Setup Polar HRM for more accurate calorie burn for known BMR

TXHunny84

QUESTIONS!!::

Ok I have questions on your calorie burns and HRM numbers......I've often thought my HRM cal burns were off and were over estimated. Especially when I am just walking or jogging. My HRM would say a 3mph walk was like 550 cal burn in 60 minutes and MFP would say like 220 cals for a 3mph walk for 60 minutes. Way different numbers right!?.... Your info caught my attention so I plugged in all my info and it said my covert BF% was 22.2% and my new age was 13!!! Well that's a compliment I would LOVE to keep! BUT....first off....I have biggest loser scale and it says my BF% is actually 28.6%..... and so since I want to be accurate I put in that number too just to see what I would get and my BMR dropped....from 1593(as a 13yr old) to 1492(The day Columbus sailed the ocean blue) lol. So.....to get my age to match 1492 I had to change it to 34.5 years old.....
So should I set my HRM so think I am 13 or 34?

Plus: I have a fast resting heart rate at 90 bpm........if I input that I am older/younger won't that throw my results off more?.... I already felt that my calorie burns were over estimated due to my fast resting heart rate.

Plus: I have a slow thyroid....

*Plus:... I have been netting my calories at 1350 for the last few months..... I recently was going to change my cal goal to 1200 because I wasn't losing much weight.... According to what you said I'd have to put in my HRM that I am 95.....and well my HRM won't let me go that far back.....SAD TRUTH hahaha and because of my already fast resting heart rate wont that make it seem like I (as great-grandma) have some sky rocketing calorie burns!?....

Thank you for helping! This has been so interesting and I had made other posts before on the accuracy or lack of accuracy on my Polar FT4 and never could get an answer other than... "are you wearing it right? do you wash it daily? do you have it set to you info?" So thank you for posting this info sorry I have so many questions....

First, walking is great for using calorie calculator, because treadmill walking (running too actually) is most tested activity.
So use this site and see what it says. Better than MFP, which is based on same database many sites use.
http://www.exrx.net/Calculators/WalkRunMETs.html

Regarding BMR estimate based on BF%, I'd say avg those two. Scale is going to be around 6% accuracy if you are doing everything best it should be done (hydration, time, ect) and that is rare, and calc is 5% - so they do overlap actually.

I'd use that age, which is somewhere in-between - which is great, means you have better LBM than expected for your age/height/weight.

The HRM doesn't use resting HR in calc's, and besides, it's the maxHR that matters more than RHR. And indeed in your case, your MHR may be more than HRM is calculating (220-age).

So say for instance, you walked that 3mph, and HR was as 160 avg, and your MHR really was 175, that means that is a great effort for you. But if your MHR was really 200, not nearly as much.

If that 160 is hit because of being out of shape, as opposed to really just pushing it hard, difference too.

So as the first post mentions, MHR is bigger factor and should be tested too.

Might see what changes if you use height in this spreadsheet. HRM tab.

https://docs.google.com/spreadsheet/ccc?key=0Amt7QBR9-c6MdGVTbGswLUUzUHNVVUlNSW9wZWloeUE

Slow thyroid could effect things, but that does sound like a high cal burn estimate.

What does the other site calc say for your stats doing 3mph? And what was your AHR for that 3mph effort? And what incline? 20% sounds about right actually.

Yes I think my HRM is calculating my MHR too low because of my RHR already being fast. That's why I think ,y calorie burns are off. I'm worried if I change my age to being younger so my heart rate doesn't seem so high it'll make my calorie burns higher too and not accurate....and if I make my HRM think I am older that my heart rate is sky rocketing and giving me incorrect calorie burns. Thanks for helping. LOL I'm just odd I guess

heybales

Yes I think my HRM is calculating my MHR too low because of my RHR already being fast. That's why I think ,y calorie burns are off. I'm worried if I change my age to being younger so my heart rate doesn't seem so high it'll make my calorie burns higher too and not accurate....and if I make my HRM think I am older that my heart rate is sky rocketing and giving me incorrect calorie burns. Thanks for helping. LOL I'm just odd I guess

So you can test out what happens to age and calorie burn without touching your HRM.
Here is the formula from a Polar study, and likely the foundation of what they use in their HRM.

http://www.braydenwm.com/calburn.htm

graelwyn

Can someone check I got this right ?

age 37
height - 70 inches (think thats right for 5'10)
weight - 126 Ibs
bodyfat % - 19%

I got to reduce my age to 33... not much of a drop really for someone with 19% bodyfat.

heybales

Can someone check I got this right ?

age 37
height - 70 inches (think thats right for 5'10)
weight - 126 Ibs
bodyfat % - 19%

I got to reduce my age to 33... not much of a drop really for someone with 19% bodyfat.

BMR by age/weight/height is 1358.
BMR by weight/bodyfat% is 1370.

So you have about avg ratio of bodyfat/LBM as expected (tad better) - not much of a change for you to be worth messing with, unless you just feel like it. You could also keep the age, and increase your height to 73 inches in HRM for the same correction.

But, you are the age where the 220-age estimate for maxHR starts falling apart, because it's been found as you get older, you don't really lose a bpm per year, if at all. I'm still 17 higher than that formula would give.

So you'd benefit much more from second part of OP about estimating your maxHR better, and correcting the HRM stat on that.

graelwyn

Can someone check I got this right ?

age 37
height - 70 inches (think thats right for 5'10)
weight - 126 Ibs
bodyfat % - 19%

I got to reduce my age to 33... not much of a drop really for someone with 19% bodyfat.

BMR by age/weight/height is 1358.
BMR by weight/bodyfat% is 1370.

So you have about avg ratio of bodyfat/LBM as expected (tad better) - not much of a change for you to be worth messing with, unless you just feel like it. You could also keep the age, and increase your height to 73 inches in HRM for the same correction.

But, you are the age where the 220-age estimate for maxHR starts falling apart, because it's been found as you get older, you don't really lose a bpm per year, if at all. I'm still 17 higher than that formula would give.

So you'd benefit much more from second part of OP about estimating your maxHR better, and correcting the HRM stat on that.

Will look into that.

The trainer at my gym said 19% is good for a female, but looking at some of the drastic changes for peoples' bmr here, I am wondering if I should aim to get it lower. I am guessing that is the only real way to raise the bmr.

coachtruder

Bump

heybales

The trainer at my gym said 19% is good for a female, but looking at some of the drastic changes for peoples' bmr here, I am wondering if I should aim to get it lower. I am guessing that is the only real way to raise the bmr.

Uh oh, not going to like this. Because the biggest way to increase your BMR/RMR, outside always being cold, is have more muscle for the metabolism to take care of.

It's actually not by bodyfat%, but rather that and weight gives your Lean Body Mass, and LBM is actually what the calc's are based on.

So to increase your LBM with already excellent bodyfat% - gotta gain weight - muscle specifically.
Lifting rather than cardio.

But if you love the cardio more and already at goal weight, you may not want to carry around much more muscle than needed for your desired cardio activity.
Then again, if just for enjoyment, more muscle not a bad thing to have.

JaySpice

I think I bumped this...but I'm bumping again to read later.

reyopo

bump...until I've had some caffeine...

omma_to_3

So, if I adjust my age older than I really am, does that make my calorie burn go down for the same exercise? Just trying to figure that out before I go tinkering.

I know when I first tried this 2 months ago, I would have had to enter that I was like 84. This time I came up with 56 or 67 depending on which body fat estimate I use. Interesting...

jvheel

bump for later

heybales

So, if I adjust my age older than I really am, does that make my calorie burn go down for the same exercise? Just trying to figure that out before I go tinkering.

I know when I first tried this 2 months ago, I would have had to enter that I was like 84. This time I came up with 56 or 67 depending on which body fat estimate I use. Interesting...

Congrats, you lost mainly BF and kept your LBM.

Older metabolism is worse, slower, less calorie burn.

And just so on the same page, this doesn't make your calorie burn go up or down, it is allowing the HRM to more accurately report the fact that you already burn less than what you think.

So currently, you are getting inflated views of your calorie burn, and you aren't likely at that level. Same as mis-adjusted speedometer cable giving false speed reading. Really doesn't matter what your guage says incorrectly, it matters what the radar gun sees.

TXHunny84

thank you! this is an awesome post!

omma_to_3

So, if I adjust my age older than I really am, does that make my calorie burn go down for the same exercise? Just trying to figure that out before I go tinkering.

I know when I first tried this 2 months ago, I would have had to enter that I was like 84. This time I came up with 56 or 67 depending on which body fat estimate I use. Interesting...

Congrats, you lost mainly BF and kept your LBM.

Older metabolism is worse, slower, less calorie burn.

And just so on the same page, this doesn't make your calorie burn go up or down, it is allowing the HRM to more accurately report the fact that you already burn less than what you think.

So currently, you are getting inflated views of your calorie burn, and you aren't likely at that level. Same as mis-adjusted speedometer cable giving false speed reading. Really doesn't matter what your guage says incorrectly, it matters what the radar gun sees.

Well yes, obviously what my HRM says doesn't affect actual calorie burn. But I'm not sure that the calorie burn reported would go down. Isn't calorie burn based on your HR compared to your max HR (along with height and weight - should age only affect your BMR?). If I make myself older, my supposed max HR would be considerably lower so my workouts would far exceed the max HR.

omma_to_3

According to this website, a 56 yr old would burn 478 calories in 60 minutes of activity with an avg hr of 135. A same sized 37 year old would burn 457. So making myself older would burn more calories, according to the HRM.

http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

heybales

According to this website, a 56 yr old would burn 478 calories in 60 minutes of activity with an avg hr of 135. A same sized 37 year old would burn 457. So making myself older would burn more calories, according to the HRM.

http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

You are correct about the maxHR aspect in other post, and while a HRM does math of 220-age for maxHR, that may have no bearing on fact.

But true on that calc and formula, which does not have maxHR is part of calculator, but that comes across when the VO2max is calculated. Older would have worse VO2max.

But, you can see how close it is anyway.

kid75

Bump

stevo822

I have followed this so far through out the entire thread.

Question:

Using the change of BMR as per OP lowers mine from around 1850 (this is what I have been eating) to 1785. This makes my age around 42 ( I am 33)

Although my MHR hit 189 (which was monitored going up and back down) today so plus the 5 making 194 (the theoritical age of a 26 year old based on 220-age equation).

On my Polar FT4 I have the ability to adjust age and MHR individually, should I be changing both or just one of these?

Thank you .

heybales

I have followed this so far through out the entire thread.

Question:

Using the change of BMR as per OP lowers mine from around 1850 (this is what I have been eating) to 1785. This makes my age around 42 ( I am 33)

Although my MHR hit 189 (which was monitored going up and back down) today so plus the 5 making 194 (the theoritical age of a 26 year old based on 220-age equation).

On my Polar FT4 I have the ability to adjust age and MHR individually, should I be changing both or just one of these?

Thank you .

Most correction will come from adjusting that maxHR stat.

You can also adjust the height so the HRM knows about the same BMR that is more accurately calculated by BF%.

Use the spreadsheet referenced in this topic, the HRM tab, at the top. Still do the maxHR as lower down shows to do.

http://www.myfitnesspal.com/topics/show/620206-spreadsheet-for-bmr-tdee-deficit-calcs-mfp-tweaks-hrm

stevo822

I will check out that sheet when I can get access to it. Thank you.

Are you suggesting then to lower my height instead of age to allow for the slightly lower BMR? as well as the MHR.

Quick questions on the side of the first:

When entering the amount of cals burned during a workout onto MFP should I be deducting the amount of cals from the workout I would have normally burnt by sitting still?

eg: Workout 1 hour burn of 1000 cals. - the 100 cals I would have burnt by sitting still = 900 cals?

Also when measuring waist should you tense abs prior to measurements?