HRM & BMR Double Counting?

AllanMisner
AllanMisner Posts: 4,140 Member
edited November 2024 in Health and Weight Loss
I just started using a HRM and the thought occurred to me. My BMR, as calculated on MFP is 2400 calories a day. That works out to 100 calories per hour (obviously more during my waking hours, less when I'm asleep). If I take the number directly from my HRM after an hour of exercise, am I not double counting those roughly 100 calories?

And if I am, then on a 2 hour or longer period of exercise, I could be double counting upwards to 500 calories. If I eat back all of my calories per MFP, then I am actually not getting the deficit calories for weight loss.

Am I over-thinking this?


ETA: They say there isn't a single new thought in all the world. Looks like someone else went down this thought process before:
http://www.myfitnesspal.com/topics/show/192032-excel-formuals-to-compute-bmr-adjust-hrm-exercise-calories?hl=HMR,+BMR#posts-2544502

Replies

  • OSC_ESD
    OSC_ESD Posts: 752 Member
    Hey ! Your BMR is your resting " state " ... what your body will burn when doing absolutely nothing ! Imagine laying in bed all day long ... that is your BMR.

    Forget about your BMR ... Go with the HRM and get accurate numbers burned or fairly close to it and base your daily intake on just that. Here is a great read about it :

    http://www.caloriesperhour.com/tutorial_BMR.php

    Hope this clears it up for ya ! :wink:
  • Angelabec
    Angelabec Posts: 505 Member
    I solve that problem by not eating my exercise calories, although you will be told a hundred times over that that's not the right way to go. If I were to though, I would definitely deduct some from the figure that I was given.
  • AllanMisner
    AllanMisner Posts: 4,140 Member
    I agree that the HRM is more accurate. What I was thinking was that the assumed BMR was across a full 24 hours. I still feel there is a little overlap/double counting if you don't remove the BMR calories from your total.

    For example:

    My estimated BMR is 2400.
    If I work out for three hours and my HRM says 2000 (yes, this is realistic for me), and I add the two (as MFP does), I would come to 4400 total. My target on the site would be 3900 (assuming 1 lb per week loss). But, during those three hours I was working out, I would be doubling up if I don't back out three hours of BMR (which, during waking hours would be more than 100 per hour). As such, my double count would approximate my planned deficit.

    Granted these are all estimates, but I think there might be a case for not eating back every one of your workout calories (although I think you should eat much of them back to keep your metabolism running well).
  • OSC_ESD
    OSC_ESD Posts: 752 Member
    I'm thinking that those calories burned on your HRM are from your increased heart rate. Where as your resting rate is " normal " burn. The HRM is calculating during activity. If you wore it all day long .... you could see the difference between your BMR and actual calories burned over a 24 hr period. Remember that a BMR means doing absolutely NOTHING.

    When your working out for 20, 30 or even 60 minutes at an increased rate ... you will be burning additional calories on top of that BMR number.

    Think about this ... Your BMR means doing nothing ... but really, who does nothing all day long ???? So even if you didn't workout at all today .... your calories burned would well exceed from just walking around and doing what is normal activity for you ! There really is no way to monitor this unless you wore the HRM 24/7 just to see what a normal day does for you. But I do know I wouldn't subtract any caolries out of my HRM number ... unless your going to add in all the " normal " calories burned throughout the day while doing normal activities that is outside of your BMR !

    Honestly ... too much thought on this one. The HRM is a great way to get more accurate numbers rather than basing your burns on estimates from a database that is designed for " one fits most ". We all burn at a different rate ... so many factors involved. Just take it day by day and see where you land.

    Fact is I will never eat back all my exercise calories ... but damn close. I learned the hard way that fuel is more important than any number on my scale. The idea for me is simple ... " Healthy Lifestyle " ... by doing it the right way, it may take longer to get to the bottom number ... but I will be a well oiled machine in the best shape of my life from doing it right !

    You know me well enough to know that this is such a " huge " part of my journey .... and where I am now has caused me to re-evaluate the entire process. A plateau will do that to you ... makes you stronger .... wiser ! :wink:

    I wish you all the best in this process and know you will figure out what works for you ! Your just as determined as I am ! :flowerforyou:
  • erickirb
    erickirb Posts: 12,294 Member
    I agree that the HRM is more accurate. What I was thinking was that the assumed BMR was across a full 24 hours. I still feel there is a little overlap/double counting if you don't remove the BMR calories from your total.

    For example:

    My estimated BMR is 2400.
    If I work out for three hours and my HRM says 2000 (yes, this is realistic for me), and I add the two (as MFP does), I would come to 4400 total. My target on the site would be 3900 (assuming 1 lb per week loss). But, during those three hours I was working out, I would be doubling up if I don't back out three hours of BMR (which, during waking hours would be more than 100 per hour). As such, my double count would approximate my planned deficit.

    Granted these are all estimates, but I think there might be a case for not eating back every one of your workout calories (although I think you should eat much of them back to keep your metabolism running well).

    Really the number you should back out for your HRM is maintenance calories, as BMR is only what you would burn in a coma, so if you were going to sleep instead of workout then use BMR, if would would have been awake use Maintenance, this means you will back out even more cals, but is the correct way to do it, as MFP gives you maintenance for the day, not BMR for the day, so maintenance cals are included in you allotment, and should be backed out of the HRM total for the duration of the exercise.
  • katy4399
    katy4399 Posts: 136 Member
    I burn roughly 1 calorie per minute (BMR) so when I exercise with my HRM and burn 300 calories in 30 minutes I subtract 30 from 300 and log 270 calories burned.


    Hope this helps :)
  • erickirb
    erickirb Posts: 12,294 Member
    I burn roughly 1 calorie per minute (BMR) so when I exercise with my HRM and burn 300 calories in 30 minutes I subtract 30 from 300 and log 270 calories burned.


    Hope this helps :)

    which means your maintenance would be about 1.25cals/minute so doing that you would still be double counting the 0.25/min for the duration of exercise. This isn't a big difference unless you were say hiking or skiing for hours on end.
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