Big Difference Between Calculator and HRM

Hi All,

I just wanted to ask the community a few questions that maybe you can assist me with.

First of all, how does BMR work? I went to a weight loss doctor who gave me a breathing test and determined that my BMR was 2600. MFP set it at 2650, so it's close. I looked at some paperwork from two years ago when I was roughly 18 pounds lighter and this paperwork I got from another weight loss doctor says that it was 1591. That seems like quite a big of difference. Does this sound right?

Secondly, in my first week of trying to be good about eating and exercising, I lost one pound. I was slightly discouraged, but I decided to modify a few things to see if that helped. The second week, I adjusted my calories burned for exercise because I felt they were being too generous. Where the calculators were saying that I should be burning nearly 700-1000 calories, I would only log in 500 calories. Sure enough, this week I lost 3.5 pounds.

I purchased a Polar FT7 at the recommendation of a few people on here and I was blown away today when I wore it for the first time and it said I only burned 420 calories. I was dripping in sweat, giving it my all and WOW 420 calories?!?!

I am 273 lbs and have been going to the gym at least 2 days a week for 10 years, but only in the last year or so have I been doing 5-6 days. Only in the last two weeks have I really monitored my diet. Is it possible to be my size and be fitter than the average 273 lb woman? My doctor says according to his fit machine I have more muscle mass than most women at this weight. I'm just confused. I thought the bigger you were, the more calories you burn.

Any suggestions or comment are greatly appreciated.

Thank you!

Replies

  • jiggy66
    jiggy66 Posts: 52 Member
    PS: I'm afraid this means I am going to have to RUN instead my enjoyable cardio workouts :(
  • DanaDark
    DanaDark Posts: 2,187 Member
    BMR is the number of calories you need to fuel your organs.

    A BMR of 2600 is... huge. =/ I could imagine a TDEE that high, but a BMR... just wow.. maybe it's because I am a short/small guy.

    Thing is with estimated calorie burned, you can never really be sure. I usually recommend that people eat only half the calories back, to offset the uncertainty of them.

    Overall, you gotta find what is working for you that you can maintain and keep up. It is best to try and not to lose too fast as that can cause a stall later on and really discourage you.
  • jiggy66
    jiggy66 Posts: 52 Member
    Thank you for the reply! I thought the 2600 was awfully high when I looked back at my paperwork and saw that it was over a thousand calories different than my BMR was listed at in 2011. If I do an online BMR calculator online it says 2,000 and the funky formula 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years ) is roughly 1997. Maybe I should set my BMR as that. I am not sure what the TDEE is, but I will look that up.



    BMR is the number of calories you need to fuel your organs.

    A BMR of 2600 is... huge. =/ I could imagine a TDEE that high, but a BMR... just wow.. maybe it's because I am a short/small guy.

    Thing is with estimated calorie burned, you can never really be sure. I usually recommend that people eat only half the calories back, to offset the uncertainty of them.

    Overall, you gotta find what is working for you that you can maintain and keep up. It is best to try and not to lose too fast as that can cause a stall later on and really discourage you.
  • Canderson58054
    Canderson58054 Posts: 132 Member
    Hi All,

    I just wanted to ask the community a few questions that maybe you can assist me with.

    First of all, how does BMR work? I went to a weight loss doctor who gave me a breathing test and determined that my BMR was 2600. MFP set it at 2650, so it's close. I looked at some paperwork from two years ago when I was roughly 18 pounds lighter and this paperwork I got from another weight loss doctor says that it was 1591. That seems like quite a big of difference. Does this sound right?

    Secondly, in my first week of trying to be good about eating and exercising, I lost one pound. I was slightly discouraged, but I decided to modify a few things to see if that helped. The second week, I adjusted my calories burned for exercise because I felt they were being too generous. Where the calculators were saying that I should be burning nearly 700-1000 calories, I would only log in 500 calories. Sure enough, this week I lost 3.5 pounds.

    I purchased a Polar FT7 at the recommendation of a few people on here and I was blown away today when I wore it for the first time and it said I only burned 420 calories. I was dripping in sweat, giving it my all and WOW 420 calories?!?!

    I am 273 lbs and have been going to the gym at least 2 days a week for 10 years, but only in the last year or so have I been doing 5-6 days. Only in the last two weeks have I really monitored my diet. Is it possible to be my size and be fitter than the average 273 lb woman? My doctor says according to his fit machine I have more muscle mass than most women at this weight. I'm just confused. I thought the bigger you were, the more calories you burn.

    Any suggestions or comment are greatly appreciated.

    Thank you!

    I don't know what your height is- but I am not far off from your size. I am 6'1". MFP game me a BMR of around 2100 and using http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12?page=3
    This is the thread I used to adjust my macros. when i used the websites in the thread. it game me a BMR of 2080. ( harris benedict formula in Fat 2 Fit website) and BMR of 1882 when using my BF % into account( Katch-McArdle Forumla) . My TDEE is 2500-2860, depending if I pick sedentary or Light Active for an activity. So to me what you have as you BMR does sound like a TDEE. I would try reading and using the above thread I posted. Its helped out many people :)
    A few things about the excercise calcs... MFP calcs are way high. what the machine at the gym tells me i burned... is close to half of what MFP says. So I rarely used the MFP calcs. If I do- i usually cut it in half.I never eat all my excercise calories back either. If I burn 500 lets say- i might eat 200 calories back.... If I'm truly hungry, and most of the time its a fruit protein smoothie...lol. Bigger people do burn more calories.... play around on the calculators. Figure out what it would be for your weight.... and then figure out would it would be if you were 50 lbs lighter. Hang in there and just remember that even if you don't burn a huge amount of calories, excercise boosts your metabolism so when your done working out you are burning more then if you had never went. Good luck you :)
  • jiggy66
    jiggy66 Posts: 52 Member
    Thank you! I think I will adjust my calories and see what happens. I think you guys may be right that 2600 is my TDEE. I hope so at least. This can be confusing. I think I may be over thinking it, but I want to be successful, you know what I mean?

    Thanks again.
    Hi All,

    I just wanted to ask the community a few questions that maybe you can assist me with.

    First of all, how does BMR work? I went to a weight loss doctor who gave me a breathing test and determined that my BMR was 2600. MFP set it at 2650, so it's close. I looked at some paperwork from two years ago when I was roughly 18 pounds lighter and this paperwork I got from another weight loss doctor says that it was 1591. That seems like quite a big of difference. Does this sound right?

    Secondly, in my first week of trying to be good about eating and exercising, I lost one pound. I was slightly discouraged, but I decided to modify a few things to see if that helped. The second week, I adjusted my calories burned for exercise because I felt they were being too generous. Where the calculators were saying that I should be burning nearly 700-1000 calories, I would only log in 500 calories. Sure enough, this week I lost 3.5 pounds.

    I purchased a Polar FT7 at the recommendation of a few people on here and I was blown away today when I wore it for the first time and it said I only burned 420 calories. I was dripping in sweat, giving it my all and WOW 420 calories?!?!

    I am 273 lbs and have been going to the gym at least 2 days a week for 10 years, but only in the last year or so have I been doing 5-6 days. Only in the last two weeks have I really monitored my diet. Is it possible to be my size and be fitter than the average 273 lb woman? My doctor says according to his fit machine I have more muscle mass than most women at this weight. I'm just confused. I thought the bigger you were, the more calories you burn.

    Any suggestions or comment are greatly appreciated.

    Thank you!

    I don't know what your height is- but I am not far off from your size. I am 6'1". MFP game me a BMR of around 2100 and using http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12?page=3
    This is the thread I used to adjust my macros. when i used the websites in the thread. it game me a BMR of 2080. ( harris benedict formula in Fat 2 Fit website) and BMR of 1882 when using my BF % into account( Katch-McArdle Forumla) . My TDEE is 2500-2860, depending if I pick sedentary or Light Active for an activity. So to me what you have as you BMR does sound like a TDEE. I would try reading and using the above thread I posted. Its helped out many people :)
    A few things about the excercise calcs... MFP calcs are way high. what the machine at the gym tells me i burned... is close to half of what MFP says. So I rarely used the MFP calcs. If I do- i usually cut it in half.I never eat all my excercise calories back either. If I burn 500 lets say- i might eat 200 calories back.... If I'm truly hungry, and most of the time its a fruit protein smoothie...lol. Bigger people do burn more calories.... play around on the calculators. Figure out what it would be for your weight.... and then figure out would it would be if you were 50 lbs lighter. Hang in there and just remember that even if you don't burn a huge amount of calories, excercise boosts your metabolism so when your done working out you are burning more then if you had never went. Good luck you :)
  • firedupfriend
    firedupfriend Posts: 140 Member
    I have the FT4 and I had the same problem. I even had my HRM tested at an approved dealer which was faultless.
    The problem was that my chest strap was too loose.
    You should only be able to fit 2 fingers between your chest and the strap which is quite uncomfortable.
    SInce I have done this, my reading are better and aligned with computerised machines using the same measurements.
  • It's definitely possible that you're fitter and stronger than other women of your size but that won't change how many calories you burn to shift that weight. As you loose weight you'll find that you need to burn less calories as you're shifting less weight when you do things (I doubt if this will make much difference to your BMR but will massivly change your TDEE).

    With exercise I use a heartrate monitor when I cycle but from what I've read it will over calculate what I burn when my heart rate is high and under calculate when my heart rate is low. It also doesn't take into account how fit you are or what you'd have burned sitting on the sofa doing nothing. What proportion of the calories it tells you that you've burned largely depends on the type of exercise you're doing (and how many calories you've burned) as well as how often you exercise. If you're doing mammoth sessions each day and burning 2000 calories in two hours then if you only log 50% of what it says you've done and only eat back 50% of that the chances are you're going to be unable to exercise by day three because your body can't cope. If you're doing that session once a week and some light exercise the rest of the week then you could maybe get away with only logging 500 calories. It also depends on how strict your diet is, if you're aiming at half a pound a week weight loss then not eating back 800 calories of exercise is very different than if you're trying to loose two pound a week and only taking in 1200 calories a day.

    For me I cycle off between 1200 and 1400 calories 4-5 days a week and am fairly confident that my HRM is giving me a decent figure to base that on. I eat back all but about 100 calories of that and my weight loss has been great. If I didn't eat back most of those calories I found that on one of the climbs about six miles into the ride I ran out of energy and really struggled.
  • scottb81
    scottb81 Posts: 2,538 Member
    Fitness and weight are not directly correlated. It is possible to be fit and overweight at the same time. Since you have been regularly working out for a while it makes sense that your fitness is higher than average. The good news is that this will enable you to kick it up a notch quickly and do high quality workouts and with the right diet adjustments lose the weight you want to lose.
  • melaniecheeks
    melaniecheeks Posts: 6,349 Member
    1. You are losing weight, so you're doing something right!
    2. Do the workout that you enjoy and will stick to.
  • jiggy66
    jiggy66 Posts: 52 Member
    Thank you all for the replies. I suppose the simplest, yet best advice would be to keep doing what works and doing what I enjoy! It's interesting what Uncle points out about how the HRM will over calculate if HR is too high but underestimate if HF is too low. Go figure, huh? :-)
  • mztaylor83
    mztaylor83 Posts: 7 Member
    go to this site and it has a good definition of BMR and how to calculate it, effects weightloss etc. its got other good info too

    http://www.exercise4weightloss.com/basal-metabolic-rate.html