HRM told me wrong...

sabi82much
sabi82much Posts: 5 Member
edited November 17 in Health and Weight Loss
But it's all my fault :'(:'(
I forgot to set my weight and height and have been getting completely incorrect info from my polar ft7.

I am actually 5'3 and 146lbs, but the polar thought I was 5`7ish and abt 132lbs (it was in metric, these are conversions). My burns have been AMAZING.... According to the polar. But now I know better :s anyone have any idea how off my stats might be?

Replies

  • TimothyFish
    TimothyFish Posts: 4,925 Member
    Heart rate monitors do a poor job of estimating calorie burns anyway.
  • Tacklewasher
    Tacklewasher Posts: 7,122 Member
    Honestly, 132 to 146 is probably within the error rate of the strap anyway. Consider it close enough, fix the error and move on. It really won't have impacted your weight loss much.
  • sabi82much
    sabi82much Posts: 5 Member
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.
  • fitmom4lifemfp
    fitmom4lifemfp Posts: 1,572 Member
    edited March 2017
    Here are a couple of charts, I would assume that they are fairly accurate for the weights given. (My HRM actually shows lower numbers than some of these on the charts, so I'll stick with my HRM.)

    http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/exercise/art-20050999?pg=2

    http://www.health.harvard.edu/diet-and-weight-loss/calories-burned-in-30-minutes-of-leisure-and-routine-activities
  • sabi82much
    sabi82much Posts: 5 Member
    @fitmom4lifemfp thanks!!
  • ashleighs148
    ashleighs148 Posts: 335 Member
    edited March 2017
    sabi82much wrote: »
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.

    They might not be super accurate but they're the most accurate you're going to get, definitely better than mfp or machine estimates (obviously with the right height and weight in).

  • erickirb
    erickirb Posts: 12,294 Member
    edited March 2017
    ashleighs148 wrote: »
    sabi82much wrote: »
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.

    They might not be super accurate but they're the most accurate you're going to get, definitely better than mfp or machine estimates (obviously with the right height and weight in).

    They are a good estimator under certain conditions. Steady state cardio. That said if you can't set your Max HR or V02Max in the embedded calculation they will be less accurate. I don't believe the Ft7 allows you to modify those imputs. In addition to that HRMs calculate total cals burned, some of which you would have burned had you not exercised and are already included in your allowance. Assuming you burn 1.25 cals at rest, and in an hour the HRM said you burned 500 cals, that would be only 410, as it counts the 1.25*60mins that are already your in MFP in your daily allowance.

    I would also add that a treadmill's machine where you enter your own age, weight, etc, will be better than your hrm, as it measures work done, not perceived work done, which an HRM does.
  • Machka9
    Machka9 Posts: 25,714 Member
    I use Strava with my HRM.

    Interestingly, my heart rate goes way up right before and in the first few metres of a climb. Stress. Anticipation.

    And then it settles down once I'm actually climbing.

    Do I burn a whole lot of calories before I reach the climb? Nope. But my HRM would indicate that I do.


    For calories burned, I refer to Strava, MFP, and my own calculations. Then I go with the lowest choice. Works for me.
  • TimothyFish
    TimothyFish Posts: 4,925 Member
    sabi82much wrote: »
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.

    Without knowing what you are trying to accomplish I have no way of knowing what is best. It could be that a HRM is your best option for what you want to do, but the nature of how the heart works makes HRMs inaccurate. Measuring your oxygen usage is the most accurate, but it requires wearing a mask. Power meters can come fairly close, but they require a few assumptions about the efficiency of your metabolism. GPS units can also get fairly close by measuring distance traveled and elevation gain over time.
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    If your polar thought you were lighter/leaner than you actually are, your estimates were probably lower than they "should" have been. That's not a bad thing.

    Or am I missing something?
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    I wouldn't say they do a poor job... in some cases, they can do quite well. I think unreliable is probably a better word.
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    sabi82much wrote: »
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.

    There isn't really a better way, at least not most of the time.

    The best thing you can do is be consistent. If you like your HRM, then use it. But use it consistently, and log consistently. All this weight loss and cals is vs cals out stuff is just a series of estimates. If, over time, your expected results aren't reasonably close to your actual results, then something in your estimates is off. Evaluate, tweak, and try again.
  • jeepinshawn
    jeepinshawn Posts: 642 Member
    Were you happy with your weight loss for that time period? If not eat less. I didn't get a fitbit until I had lost the majority of my 120lbs. My fitbit broke recently and I replaced it with a Garmin vivofit hr. They are nice toys that help keep you motivated, but completely unnecessary for weight loss. Just follow the mfp recommendations, log accurately, and ignore the calorie burns from your device.
  • mlsh1969
    mlsh1969 Posts: 138 Member
    jjpptt2 wrote: »
    If your polar thought you were lighter/leaner than you actually are, your estimates were probably lower than they "should" have been. That's not a bad thing.

    Or am I missing something?

    Exactly
  • sabi82much
    sabi82much Posts: 5 Member
    edited March 2017
    Thanks for the info, everyone :)

    I do a mix of workouts... Steady state, intervals and strength. How would the different activities affect my calorie burns shown?

    Any links with info would be great too :)
  • NorthCascades
    NorthCascades Posts: 10,968 Member
    sabi82much wrote: »
    But it's all my fault :'(:'(
    I forgot to set my weight and height and have been getting completely incorrect info from my polar ft7.

    This doesn't make any sense. Your FT7 doesn't need to know if you're a boy or a girl or what your favorite color is to tell you how fast your heart is beating.
  • NorthCascades
    NorthCascades Posts: 10,968 Member
    WandaMM1 wrote: »
    My personal belief is that HRMs may not be accurate but they should be consistent. This provides a tool, then, to compare your performance (burn) from one day to another. Things like what you ate and how rested you are can greatly impact how you feel during your workout. HRMs can keep you honest with yourself.

    I did an experiment recently, without meaning to. I skied the same route with the same level of (perceived) exertion, once with my chest strap, and one day I forgot it so had to rely on the wrist heart rate sensor. I got wildly different answers:

    Saturday: 429 kCal/hour, 4 hours recovery, 1 new speed record (wrist sensor)
    https://connect.garmin.com/modern/activity/1536290485

    Sunday: 750 kCal/hour, 53 hours recovery, 2 new speed records (chest strap)
    https://connect.garmin.com/modern/activity/1538136970
  • fitmom4lifemfp
    fitmom4lifemfp Posts: 1,572 Member
    edited March 2017
    sabi82much wrote: »
    Thanks for the info, everyone :)

    I do a mix of workouts... Steady state, intervals and strength. How would the different activities affect my calorie burns shown?

    Any links with info would be great too :)

    There simply is no good way anyone can tell you what you burn - it's too hard to measure all the different exercises that go into individual workouts, for different people. This article discusses that.

    http://www.sparkpeople.com/blog/blog.asp?post=you_asked_how_many_calories_does_strength_training_burn

    I think the best you can do is break down your workouts into pieces, look up each *part* on a site something like this (this is set to dumbbell curls for a 150 pound person, for 10 min).

    http://www.fitclick.com/calories_burned?Biceps&bpid=6#.WNWSLTvyvct

    Then piece together your workout, and see what you wind up with. I've done this enough that I can come up with a good *guesstimate* based on the length of my workout and my level of effort.

  • sabi82much
    sabi82much Posts: 5 Member
    fitmom4lifemfp wrote: »
    sabi82much wrote: »
    Thanks for the info, everyone :)

    I do a mix of workouts... Steady state, intervals and strength. How would the different activities affect my calorie burns shown?

    Any links with info would be great too :)

    There simply is no good way anyone can tell you what you burn - it's too hard to measure all the different exercises that go into individual workouts, for different people. This article discusses that.

    http://www.sparkpeople.com/blog/blog.asp?post=you_asked_how_many_calories_does_strength_training_burn

    I think the best you can do is break down your workouts into pieces, look up each *part* on a site something like this (this is set to dumbbell curls for a 150 pound person, for 10 min).

    http://www.fitclick.com/calories_burned?Biceps&bpid=6#.WNWSLTvyvct

    Then piece together your workout, and see what you wind up with. I've done this enough that I can come up with a good *guesstimate* based on the length of my workout and my level of effort.

    Sounds good... Thanks :)
  • Psychgrrl
    Psychgrrl Posts: 3,177 Member
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    Mine has been really helpful for losing weight and now maintaining weight. Seems accurate for me.
  • ashleighs148
    ashleighs148 Posts: 335 Member
    erickirb wrote: »
    ashleighs148 wrote: »
    sabi82much wrote: »
    TimothyFish wrote: »
    Heart rate monitors do a poor job of estimating calorie burns anyway.

    So then.... what would a better way be?

    Good to know it's not as big a difference as I thought it'd be.

    They might not be super accurate but they're the most accurate you're going to get, definitely better than mfp or machine estimates (obviously with the right height and weight in).

    They are a good estimator under certain conditions. Steady state cardio. That said if you can't set your Max HR or V02Max in the embedded calculation they will be less accurate. I don't believe the Ft7 allows you to modify those imputs. In addition to that HRMs calculate total cals burned, some of which you would have burned had you not exercised and are already included in your allowance. Assuming you burn 1.25 cals at rest, and in an hour the HRM said you burned 500 cals, that would be only 410, as it counts the 1.25*60mins that are already your in MFP in your daily allowance.

    I would also add that a treadmill's machine where you enter your own age, weight, etc, will be better than your hrm, as it measures work done, not perceived work done, which an HRM does.

    My polar takes into account resting HR though it's not the ft7, not sure about that one. The calories you burn at rest is partly why you don't eat 100% back. Also, machines usually give me double the amount of calories compared to my polar HRM, sometimes 900+ for a spin class which for a 5'3 girl in 45 minutes is just crazy. Always found my HRM to be much more reasonable.
  • sijomial
    sijomial Posts: 19,809 Member
    edited March 2017
    sabi82much wrote: »
    Thanks for the info, everyone :)

    I do a mix of workouts... Steady state, intervals and strength. How would the different activities affect my calorie burns shown?

    Any links with info would be great too :)

    Steady state cardio - if you have a close to average exercise HR then a basic HRM may well give you a reasonable estimate, Useable even if not accurate. Get hot, dehydrated or if you are an outlier then accuracy will suffer.
    Depending on what your steady state cardio actually is (Rowing? Running? Cycling?) there may be a better way to get a reasonable estimate.

    Intervals - as your HR is elevated during the recovery periods your HR is higher during those periods than the actual work you are doing. Depending on the intensity/duration of your intervals the most likely outcome is somewhere between too high to very high estimates. If you are unfit with a slow recovery then ridiculously high might be the outcome.

    Strength training - completely inappropriate to try and get a calorie estimate from a HRM, it's not an aerobic exercise so the work done has no relationship to oxygen uptake (HR is used as a convenient proxy for oxygen uptake). The calorie burn is primarily the volume of weight lifted x distance. Have fun trying to be accurate with that! (Just use the strength training estimate in the database would be my suggestion.)
  • fitmom4lifemfp
    fitmom4lifemfp Posts: 1,572 Member
    sabi82much wrote: »
    fitmom4lifemfp wrote: »
    sabi82much wrote: »
    Thanks for the info, everyone :)

    I do a mix of workouts... Steady state, intervals and strength. How would the different activities affect my calorie burns shown?

    Any links with info would be great too :)

    There simply is no good way anyone can tell you what you burn - it's too hard to measure all the different exercises that go into individual workouts, for different people. This article discusses that.

    http://www.sparkpeople.com/blog/blog.asp?post=you_asked_how_many_calories_does_strength_training_burn

    I think the best you can do is break down your workouts into pieces, look up each *part* on a site something like this (this is set to dumbbell curls for a 150 pound person, for 10 min).

    http://www.fitclick.com/calories_burned?Biceps&bpid=6#.WNWSLTvyvct

    Then piece together your workout, and see what you wind up with. I've done this enough that I can come up with a good *guesstimate* based on the length of my workout and my level of effort.

    Sounds good... Thanks :)

    Also remember that doing three sets of curls, over 15 minutes, is not looked up as "15 min of curls". Time each set. Do the math. For instance, I do 3 sets of standing dumbbell curls. I might be there for 10 min or so. Depends on how much time I rest in between sets. But each set only lasts 30 sec, for me. So my calories would be based on 1:30 of curls. This is why it's a difficult thing to just estimate, for other people. But measuring your actual time and adding it up is about as accurate as you will get.
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