Using my HRM to accurately calculate BMR

CookieGem
CookieGem Posts: 197 Member
in Health and Weight Loss
Hello all,

So i am sick of not losing weight. I have a under-active thyroid and i think that impacts my weight loss but honestly i think its because I have no idea what my BMR is. I have used calculators online but between 10 different calculators theres a 500 cal difference (which is huge).

So first thing this morning i put on my HRM, been wearing it for nearly 6 hours and burnt 624 cals just to try get a more accurate result.

My question is as I am unsure. Do i wear it all day and night for a full 24 hours or do i take it off before i go to bed and take that reading?

Thanks guys.

Replies

  • mimieon
    mimieon Posts: 182 Member
    I would say also wear it at night. I'm wondering though if this calorie burn from the heart rate monitor will be accurate for all activities besides cardio exercise (?).
  • Richard269
    Richard269 Posts: 56
    Hi , for your HRM to give you a true reading you have to have your heart rate raised , so just by sitting around you will not get a true reading .
  • mimieon
    mimieon Posts: 182 Member
    Hi , for your HRM to give you a true reading you have to have your heart rate raised , so just by sitting around you will not get a true reading .

    Could you explain why?
  • kristen6022
    kristen6022 Posts: 1,923 Member
    It wouldn't give you a true reading. The only way it would work is if you laid around ALL day and ALL night and didn't move because your BMR is what you would burn if you were in coma. And then I don't think it would really provide accurate results because a HRM is the most accurate when you are in your target heart rate zone...
  • ThePolishExperiment
    ThePolishExperiment Posts: 32 Member
    Hi CookieGem, okay here's the long and the short of it. your BRM is calculated by your height, weight, age. If you want me to do it i can work it out for you, and work out the calorie goals, add me and i will explain more about why you might be getting confused. Because wearing a HRM won't give you an accurate BMR, thats not what they are designed for.
  • Richard269
    Richard269 Posts: 56
    Yer was going to wear one for 24 hrs when I 1st got mine . Had a look on some web sites and they all say the same that your heart rate has to be under load . It's the same when you lift weights
    Sorry could not be of more help
  • LittleMissDover
    LittleMissDover Posts: 820 Member
    Hi CookieGem, okay here's the long and the short of it. your BRM is calculated by your height, weight, age. If you want me to do it i can work it out for you, and work out the calorie goals, add me and i will explain more about why you might be getting confused. Because wearing a HRM won't give you an accurate BMR, thats not what they are designed for.

    That still doesn't give you your exact BMR, just a generic one, not every 5ft 2 female that weighs 120lbs (example) is going to have the same BMR.

    OP, I believe there are tests doctors can do to determine your true BMR but I have no idea how you'd go about getting one.

    For a start though you don't log consistently, until you have done for a decent period of time I don't think you can really see why you're not losing.
  • ThePolishExperiment
    ThePolishExperiment Posts: 32 Member
    it won't give you an exact BMR down to the final digit, but it gives you a good estimate, and if it didn't work, then I wouldn't have lost 20lbs using that method.
  • veobrien
    veobrien Posts: 39 Member
    You would definitely need to include some sleep time. If you don't wear it to bed, you'd end up using a calculator of some sort to estimate sleep calories (but they are the very things you're questioning!)

    I am interested in other's replies because I have thought of doing that in the past.... but I did conclude that, for my own knowledge, it wasn't worth it really. Since I don't physically doing the same things every day, I figured I was going to end up with a figure that is no less general than taking the average figure of all the online calculators, in my opinion. So, for me, I bought a fitbit and learned to trust that and it seems to have worked for me.

    Interested in your results though - please come back and let us know!
  • mich1902
    mich1902 Posts: 182
    I have wore my hrm once for 24 hours inc sleep. i did it on a day i wasn't exercising but just doing normal every day activities; however will this not give you cals burned close to your tdee rather than bmr? It actually worked out a couple hundred over my calculated tdee based on results from the scooby calcs. I know the results from the hrm will not be that accurate but I was just curious.
  • deniseblossoms
    deniseblossoms Posts: 373 Member
    it won't give you an exact BMR down to the final digit, but it gives you a good estimate, and if it didn't work, then I wouldn't have lost 20lbs using that method.

    It might not give you a good estimate if you fall outside of the "norm".
  • ThePolishExperiment
    ThePolishExperiment Posts: 32 Member
    i'm not 'the norm' and BMR isn't the most important thing to worry about when losing weight, it is one of the key factors, so that you know how much you need to be eating but if your exercising hard and not ramming sugar laiden, carb heavy, deep fried foods down your neck, getting plenty of fruit and veg, and protein, and limiting your carbs, the results will come with time and patience.
  • bwnorton
    bwnorton Posts: 100 Member
    You mentioned an under-active thyroid and haven't been able to lose weight when you dropped your calorie intake. If I were you, I would talk with a dietitian who works with people with thyroid difficulties. All of the public formulas assume a normal metabolism - and normal thyroid hormone levels. Because it's a medical issue, your insurance may cover part of the appointment.

    If you are very intent on knowing your BMR, they could send you to an indirect calorimetry laboratory. You lay down on a bed and they measure how much C02 you produce over a period of time.
  • CookieGem
    CookieGem Posts: 197 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.
  • kellehbeans
    kellehbeans Posts: 838 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.

    That's not true. You can go to a dietitian or see your nutritionist in your local medical centre. I started my journey by frequently visiting my nurse who was trained for this sort of stuff, and she helped me alter what I ate and gave me lots of helpful advice. And I've been to a dietitian on the NHS before.
  • LittleMissDover
    LittleMissDover Posts: 820 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.

    That's not true. You can go to a dietitian or see your nutritionist in your local medical centre. I started my journey by frequently visiting my nurse who was trained for this sort of stuff, and she helped me alter what I ate and gave me lots of helpful advice. And I've been to a dietitian on the NHS before.

    Depends on your doctor TBH, mine shrugged his shoulders when I said my weight loss had come to a standstill.
  • jaz050465
    jaz050465 Posts: 3,508 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.

    How can you POSSIBLY say health care in the USA is better than the UK. We get nearly everything for free. Have you asked to be referred to a dietician. If not you can contact a freelance one. Many work using email/ phone consultations.

    If its a health issue then the NHS will pay. If not, then a couple of sessions from a professional,will surely be worth it, if its important to you.
  • Melissa22G
    Melissa22G Posts: 847 Member
    You could also use a site to find your BMR:

    I suggest fat2fitradio.com.
  • myofibril
    myofibril Posts: 4,500 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.

    If you want to accurately know your RMR / BMR then you won't be able to do it with any kind of accuracy using a HRM - they are simply not designed for that purpose.

    However, you can get your RMR professionally tested using indirect calorimetry at some gyms / sports facilities etc. It is relatively cheap £75.00 - £100 or so.

    It might sound a lot but given the certainty it provides you it is far better value than any fitness gadget.
  • myofibril
    myofibril Posts: 4,500 Member
    http://www.drummondclinic.co.uk/service/rmr-assessment/

    You could check out those guys if you are interested.

    RMR tests are different from VO2 max / exercise tests which are more about athletic performance.
  • watfordjc
    watfordjc Posts: 304 Member
    Brad3k, you clearly live in america or somewhere where the health service is better. Here in the UK we don't have the luxury of seeing a dietitian unless we pay big money, which is such a shame as I thiknk that is prob what i need to do :)

    Thanks for the reply.

    How can you POSSIBLY say health care in the USA is better than the UK. We get nearly everything for free. Have you asked to be referred to a dietician. If not you can contact a freelance one. Many work using email/ phone consultations.

    If its a health issue then the NHS will pay. If not, then a couple of sessions from a professional,will surely be worth it, if its important to you.

    Free doesn't necessarily mean better. I've tried getting my Asperger's and circadian rhythm disorder diagnosed - "if you have it you can't be cured, finding out won't change anything, no point in a referral".
  • Querian
    Querian Posts: 419 Member
    I also like Fat2Fit radio but I recently got a FitBit and I really like the calorie recommendations it makes for me. I was on a 3-4 week plateau and since I got my FitBit I started losing again. It's only been 2 weeks but I did lose 3.2 pounds in that time and I've been eating around 1800-2100 calories a day in that time (range based on daily activity level). The FitBit also inspires me to be more active each day which I like because I like eating more!

    I am 5'4", currently 181 pounds and let's say my goal weight is 146 (maximum healthy BMI for my height). PS I am 40. I chose moderately active which is 3-5 hours of exercise a week. I used 36% for body fat since that is what my scale says.

    Scooby Workshop says my BMR is 1549, my TDEE is 2402 and TDEE - 20% is 1921

    Fat2Fit Radio says my BMR is between 1509 and 1555. They recommend I eat 2175 per day for the moderately active level.

    I think if I ate the 2175 I would still lose but maybe a it slower. All of these numbers are pretty similar, I'm not sure how you are getting a 500 calorie difference in your BMR. My range is only from 1509-1555 which is less than 50 calories.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    You will not get an accurate calculation of BMR this way, it will actually be overinflated. The HRM is not designed for that. HRM measure heart rate. Heart rate has no direct relationship to calories burned. The HRM bases its calorie estimation on a known relationship between VO2 max and calories burned during steady state moderate intensity cardio, when your heart rate is at a certain percentage of your VO2 max. There is a very low correlation to heart rate and calories burned during low intensity, which would be the majority of the day.
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn


    Also keep in mind that there are any number of factors that affect heart rate that have nothing to do with calories burned. The HRM assumes that any elevated heart rate is due to cardio exorcise and estimates calories based on that. It has no idea if you are running a 10 minute mile or if something just startled you.

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