POLAR HRM vs MFP

lahlie

Ok. I need to clarification/reassurance/introspect into my measuring my calorie use during exercise. I have the Polar FT7 HRM, and it is set to my body. I went for a walk, pushing my twins in a stroller (80lbs between the two of them) for 3 miles....about 55 minutes. My HRM said I burned 626 calories. Now, MFP, shows that just walking for that amount of time at a leisurely pace, that I only burned 302 calories. I know it doesnt take into account my pushing a stroller, but what should I log? I have always never thought twice about trusting my Polar HRM, but now, I am not so sure....

gemiwing

Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

tinana_RN

Log from your HRM. I push a stroller and use my HRM when I walk with the kids, I always take the HRM number over MFP.

erickirb

how high was your HR?

Le_Joy

I'd go with HRM over MFP, takes more of your personal info into account.

erickirb

Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.

harlanJEN

HRM. Is connected to YOU .. MFP isn't : )

mellabyte

HRM all the way. MFP, I think, are general baseline estimates.

heddylyn

HRM definitely. MFP is just an estimate based on the average person (which is usually considered 150 pounds). You'll burn more or less depending on your weight and actual heart rate.

htolen

I have the opposite problem; I don't have an HRM (yet!), but when I go to the gym and use the elliptical trainer, the machine will say that I burn about 660 calories for an hour-long workout. When I come home and log into MFP, if I plug in 60 minutes of elliptical training, MFP says I burn almost 900 calories. I always adjust the minutes that I enter on MFP to match the calories that the machine says I burned, because I think MFP numbers are very generalized and don't necessarily take into account the speed and intensity of my workouts whereas the machine at the gym does. I think. So I agree with what everyone else is saying: adjust the minutes or the intensity (instead of "slow pace," or "walking dog" pace, go for more intense walking) so that the MFP database logs what your HRM says you actually burned.

I can't wait to get one of those HRMs...they are so cool!

Good job on the exercising, too! :-)

SheehyCFC

Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.

His question about HR above will give a good indication... (what's your resting HR as well?). I would trust the HRM but not to a fault. Also realize that you need to subtract out your BMR calories from that... so if it was 1 hour of exercise, that is likely ~100 calories less you should be counting.

**EDIT for clarity

ashreynolds09

I have the exact same HRM and I always just override what MFP says and use what my HRM tells me. The HRM uses your heart rate to determine your calories burned. Your heart rate changes with your intensity levels. MFP just goes off of basic numbers...your current weight, age, and height --- (really, I have no idea I'm just assuming that it uses these) and what the average person with those stats would burn.

Hodar

Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

No HRM knows how hard you worked. It 'assumes' your rest heart-rate is 'x' and then uses a table to look up instantaneous heart-rates over the 'x' value to calculate a total caloric burn. This is like looking at how may RPM's your engine is running, and predicting how fast you are driving and what direction. You simply do not have enough data to make this prediction. Are you sitting in your driveway with a fast idle? Are you spinning on ice? Are you flying downhill?

My rest HR is 46 bpm, my wife has a rest HR of 88. I have to bust my butt to get it up to 108, my wife needs merely to walk across the street to get the mail. To say that our caloric burns are comparable based solely upon our HR is a bit of an exaggeration.

To get an accurate caloric reading, the HRM would need to know YOUR average rest heart rate, you rate of conversion of O2 to CO2, your weight, the distance you are travelling, the speed at which you are travelling (we tend to 'jump' when we run, vs a smooth transaction when we walk). the starting and ending elevations, your age, fitness and gender - and that's just off the top of my head. A marathon runner will burn far less calories in a 1.5 mile jog than I will, simply because his body is tuned to this sort of thing - while mine is not.

Everything we use is a 'best guess' - it's simply making due with lots of "Rules of Thumb".

gemiwing

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

JaySpice

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

OMG! Yes! I mean dang, It may be off a bit but not by 300+ calories.

lahlie

avg HR 182
Max HR 197

RHR usually in the high 70s low 80s

JaySpice

My rest HR is 46 bpm, my wife has a rest HR of 88. I have to bust my butt to get it up to 108, my wife needs merely to walk across the street to get the mail. To say that our caloric burns are comparable based solely upon our HR is a bit of an exaggeration.

But doesn't the HRM take your resting HR in consideration? When I set up my HRM I put in my height and weight and allathat so when I start a work out it's close to my resting HR (if I haven't been running around the house looking for the dang thing). So if your resting HR is 46 then the HRM should know how hard you are working to get your HR up to 108...right?

lahlie

Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.

His question about HR above will give a good indication... (what's your resting HR as well?). I would trust the HRM but not to a fault. Also realize that you need to subtract out your BMR calories from that... so if it was 1 hour of exercise, that is likely ~100 calories less you should be counting.

**EDIT for clarity

on this particular workout
avg HR 182
max HR 197

RHR usually in high 70s/low 80s

SheehyCFC

avg HR 182
Max HR 197
RHR usually in the high 70s low 80s

That is EXTREMELY high HR... how hard were you struggling? Have you done this before and gotten those readings? If you weren't gasping for air nearly the whole time, I think something may be off...

**EDIT - you just said you "walked" so I don't see how those numbers are possible. I would go by MFP in this case. Also, make sure the electrodes are properly positioned to get the most accurate reading possible

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

umm... in this case it could be that much considering she is seeing a HR that high (and it is more likely in the 140-150 range) for an entire HOUR

Meg_78

Polar wins hands down, MFP estimates so low for me, almost by half sometimes.

lahlie

avg HR 182
Max HR 197
RHR usually in the high 70s low 80s

That is EXTREMELY high HR... how hard were you struggling? Have you done this before and gotten those readings? If you weren't gasping for air nearly the whole time, I think something may be off...

**EDIT - you just said you "walked" so I don't see how those numbers are possible. I would go by MFP in this case. Also, make sure the electrodes are properly positioned to get the most accurate reading possible

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

umm... in this case it could be that much considering she is seeing a HR that high (and it is more likely in the 140-150 range) for an entire HOUR

No....I am in THAT bad of shape.... Yes, I was huffing and puffing pretty much the whole time.

JaySpice

No....I am in THAT bad of shape.... Yes, I was huffing and puffing pretty much the whole time.

Then most def count your what HRM said.

jordanp1227

HRM! it goes off of your personal info not what someone else put in

beaner1st

avg HR 182
Max HR 197
RHR usually in the high 70s low 80s

That is EXTREMELY high HR... how hard were you struggling? Have you done this before and gotten those readings? If you weren't gasping for air nearly the whole time, I think something may be off...

**EDIT - you just said you "walked" so I don't see how those numbers are possible. I would go by MFP in this case. Also, make sure the electrodes are properly positioned to get the most accurate reading possible

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

umm... in this case it could be that much considering she is seeing a HR that high (and it is more likely in the 140-150 range) for an entire HOUR

My heart rate can easily run in the 170s when working out and I have a resting heartrate in the 60s and am in pretty good shape and not struggling very much. When I have asked various "experts" I am told them same thing as long as it comes down quickly it is ok (which it does) and that I am lucky because I am burning more calories than many.

SheehyCFC

No....I am in THAT bad of shape.... Yes, I was huffing and puffing pretty much the whole time.

I wasn't trying to discourage you in anyway, sorry if it came off that way... it just seems like those numbers are off. your THEORETICAL (yeah, it required italics) max HR is 220 - your age... so getting to 197 would be over that... especially if you are doing it for extended period of time (average 182).

I'm not saying it isn't possible, but I am saying it seems unlikely. If you have gotten repeatable measurements (read: precision) at this level, then by all means use the HRM... otherwise use MFP. And as I said, you should be subtracting your BMR whenever you use a HRM... do you know what it is? That would swing the HRM down 100-200 calories, depending...

mellabyte

Your high HR is probably true to your assumption that you're feeling that out of shape.

When I first started working out, my resting heart rate was like high 80's to mid 90's. And I would always get up to 180 to almost 190 and not yet be at my max. I was told that unless I felt dizzy, faint or had chest pains, then this was just my being in terrible shape and my heart in general just not being strong due to lack of cardio workouts.

Now my resting heart rate is anywhere from the low 60's to mid 70's (sometimes even at mid 50's). And I only reach 180+ if I'm really effin' workin' it, which is usually pushing myself running (because I suck at it :P). During typical cardio workouts my HR usually doesn't get above 165-170 now.

I think the polar FT7's are supposed to take in your resting and then calculate from there. I've noticed that my ranges change for me. That some days, the cut-off mark from "fat burn effect" to "fitness effect" varies and is lower on some days and higher on others. -scratches head-

lahlie

No....I am in THAT bad of shape.... Yes, I was huffing and puffing pretty much the whole time.

I wasn't trying to discourage you in anyway, sorry if it came off that way... it just seems like those numbers are off. your THEORETICAL (yeah, it required italics) max HR is 220 - your age... so getting to 197 would be over that... especially if you are doing it for extended period of time (average 182).

I'm not saying it isn't possible, but I am saying it seems unlikely. If you have gotten repeatable measurements (read: precision) at this level, then by all means use the HRM... otherwise use MFP. And as I said, you should be subtracting your BMR whenever you use a HRM... do you know what it is? That would swing the HRM down 100-200 calories, depending...

Ok. So, to give a little comparison. Riding my bike for 34 minute I burned 365 cal. max HR: 192 Avg HR 172

SheehyCFC

Ok. So, to give a little comparison. Riding my bike for 34 minute I burned 365 cal. max HR: 192 Avg HR 172

That seems extremely likely/possible (calorie burn, exertion)... though 192 is high, it seems reasonable. So maybe the HRM is right. As mella said above, I may be accounting too much for being further along in the journey, and apologize if I seemed misleading. Go with the HRM, but make sure to back out your BMR cals. Best of luck

**EDIT - Was riding bike really equivalent to walking the kids in a stroller? If you think so, than the HRM was accurate

lahlie

Ok. So, to give a little comparison. Riding my bike for 34 minute I burned 365 cal. max HR: 192 Avg HR 172

That seems extremely likely/possible (calorie burn, exertion)... though 192 is high, it seems reasonable. So maybe the HRM is right. As mella said above, I may be accounting too much for being further along in the journey, and apologize if I seemed misleading. Go with the HRM, but make sure to back out your BMR cals.

Best of luck

Why do you subtract out the BMR calories?

Azdak

OK you pedantic people you-

How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

According to your workout heart rate info (that you listed in another comment), your HRM could be overestimating your calories by a significant amount, if you have it programmed with default values. Your age-predicted HR max is in the upper 180s which is your average workout heart rate. So the HRM assumes you are working at 100+% of your VO2max for 55 minutes. That's significant.

SheehyCFC

Why do you subtract out the BMR calories?

Most HRM do not take into account your calories burned at rest... they just account for the calories burned for a given duration at a given HR. In these cases, you would be "double counting" the calories burned from just living. I know for my polar A5, I have to back out ~90-100 calories (BMR) per hour. I'm not 100% sure on the FT7, but you can do a forum search and the answer should be there.