Setup Polar HRM for more accurate calorie burn for known BMR
Replies
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ok, so now that i had a chance to read through (most) of the post, i am wondering where this info is coming from. I tried to do some research online on this topic but the only hit i get is for this thread. So can you please tell me where the information regarding what polar uses to estimate calorie burn was found or where those other forums with people discussing this subject are? I would really like to read more about it....thanks!
btw i adjusted my height not weight...is that ok, does it work the same either way?
It's been so long ago digging around on this those original people researching are long gone, and since further research and testing on my own and with several on friends list that have different Polar's, it's not BMR, it's BMI, that is used to calculate VO2max. From that and HRmax is the calorie burn estimate.
I just don't have down what formula exactly they are using, or they may have tweaked one, but very close by about 50 calories over for avg effort for 1 hr. And that was tweaking the height to hopefully have it assume a known VO2max figure that was actually used on another nicer Polar that actually has that stat.
I don't fully understand. I have a polar Ft40 which has the vo2max test feature on it.
so was i supposed to mess around with my user info like it did or should i just leave it alone?
Leave it alone.
You'll benefit the most by confirming you get a really good self-test after you change your weight. Polar FAQ says morning after rest day, first thing, calm.
And then trying to figure out a best estimate for HRmax will help greatly too.
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max
Forget this method then, you got better HRM.0 -
so confused
I know my BF (just recently measured via calipers and hydrostatic - came in at 21%), and did the calculator thingy to figure out by BMR like I was supposed to and figured out that I am supposed to be 25yrs old vs my actual 31. so now, I should keep my weight the same (139), height the same (5'6) but change my birthdate on my polar FT7 to make me 25?
and then if i do this, I will get a more accurate reading of calories burned?
anyone know if being younger will show I am burning more calories because that would be awesome!!!!
It would, but the amount for that much is negligible.
It's bigger deal when you are 25, lost muscle mass, eat way to little, and so have the metabolism of a 60 yr old. That makes a difference.
Congrats on having BF% of 25 yr old your age, height, weight though - that's still good news and higher metabolism potential anyway.0 -
This is fascinating. According to your first post, I should be at age 23 instead of my 46 (when I was a kid, I never pretended to be older than 26, lol. I need to read through the rest and make sure I understand. Sounds really neat though! Thank you!0
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Thank you everyone for the information. Bump for later.0
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:huh:Everyone probably has noticed that when you setup your Polar HRM, you enter in gender, age (birthdate), weight, and height (sound like familiar stats?). You probably can change max HR also, perhaps VO2max on more expensive models.
So why use most correct stats as possible? Especially for women, your accuracy is all over the place for calorie burn. And calorie burn was probably the only reason you got the HRM, so why not have it as accurate as possible?
http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study
So Polar uses a BMR calc of stats as part of calculations for calorie burn.
So correcting any of those stats can improve what Polar estimates as your calorie burn. Because so many rely on that calorie estimate to tell them how many calories to eat back (very smart), more accuracy would probably be of benefit.
Which means if your estimated BMR based on body composition (Katch-McArdle formula) is different, or based on suppressed metabolism because of underfeeding it (NETting below BMR constantly), you could have a better estimate of calorie burn possible.
So probably the easiest method that doesn't require any self tests, would be adjusting your stats so Polar estimates with the same BMR you know is more accurate.
How to do it for body composition (Katch-McArdle BMR formula):
1 - Use the stats you entered into Polar (only sex, age, weight, height) here - http://www.gymgoal.com/dtool_bmr.html
________Note that BMR figure(that will not match MFP, which uses a slightly more accurate formula by Mifflin).
2 - Now get a decent estimate of your bodyfat% here - http://www.gymgoal.com/dtool_fat.html
________Use the Covert Bailey as accurate enough, and note it.
3 - Now take the BF% figure back to site in step 1 and use the optional % Body Fat stat.
________Note this more accurate estimate of your BMR based on your current Lean Body Mass (you are hoping this changes).
4 - Now remove the BF% stat, and adjust the age stat so the displayed BMR matches the estimate for BF% BMR.
________So that is the age of avg person with your BMR by Harris formula. That is what you enter into your Polar. When you drop 10 lbs, recalc your BF% and redo BMR calc based on it, to see if any need to change, hopefully you get younger biologically!
How to do it if your current daily goal has you NETting below your BMR on constant basis (per choice to lose weight slower):
1 - Get a decent estimate of what your BMR could be if fed (only sex, age, weight, height) - http://www.gymgoal.com/dtool_bmr.html
________This is not your true estimated BMR if netting below it for long enough to not be hungry anymore.
2 - Change the weight stat until the displayed BMR matches what you currently NET on constant basis (1200, 800, whatever).
________So that is the weight of avg person with your BMR running at full steam. That is what you enter into your Polar. When you drop 10 lbs or notice you are not netting so bad, recalc your BMR with what you are now netting constantly, or if you raise net goal at some point, hopefully you get heavier! Why not use age? You'd likely have to be 100 yrs old with metabolism that slow, but you can try it. Or change a little of both weight and age to show same slower BMR.
So the other reason for variance in the stats, is the MHR, and VO2max. Women again have big variance in true MHR, and resulting VO2max estimated from that.
And with the change to biological age above compared to chronological age, you may desire to adjust the MHR so the zones are correct, if that matters to you.
If you wish to get these as accurate as possible, here is a nice test to do if you have been exercising for a little while. With link if you are very aerobically fit for more serious test.
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max
If you have not been exercising that long, submaximal step test for MHR estimate.
http://doctorholmes.wordpress.com/2008/11/20/determine-your-maximum-heart-rate-with-the-step-test/
And for submaximal step test for VO2max, just use HRM for top bpm at end of test.
http://www.brianmac.co.uk/stepvo2max.htm
So hopefully by getting your more biological age down for both BMR and MHR compared to chronological age based on calculations, you can have better HRM calorie burn estimates, and hopefully you are eating those back to feed your workout so your body can improve and continue to give you great performance.
Oh, how did I come up with Polar is using BMR calc in their calorie estimates? Several online forums discussing. Tests people (and myself) did changing the values, doing exact same workout level for HR, and seeing the variance in estimate matches the variance in BMR changes.
Why could BMR calcs be that different? Because the BMR calcs are based on studies of people ALREADY at healthy weight, with avg LBM / BF ratios. If you have higher BF% at overweight compared to study partipants, then BMR is overestimated. At least with Katch BMR formula using LBM, while it was based on healthy weight subjects too, it will slightly underestimate at overweight, not as bad a deviation though.0 -
ok, so now that i had a chance to read through (most) of the post, i am wondering where this info is coming from. I tried to do some research online on this topic but the only hit i get is for this thread. So can you please tell me where the information regarding what polar uses to estimate calorie burn was found or where those other forums with people discussing this subject are? I would really like to read more about it....thanks!
btw i adjusted my height not weight...is that ok, does it work the same either way?
It's been so long ago digging around on this those original people researching are long gone, and since further research and testing on my own and with several on friends list that have different Polar's, it's not BMR, it's BMI, that is used to calculate VO2max. From that and HRmax is the calorie burn estimate.
I just don't have down what formula exactly they are using, or they may have tweaked one, but very close by about 50 calories over for avg effort for 1 hr. And that was tweaking the height to hopefully have it assume a known VO2max figure that was actually used on another nicer Polar that actually has that stat.
I don't fully understand. I have a polar Ft40 which has the vo2max test feature on it.
so was i supposed to mess around with my user info like it did or should i just leave it alone?
Leave it alone.
You'll benefit the most by confirming you get a really good self-test after you change your weight. Polar FAQ says morning after rest day, first thing, calm.
And then trying to figure out a best estimate for HRmax will help greatly too.
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max
Forget this method then, you got better HRM.
ok, thank you for clearing that up for me
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I love your post about accurate calculations for my Polar but got a bit confused. I'm hoping you can help.
I have been using MFP to help me lose weight. I'm 48, male, 6' and follow the MFP calculations of 1200 calories per day for a 2lbs per week loss. Currently at 177lbs and not too much further to go.
I workout with my Polar and have been subtracting 100 calories per hour (just a guess!) to compensate for BMR then eating the extra calories burned - roughly 750 per day. I'm fastidious about entering my food eaten on MFP along with calories burned but sometimes I lose weight and sometimes it plateaus so I'm after greater accuracy.
My VO2 is 58 (calculated with the step test but also tallies with the Polar fit test).
As it's all been guess work I was thrilled to find your post. Using your calculator links my fat % is 14.7% which when put into the first calculator gives me a BMR of 1852 which works out at age 35.
Fantastic I thought and was about to change my Polar then I read the second part of your post and got horribly confused!!
I have no idea what netting is and netting lower for slower calorie loss. Or indeed if that's what's happening when I don't lose weight.
I'm not sure if my net is what MFP says (the 1200 figure) or what it should be for no calorie loss....or is it a figure with exercise? or without it? Or indeed if I should worry about it at all!
Am I OK to just change the age in my Polar settings to continue with the weight loss by getting an accurate calorie expenditure readout or do I need to adjust anything else?
Do I keep my age on MFP settings at 48 or do I change that to 35 too?
Also ....I'm sorry if there are too many questions here but you seem to have knowledge nobody else does!- is the BMR figure of 1852 the amount I should eat to keep a stable weight ( if say I wanted to keep at 177 lbs).
Hoping this is all clear!!
Best wishes and hanks for shedding light!
Ben0 -
I love your post about accurate calculations for my Polar but got a bit confused. I'm hoping you can help.
I have been using MFP to help me lose weight. I'm 48, male, 6' and follow the MFP calculations of 1200 calories per day for a 2lbs per week loss. Currently at 177lbs and not too much further to go.
I workout with my Polar and have been subtracting 100 calories per hour (just a guess!) to compensate for BMR then eating the extra calories burned - roughly 750 per day. I'm fastidious about entering my food eaten on MFP along with calories burned but sometimes I lose weight and sometimes it plateaus so I'm after greater accuracy.
My VO2 is 58 (calculated with the step test but also tallies with the Polar fit test).
As it's all been guess work I was thrilled to find your post. Using your calculator links my fat % is 14.7% which when put into the first calculator gives me a BMR of 1852 which works out at age 35.
Fantastic I thought and was about to change my Polar then I read the second part of your post and got horribly confused!!
I have no idea what netting is and netting lower for slower calorie loss. Or indeed if that's what's happening when I don't lose weight.
I'm not sure if my net is what MFP says (the 1200 figure) or what it should be for no calorie loss....or is it a figure with exercise? or without it? Or indeed if I should worry about it at all!
Am I OK to just change the age in my Polar settings to continue with the weight loss by getting an accurate calorie expenditure readout or do I need to adjust anything else?
Do I keep my age on MFP settings at 48 or do I change that to 35 too?
Also ....I'm sorry if there are too many questions here but you seem to have knowledge nobody else does!- is the BMR figure of 1852 the amount I should eat to keep a stable weight ( if say I wanted to keep at 177 lbs).
Hoping this is all clear!!
Best wishes and hanks for shedding light!
Ben
Yep, forget this method, you have better HRM with VO2max test and stat that keeps it better.
Though using that second part you get a decent peak at the metabolic age you are forcing on yourself.
1200 calories is correct BMR for a male your weight and height, and how old compared to your age?
Eating so little though, your concern is going to be how much has your body slowed down the metabolism in general to match the level of under-feeding it's getting.
Body would like to burn 1852 calories daily if sleeping deeply, by best estimate.
You are feeding it 1200, or possibly leaving it 1100 on workout days.
That's not going to have good results for long if ever.
Unless good results means to you purely weight loss, no matter what the weight really is. But I'm guessing with calorie burns that high, you wouldn't mind actually making good strong body improvements from the exercise.0 -
bump0
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heybales,
I recently purchased a polar ft7 and got some readings that seemed far fetched so googled and came up to this thread.
Today I walked 1 mile to the gym, then did a 5x5 workout with squats, over head presses, and deadlifts. The Squats were around 80% of my 1 rep max. The other two lower. Then, I walked 1 mile home from the gym.
The readings it gave me were:
2.75 hours for workout
Average: 118
Max: 155
Calories burned: 1240
Fat Burn: 1 hour 45 mins
Fitness: 45 mins
1240 calories burned seemed really high.
My stats:
Male
38 Years old
5' 9"
294lbs
I read your explanation on how to make it more accurate and came out with 2229 BMR and 35.6% BF. I then deleted bodyfat % and tried to figure out my age without it. It came out to 81.5! I put the age back to my regular age and tried it with height. My height would 45.5 inches which is almost 4 foot.
So, once I either input the modified age OR height I should get a more accurate reading, correct? Even if it turns out more accurate how much of a % do you think I should eat back to start with? Then I can slowly raise the % higher and see the effects on my weight loss and if it turns out too much then lower it again.0 -
heybales,
I recently purchased a polar ft7 and got some readings that seemed far fetched so googled and came up to this thread.
Today I walked 1 mile to the gym, then did a 5x5 workout with squats, over head presses, and deadlifts. The Squats were around 80% of my 1 rep max. The other two lower. Then, I walked 1 mile home from the gym.
The readings it gave me were:
2.75 hours for workout
Average: 118
Max: 155
Calories burned: 1240
Fat Burn: 1 hour 45 mins
Fitness: 45 mins
1240 calories burned seemed really high.
My stats:
Male
38 Years old
5' 9"
294lbs
I read your explanation on how to make it more accurate and came out with 2229 BMR and 35.6% BF. I then deleted bodyfat % and tried to figure out my age without it. It came out to 81.5! I put the age back to my regular age and tried it with height. My height would 45.5 inches which is almost 4 foot.
So, once I either input the modified age OR height I should get a more accurate reading, correct? Even if it turns out more accurate how much of a % do you think I should eat back to start with? Then I can slowly raise the % higher and see the effects on my weight loss and if it turns out too much then lower it again.
You are correct, that is inflated.
The formula that ties calorie burn to HR is only valid for exercise in the aerobic range that is steady-state, same HR for 2-4 min.
Lifting is neither aerobic nor steady-state - so very inflated.
Your walking would be good, but the cheaper Polars assume an important stat of VO2max is low if your BMI is high, which generally may be true, but could soon be very wrong and bad assumption, meaning you actually burn more than it's giving you credit for.
Forget this method as it won't correct enough.
But with default settings, you can test how close it is.
http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is
And actually, if you had reached those HR readings with cardio exercise - that is very realistic calorie burn.
If doing the MFP method of exercise eat-back correctly, take 10% off, that's basically what you were going to burn anyway during that time, that way you are only logging and eat-back what is truly over and above what you already have accounted for.0 -
I did a major error and only did 10 minutes of warmup and 10 minutes of walking @ 120 bpm. The pace was 20 and was 2.3mph w/ a grade of zero. Anyway, my HRM calculated it at 90 calories and the website calculated it at 65 for a difference of 25 calories.
Wasn't sure on the Difference/Calculated = % error unless it was 25/65 which was a 2.6% error or 25/90 (HRM calculated) which is a 3.6% error.
So should I keep using that website in order to gauge the true calories burned while using the HRM to make sure I am 120 bpm+ when I do some cardio?0 -
I did a major error and only did 10 minutes of warmup and 10 minutes of walking @ 120 bpm. The pace was 20 and was 2.3mph w/ a grade of zero. Anyway, my HRM calculated it at 90 calories and the website calculated it at 65 for a difference of 25 calories.
Wasn't sure on the Difference/Calculated = % error unless it was 25/65 which was a 2.6% error or 25/90 (HRM calculated) which is a 3.6% error.
So should I keep using that website in order to gauge the true calories burned while using the HRM to make sure I am 120 bpm+ when I do some cardio?
Ah, so the HRM was the entire time, 10 + 10?
Or you started it on the 10 min test part only?
So your correction factor at 120 BPM would be 0.72.
So if you averaged 120 BPM for a workout, you could take the HRM calorie estimate x 0.72 and get better estimate of burn.
For treadmill, you might even see what it says sometimes if you enter in a weight. Those formula's have been around a while sence the treadmill is the most lab used cardio equipment for actually measuring calorie burn using much more precise methods.
I would use the website, because for purpose of eating back exercise calories, you can select NET instead of Gross, and NET is what you'd actually eat back. Gross, which MPF, HRM, treadmill all use, includes the calories you would have burned anyway. NET is just the calorie above what you would have burned resting.
I'd suggest right now you are out of shape, and you will see that change quickly if you keep it up.
I'd keep those stats in a log - weight, pace, incline, time, avgHR.
Because you will be very impressed when you find the pace going up so fast to keep that avgHR. But I'd make that a test day.
You should see what pace you need to have yourself talking in broken phrases because you are breathing enough. You don't want easy talking in full sentences, that's recovery level. You don't want unable to talk except single words, that's moving in to anaerobic level. Small phrases are fine, that's aerobic level. See what HR that is.
That's the HR you want the majority of your workouts to be right now for several weeks building up an aerobic base.
After a month, do another 120 BPM test to see what pace is needed now. And to see what the correction factor is to the HRM estimated calorie burn.
And then you can start throwing in some 30 sec to 1 min spans of unable to talk level. See what the HR is there. That's brief anaerobic intervals. Be aerobic for 3 x as long before you repeat.
And you can do that with whatever cardio you enjoy, same HR basically applies across whatever you are doing, except swimming.0 -
I am a little skeptical, according to this i need to make myself 79 on my polar, i am 34!! I used my scales to get my bf% which i assume is fine? Now my mhr says 134 and i am regularly around 170-174 doing hiit0
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Bump!0
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Bump for later, when my Polar returns from warranty repair.0
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Bump for later. Lot o' math. :bigsmile:0
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I am a little skeptical, according to this i need to make myself 79 on my polar, i am 34!! I used my scales to get my bf% which i assume is fine? Now my mhr says 134 and i am regularly around 170-174 doing hiit
This is more an attempt to notice that if you are under-eating for your level of activity, or have more fat than average, you are basically pushing your metabolic age older in order to try to tell the HRM you have a slower metabolism.
And scales for BF% can be within 5% accurate, if following manufacturer's recommendations for same hydration levels. But don't do that, and cheaper ones, can be 10% accurate.
Better is consistent, so you see a direction of movement at least.
You do have to change your HRmax though back to better estimated value.
Better is this method now to see how far off your current HRM and settings are.
http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is0
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