 Member
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    There are problems with both HRM calorie numbers and listed numbers on a website or numbers shown on a piece of equipment.

    Basically, in order to assess any validity, you have to know how the numbers are calculated.

    Calories expended during an activity are based on : intensity x weight.

    For certain activities such as walking, walking on an incline, running, a cycling ergometer, or stairclimbing, the energy costs have been researched extensively and there are established formulae for calculating calories expended. The formulae are pretty simple, so I would expect that any treadmill, stepper, or bike made by a major manufacturer (e.g. Life Fitness, Precor, Technogym, Cybex, Stairmaster--will give you pretty accurate numbers.

    For other machines/activities, oxygen uptake must be measured directly on a group of subjects, and then algorithms are derived from those testing results. I know that Life Fitness has its own biomechanical testing lab and they do actual studies on every new piece of equipment they introduce. I think other manufacturers use the traditional method of farming the research out to graduate schools--or they just reuse old data.

    Even a company like Life Fitness, which does the most careful testing, only uses 50-100 subjects to derive its algorithms, so there is still a noticeable standard of error.

    I am still trying to find out more details from Polar, but from what I know of exercise physiology, I have trouble trusting the HRM numbers at all. Polar is assuming a constant and consistent HR response to exercise, and that just doesn't happen. The energy cost of an activity is constant--HR response is not.

    For example, running 6.0 mph (10 min/mile) has and energy cost of about 38 mi/kg/min or roughly 11.0 METS. The energy cost is the same from step one forward. Yet it might take 3-5 minutes for HR to reach steady state. So, for the first couple of minutes, the HRM will underestimate actual calories burned.

    Plus it doesn't seem like the HRM can take into account increases in ability. Once again, the whole point of training is that you increase your aerobic capacity. That means that, after training, a previous workload will now be easier--i.e. it will represent a lower percentage of maximum than before. From the standpoint of the HRM, the training workload now represents say 65% of max rather than 75% of max, so it will count fewer calories, even though the actual energy cost of the activity is the same.

    Polar has some built in methods for estimating VO2 max, but these also contain numerous variations which can affect accuracy.

    If you are doing unstructured activities, such as spinning or group classes, then the Polar calorie numbers probably represent a reasonable way to keep track of calories--even if the numbers aren't totally accurate, they are consistent relative to the individual, ie. the numbers will represent actual differences in your routine.

    Another caveat is with strength training. The HRM calorie numbers for strength training are pretty useless, because HR response during weight training (by that I mean "traditional" weight training) is not the same as HR response to cardio exercise and the calorie calculations do not apply.

    I know it is extremely important for people on a weight-loss program to track calories, and exercise accounts for a substantial amount of calories. It's unfortunate that we can't be more precise in calculating exercise calories. For that reason, I would definitely agree with those who say that you should be extremely cautious about "counting" exercise calories in your daily planning. Obviously, if you are doing a fairly intense 30-60 minute workout, it is significant. AND you have to be careful not to restrict calories too severely or else you may not have the fuel to work out effectively, I would just be very conservative about "adding any of those calories back in"--maybe 20%-30% of what you think you burned.
  • aprilvet
    aprilvet Posts: 724 Member
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    There are problems with both HRM calorie numbers and listed numbers on a website or numbers shown on a piece of equipment.

    Basically, in order to assess any validity, you have to know how the numbers are calculated.

    Calories expended during an activity are based on : intensity x weight.

    For certain activities such as walking, walking on an incline, running, a cycling ergometer, or stairclimbing, the energy costs have been researched extensively and there are established formulae for calculating calories expended. The formulae are pretty simple, so I would expect that any treadmill, stepper, or bike made by a major manufacturer (e.g. Life Fitness, Precor, Technogym, Cybex, Stairmaster--will give you pretty accurate numbers.


    I am still trying to find out more details from Polar, but from what I know of exercise physiology, I have trouble trusting the HRM numbers at all. Polar is assuming a constant and consistent HR response to exercise, and that just doesn't happen. The energy cost of an activity is constant--HR response is not.


    Plus it doesn't seem like the HRM can take into account increases in ability. Once again, the whole point of training is that you increase your aerobic capacity. That means that, after training, a previous workload will now be easier--i.e. it will represent a lower percentage of maximum than before. From the standpoint of the HRM, the training workload now represents say 65% of max rather than 75% of max, so it will count fewer calories, even though the actual energy cost of the activity is the same.


    Another caveat is with strength training. The HRM calorie numbers for strength training are pretty useless, because HR response during weight training (by that I mean "traditional" weight training) is not the same as HR response to cardio exercise and the calorie calculations do not apply.


    While I agree with your initial statement, I think some of your comments might be a bit mis-informed.

    First, the estimated calories burned shown on most exercise machines are estimates only, no matter what their method or research. My treadmill over-estimates my calories burned by 30-50%!!!!!:noway:

    The HRM are more accurate, but still an estimate, because they take into account your real-time heart rate, which is indicative of how hard you're working. Therefore, I consider the numbers I get during strength training to be fairly accurate. Your heart rate response to ANY effort is the same- it goes up. BUT, during strength training your heart rate goes up and down, as opposed to cardio where you tend to get up to a level and stay close to it.

    Finally, your HRM DOES take into account an increase in fitness- it records your LOWER heart rate for the same activity at the same intensity. Thus, as you become more fit, you will burn fewer calories for the same activity. This is why we need to keep pushing ourselves! If it seems too easy, it probably is!!!

    But I think the bottom line is- calorie burn estimates are just that- estimates. You need to experiment with what works best for you-- trust your exercise calories and eat them all, eat 20% less, 50% less, whatever. If you're losing at a healthy rate- or seeing positive changes in your body (sometimes results are not on the scale!), continue your current method. If you're not losing and are seriously under-eating your calories, try to bump up you cals and maybe change your routine!!!

    Good luck to all!! If it were easy, none of us would be here!:flowerforyou:
  • singfree
    singfree Posts: 1,591 Member
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    Thanks, April...finally a voice of reason!
  • aprilvet
    aprilvet Posts: 724 Member
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    Thanks, April...finally a voice of reason!

    Thanks!:blushing:
  • Chiny
    Chiny Posts: 321
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    I must be doing something wrong, I have also noticed my HRM is a lot higher than this website BUT my HRM when I initially bought it asked for my gender & age NOT my weight but this site asked for my weight. SO maybe the site is more accurate? Now I see everyone else w/a HRM put in their weight, I'm wondering about mine :frown:
  • sniffles
    sniffles Posts: 295
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    I must be doing something wrong, I have also noticed my HRM is a lot higher than this website BUT my HRM when I initially bought it asked for my gender & age NOT my weight but this site asked for my weight. SO maybe the site is more accurate? Now I see everyone else w/a HRM put in their weight, I'm wondering about mine :frown:

    What kind is it? Chest strap? Wrist only? Brand? Model?

    Maybe it's possible to measure calories burnt using just your O2 level and heart rate? Check it out on google maybe!
  • Chiny
    Chiny Posts: 321
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    I must be doing something wrong, I have also noticed my HRM is a lot higher than this website BUT my HRM when I initially bought it asked for my gender & age NOT my weight but this site asked for my weight. SO maybe the site is more accurate? Now I see everyone else w/a HRM put in their weight, I'm wondering about mine :frown:

    What kind is it? Chest strap? Wrist only? Brand? Model?

    Maybe it's possible to measure calories burnt using just your O2 level and heart rate? Check it out on google maybe!

    It's this one (no chest strap watch only)
    http://www.sportline.com/product.php?prod=7

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