HRM - disappointed (confused)

sweetpea7441
sweetpea7441 Posts: 149 Member
edited December 19 in Fitness and Exercise
Hi. I got my HRM last week and was so excited to use it today for first time at gym.

I thought my calorie amount would increase... It didn't.

I first did my warm up of 8min cycling - the calorie loss on my HRM was equal to the one of the bike. Then I did 30min of rotex - alternating between fast and slow. Slow heartbeat was about 126-130, fast heart beat was about 149-155. I'm 160cm, 37 and 63.3kg.

I totally expected my calorie usage to be higher then normal (due to my own HRM and also due to really concentrating no fast slow fast slow). Going based on the machine it was normally about 200 calories burned.

Today the machine told me 270 cal burned, yay!! But my HRM said 217 calories... :-( So I have used the 217 for MFP, but WHY???

Why was it such a short amount higher? I know the gym machine is based on me personally, but am really disappointed in the amount on my HRM.

Are my slow and fast heart beats the wrong amounts? they should have a bigger gap or smaller gap between? First time I'm really doing fast slow fast slow, so fast was for about 5min and slow was for about 2min. That wrong?

Any advice is greatly welcome. I need to burn calories!!! :-)

Thanks.

Replies

  • SteveTries
    SteveTries Posts: 723 Member
    All caloric burn estimates, be they HRM's, gym machines, online calculators or an iphone app are just that; estimates.

    Each uses an algorithm that is based on clinical trials with a sample population. There have been many such trials and as such many different algorithms have been produced. None of them are truly accurate because everyone is different to that sample population but they do give us a decent guide.

    I personally believe that most overestimate because manufacturers want people to buy their products and we as consumers really want to hear that we are burning large amounts of calories - your post here is absolute proof of that!

    HR monitors are generally believed to me the more accurate tool to use but it's certainly not going to be exact.

    I understand your dissapointment, but perhaps your expectations weren't realistic. I'd also point out that your consternation is only over 50cals, that's a pretty tiny amount - it's highly unlikely your calorie intake tracking is accurate to 50cals over the course of a day (food labels are allowed to be up to 20% out to account for product variance).
  • islaybower
    islaybower Posts: 57
    Most gym machines over-estimate, so your HRM is probably more accurate. Neither is absolutely perfect, but HRMs are generally more accurate than gym machines.
  • sweetpea7441
    sweetpea7441 Posts: 149 Member
    Thanks, I'm going to stick with what my HRM tells me. I really need to increase the time that I exercise, but am seeing physio for my back, so am taking it slow and easy... Hmmmm. One day I will be a trim and healthy me ... :-)
  • XXXMinnieXXX
    XXXMinnieXXX Posts: 3,459 Member
    Do some Zumba if you can! that gets a great burn! x
  • Fit4_Life
    Fit4_Life Posts: 828 Member
    If you have a chest band, THAT needs to be secure and snug around your chest to fit comfortably. I have found that my chest band was not secure tightly (comfortable) that my HRM was not accurate. It's all good now! :glasses:
  • rml_16
    rml_16 Posts: 16,414 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...
  • dad106
    dad106 Posts: 4,868 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    Cause HRM's(Like the cheap ones) report higher calorie estimates... like Timex for example, can report thousands of calories burned in a short period of time.

    To OP:
    What sort of HRM is it? Does it have a strap?

    If it does, then it is correct in it's estimating.. sorry it's disappointing, but I'm sure you'd rather underestimate than overestimate.
  • SassyCalyGirl
    SassyCalyGirl Posts: 1,932 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!
  • Azdak
    Azdak Posts: 8,281 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.
  • SassyCalyGirl
    SassyCalyGirl Posts: 1,932 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.

    Um-yes it does. But you are correct in stating that your HRM settings need to be updated. Through personal experience my calories burns are much lower doing the same exercise.
  • Azdak
    Azdak Posts: 8,281 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.

    Um-yes it does. But you are correct in stating that your HRM settings need to be updated. Through personal experience my calories burns are much lower doing the same exercise.

    Um...no it doesn't, except in a very minor way that the average person does not experience. The "greater efficiency equals less calories burned" is classic BroScience--at least the way that it is commonly used.

    The decreased heart rate that people experience when performing exercise over time does not mean that VO2 (and, thus calorie burn) is decreasing. It just means that the VO2 of the exercise being performed represents a smaller percentage of one's max becuase the max has increased. The confusion results because of the difference between fixed and relative intensity.

    Calories burned = intensity (VO2) x body wt. An 80 kg person running at 6 mph will burn 400 calories in 30 min. In the beginning, that effort might represent 75% of their maximum. With training, the maximum increases, so heart rate decreases. However, running 6 mph will still burn 400 calories in 30 min (assuming no change in weight). The intensity of the effort has not changed--it just feels easier becuase now it might only represent 55%-65% of maximum. Since the HRM doesn't know the difference, it just assumes the lower HR is due to working at a lower intensity and shows a lower calorie burn.
  • SassyCalyGirl
    SassyCalyGirl Posts: 1,932 Member
    we will just have to agree to disagree.
  • hbrittingham
    hbrittingham Posts: 2,518 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.

    Um-yes it does. But you are correct in stating that your HRM settings need to be updated. Through personal experience my calories burns are much lower doing the same exercise.

    I've noticed that in my own workouts, too. The better condition I am in, the lower the calorie burn for the exact same exercise.
  • Hellbent_Heidi
    Hellbent_Heidi Posts: 3,669 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.

    Um-yes it does. But you are correct in stating that your HRM settings need to be updated. Through personal experience my calories burns are much lower doing the same exercise.

    I've noticed that in my own workouts, too. The better condition I am in, the lower the calorie burn for the exact same exercise.
    Same here...as my weight dropped (and I updated my HRM accordingly), it became harder and harder to reach the higher calorie burns I used to be able to get when I was 25 or 30 lbs heavier, so YES, it did change for me. Now that I'm more fit, my heart rate recovery has improved significantly as well.
  • wellbert
    wellbert Posts: 3,924 Member
    Wait, did you think that a HRM would make you burn more calories?
  • HeidiHoMom
    HeidiHoMom Posts: 1,393 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    I don't understand either.

    Did you think it was going to tell you that you burned 500 calories for walking for 20 mins?
  • SassyCalyGirl
    SassyCalyGirl Posts: 1,932 Member
    I don't understand why you thought wearing an HRM would cause you to burn more calories ...

    this^

    and remember as you become more fit-your heart becomes more efficient which equals less calories burned. Stick to it!

    No it doesn't--it just means your HRM settings need to be updated.

    Um-yes it does. But you are correct in stating that your HRM settings need to be updated. Through personal experience my calories burns are much lower doing the same exercise.

    I've noticed that in my own workouts, too. The better condition I am in, the lower the calorie burn for the exact same exercise.
    Same here...as my weight dropped (and I updated my HRM accordingly), it became harder and harder to reach the higher calorie burns I used to be able to get when I was 25 or 30 lbs heavier, so YES, it did change for me. Now that I'm more fit, my heart rate recovery has improved significantly as well.

    Thank you!
  • SteveTries
    SteveTries Posts: 723 Member

    I've noticed that in my own workouts, too. The better condition I am in, the lower the calorie burn for the exact same exercise.

    And this is where your HRM can help you out a little right? So if your 5km, 30min jog on the treadmill burnt 400 when less fit and 350 when fitter you need to change the parameters (speed or distance) to keep your heart rate up at the same level so you are still working as hard as you were before.
  • sweetpea7441
    sweetpea7441 Posts: 149 Member
    Noooo, I didn't expect the HRM to automatically mean I burnt more...

    But I was hoping for a more positive reading due to using it - as its more accurate and set to my specifics, plus I mentioned that for the first time I did slow fast slow fast (something like HIIT?) so I figured that would help as well. I didn't expect a huge change, but something! :-)

    I understand what SJB74UK says - better condition doing same exercise means less calories burned. I know its also good to keep changing what you do - as your body gets used to your workout and doesn't mean as much. But does this mean making it a longer workout or a harder/heavier workout?

    Thanks.
  • hbrittingham
    hbrittingham Posts: 2,518 Member

    I've noticed that in my own workouts, too. The better condition I am in, the lower the calorie burn for the exact same exercise.

    And this is where your HRM can help you out a little right? So if your 5km, 30min jog on the treadmill burnt 400 when less fit and 350 when fitter you need to change the parameters (speed or distance) to keep your heart rate up at the same level so you are still working as hard as you were before.

    Exactly. I believe that's what SassyCalyGirl was saying above to the OP.
  • Anonymou5
    Anonymou5 Posts: 92
    Just treat the read out from the HRM as gold and don't be dissapointed just train harder or longer...
  • omma_to_3
    omma_to_3 Posts: 3,265 Member
    I've found my HRM shows I burn far MORE calories than my treadmill said (which didn't account for my weight/gender). However, I am far more overweight and quite a ways from the "average" size a machine would assume. You are very close to the "average" a machine would have programmed in it. Given that, it doesn't surprise me that your HRM showed a slightly lower burn.
  • omma_to_3
    omma_to_3 Posts: 3,265 Member
    Oh, and I definitely see a smaller calorie burn the more fit I become. How could you not as you become more cardiovascularly fit? My average heart rate is less, my burn is less. I purposely have my HRM set to below my actual weight, just for a little added protection from overestimating. I will be changing it again soon as I've almost reached that weight.
  • Azdak
    Azdak Posts: 8,281 Member
    As I mentioned before, becoming more fit does not decrease your calorie burn in any practical way. The energy cost of an aerobic activity (e.g. running at a certain speed) is relatively constant. In other words, the energy cost of running 6 mph is about 10 METs. (a MET is a unit of aerobic intensity). That energy cost is basically the same, no matter who is doing the activity (exception being very obese individuals). The calories burned will be different because of differences in body weight--heavier people burn more. But the intensity does not change significantly because your fitness level increases. It is still 10 METs.

    People think their calorie burn is decreasing because the number on the HRM goes down, but that is an erroneous conclusion. HRMs do not measure calories--they estimate calories based on the heart rate they detect combined with the reference (setup) information you provide. If that information (e.g. maximum aerobic fitness level or VO2max) changes--as it does with training--then the HRM numbers are no longer based on accurate information. Garbage in, garbage out. You cannot use an HRM calorie number as "proof" of anything.

    Now if weight decreases, then, yes, calories expended will decrease as well. That's because smaller bodies burn fewer calories than larger ones.

    In any case, the combination of weight loss and improved fitness should result in a person working HARDER, not staying the same. If you keep seeing lower HR averages for your workouts you should be increasing the effort level.

    For more detail, check this out:

    http://www.myfitnesspal.com/blog/Azdak/view/calories-burned-during-exercise-it-s-the-intensity-not-the-heart-rate-that-counts-26524
  • SteveTries
    SteveTries Posts: 723 Member
    I understand what SJB74UK says - better condition doing same exercise means less calories burned. I know its also good to keep changing what you do - as your body gets used to your workout and doesn't mean as much. But does this mean making it a longer workout or a harder/heavier workout?


    Well sort of, but NO. It's not harder is it, because you've adapted and perform better. For example, I started jogging earlier this year and have reduced my 5km time from over 30 mins to 25. It's not a harder workout, it's the same because I'm fitter. This is where your HRM keeps you performant. You remove the focus on the time/distance element and turn it onto the workrate of your body.
  • sweetpea7441
    sweetpea7441 Posts: 149 Member
    Thanks to everyone for their detailed and patient replies. :flowerforyou:
This discussion has been closed.

Categories