Polar FT4: Accurate?!

maliciouspenguin
maliciouspenguin Posts: 37 Member
in Fitness and Exercise
So I'm wearing my FT4, with chest strap and everything. Seems to be registering my heart rate accurately (measured it in line with fingers on neck/wrist etc).

Anyway, I go for a 2 hour walk, at 3.5mph pace, and it says I've burned just over 1,500 calories! This seems bonkers to me, but I do weigh 240lbs or so? Thoughts?!

Replies

  • __Di__
    __Di__ Posts: 1,659 Member
    So I'm wearing my FT4, with chest strap and everything. Seems to be registering my heart rate accurately (measured it in line with fingers on neck/wrist etc).

    Anyway, I go for a 2 hour walk, at 3.5mph pace, and it says I've burned just over 1,500 calories! This seems bonkers to me, but I do weigh 240lbs or so? Thoughts?!

    Have you put all the details in there correctly, gender, weight, height etc? It does seem extraordinarily high, I'll give it that.
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    Yup: 6ft 4, 240lbs, Male, 29...

    MFP reckons it to be half this "/
  • acpgee
    acpgee Posts: 8,003 Member
    A nutritionist once told me that 300 cals per hour for moderate paced walking was a reasonable estimate.
  • KuroNyankoSensei
    KuroNyankoSensei Posts: 288 Member
    It's accurate for me. A 2 hour work at the same pace would probably give me 500 calories, tops, although it's more like 400-something. I'm 5'2" and somewhere below 110llbs.
  • __Di__
    __Di__ Posts: 1,659 Member
    Yup: 6ft 4, 240lbs, Male, 29...

    MFP reckons it to be half this "/

    It would be normal if it were somebody running a half marathon in two hours.

    That is way out for sure.

    How fast, just out of pure curiosity, did it say you got your HR going to?
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    According to this: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx - I burned 1,378..
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    Average was 124; Max was 158bpm
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    According to this: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx - I burned 1,378..

    Or 1,175 net.
  • olymp1a
    olymp1a Posts: 1,766 Member
    It really depends. If it was just walking at 3.5mph on a flat surface and normal temperature, then yes this seems to be a lot. But if you were walking in high temperature, high humidity, if you were climbing steps or your walk bath had a incline then yes it could be possible. All these factors make our heart beating faster meaning we burn more calories.

    On a side note I have an FT4 for more than a year and I couldn't be more happy with it, it is an invaluable tool. :)
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    It really depends. If it was just walking at 3.5mph on a flat surface and normal temperature, then yes this seems to be a lot. But if you were walking in high temperature, high humidity, if you were climbing steps or your walk bath had a incline then yes it could be possible. All these factors make our heart beating faster meaning we burn more calories.

    On a side note I have an FT4 for more than a year and I couldn't be more happy with it, it is an invaluable tool. :)

    Thanks :)

    It was earlier today, so the sun was still out, was a varying gradient... in line with the link I referred to, I'll lower the number in line with the net results that gives. We'll see come weigh-in day!
  • olymp1a
    olymp1a Posts: 1,766 Member
    BTW nice link there, it has a lot of information! Thanks! :)
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    By means of an update, it seems accurate: I've visited several other websites (incl. about.com and Jillian Michaels') and a 3 hour walk for a 244lb male at 4mph comes out at 2,200ish calories.
  • erickirb
    erickirb Posts: 12,294 Member
    Your real max HR is probably higher than the 220-age, and the formula uses % of Max HR to gauge intensity. So if the watch thinks your max HR is say 191, but your real max is 205, then it will think you are working harder than you are. I am not sure if that model allows you to adjust the max hr or not.
  • Ninkyou
    Ninkyou Posts: 6,666 Member
    I have a Polar FT4 and it's always been accurate for me!

    I think it just really depends on your weight/height and your fitness level. If you're new to exercise, you're going to be burning more calories.
  • aquarabbit
    aquarabbit Posts: 1,622 Member
    I have one as well and I feel that mine overestimates too, but I checked on one of those sites that calculate your burn by heart rate, age, and height, and it was almost the exact same. I would trust it. I guess Polar FT4's are known for overestimating when I did some research out of worry. But not by too much. And if you're still eating a deficit, I wouldn't worry too much.
  • maliciouspenguin
    maliciouspenguin Posts: 37 Member
    Thanks guys; I'll keep at it, and as long as the weight comes off, I'm not too fussed!!
  • MinnieInMaine
    MinnieInMaine Posts: 6,400 Member
    Thanks for the link - interesting stuff! I plugged in stats from my walk earlier and switched from female to male and the male calc came up with about 60% more calories burned. Wow, I knew you guys burned more but that is a huge difference! So I'd say your burn was about right. I've gotten about 800 calories for a 2 hours walk at that pace so for you to get 1500 sounds about right.
  • dbrightwell1270
    dbrightwell1270 Posts: 1,732 Member
    deleted
  • angellmoore
    angellmoore Posts: 72 Member
    I am having the opposite problem. I am wondering if my FT4 is calculating low. I went to the link above and calculated my exercise and it shows higher than my ft4 does. According to my hrm I burn ~475 calories from my run. I run about 6mph for 1 hour. The site said I should have burned ~588 and other calorie burning sites say it should burn 645 or so. I also do Jillian Michaels 30DS and my hrm says I burn only ~85, the site says I should burn ~170. I have the settings right, maybe I will re-check them just to be sure.
  • paulperryman
    paulperryman Posts: 839 Member
    So I'm wearing my FT4, with chest strap and everything. Seems to be registering my heart rate accurately (measured it in line with fingers on neck/wrist etc).

    Anyway, I go for a 2 hour walk, at 3.5mph pace, and it says I've burned just over 1,500 calories! This seems bonkers to me, but I do weigh 240lbs or so? Thoughts?!

    Have you put all the details in there correctly, gender, weight, height etc? It does seem extraordinarily high, I'll give it that.

    i was burning 20calories a minute at that weight, now at 185 i burn around 10, so it is entirely possible. you have all that extra strain on the heart and the whole body so ofcourse you are gonna burn more.

    saying that, they are not full proof, the chest straps are prone to issues and if you don't have a perfectly sealed link between your skin and the strap it can measure randomly, i use to notice mine getting stuck, randomly registering really high or low and i was dead on numerous occasions, so take it with a grain of salt but at that weight it is pretty easy to get pwards of 25 calories a minute doing just moderate exercise
  • tigersword
    tigersword Posts: 8,059 Member
    It really depends. If it was just walking at 3.5mph on a flat surface and normal temperature, then yes this seems to be a lot. But if you were walking in high temperature, high humidity, if you were climbing steps or your walk bath had a incline then yes it could be possible. All these factors make our heart beating faster meaning we burn more calories.

    On a side note I have an FT4 for more than a year and I couldn't be more happy with it, it is an invaluable tool. :)
    That's actually false. Heart beat really has nothing to do with calorie burn. The way HRMs work to estimate calories is by using your change in heart rate to estimate effort. Heart rate and VO2 Max correlate (sort of) during steady state cardio, so it can give a reasonably close estimate. Anything else that isn't steady state cardio, and your heart rate has absolutely zero correlation with calorie burn. The hills might have increased calorie burn slightly, but temperature and humidity have no real effect.
  • clew77
    clew77 Posts: 34
    I'm beginning to think mines a load of rubbish, either that or the class instructors are lying.
    I go to a kettle bell class twice a week and at the end the instructor always says .. you would have burned between 800-1200 cals depending on what weight you used.
    I always use a 8kg for an hours long class .. work my butt off and burn 400 .. if that !!

    Frustrating.
  • marsellient
    marsellient Posts: 591 Member
    According to this: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx - I burned 1,378..

    Thanks for this link. I checked it out and found the net pretty consistent with my Polar FT4. Always nice to have another tool. I find it motivating. ????
  • cjs3001
    cjs3001 Posts: 273 Member
    My FT4 is pretty accurate for most things but it does go a little crazy for walking. But if tigersworld said it was about a change in heart rate then maybe waiting to cross roads and things like that cause a bit of fluctuation which bumps it up. I'm not sure, you don't seem to be too put out by it, just take it with a pinch of salt and maybe don't eat all of them back.
    And well done on such a good walk too :smile:
  • Parmcat
    Parmcat Posts: 268 Member
    I have the FT4 and have found it the opposite to MFP. I worked out yesterday for 90 in doing weights and treadmill HITT, and burned almost 500 cal, and MFL said I burned 1600.

    I feel mine is dialed in pretty good.

    I am 43, 6'0 and 318lbs
  • tigersword
    tigersword Posts: 8,059 Member
    I'm beginning to think mines a load of rubbish, either that or the class instructors are lying.
    I go to a kettle bell class twice a week and at the end the instructor always says .. you would have burned between 800-1200 cals depending on what weight you used.
    I always use a 8kg for an hours long class .. work my butt off and burn 400 .. if that !!

    Frustrating.
    HRMs CANNOT calculate calorie burns for strength training. They can only give estimates for steady state cardio, strength training is an anaerobic activity that uses different energy systems to burn calories, an HRM is not equipped to register or calculate that kind of activity. It can read your heart rate. Your heart rate has no effect on calorie burn while doing anaerobic activity.

    Also, the instructors are probably full of it. Calorie burn is highly individualized based on lean mass of the person in question, impossible to give a blanket number like that.
  • clew77
    clew77 Posts: 34
    I'm beginning to think mines a load of rubbish, either that or the class instructors are lying.
    I go to a kettle bell class twice a week and at the end the instructor always says .. you would have burned between 800-1200 cals depending on what weight you used.
    I always use a 8kg for an hours long class .. work my butt off and burn 400 .. if that !!

    Frustrating.
    HRMs CANNOT calculate calorie burns for strength training. They can only give estimates for steady state cardio, strength training is an anaerobic activity that uses different energy systems to burn calories, an HRM is not equipped to register or calculate that kind of activity. It can read your heart rate. Your heart rate has no effect on calorie burn while doing anaerobic activity.

    Also, the instructors are probably full of it. Calorie burn is highly individualized based on lean mass of the person in question, impossible to give a blanket number like that.

    Ahh that's made me feel better then, was a bit disheartening after every class!!
  • kinmad4it
    kinmad4it Posts: 185 Member
    I thought your heart rate had to be up to a certain level for a HRM to have any sort of effectiveness. At least for me, walking never gets my heart rate up enough, no matter how fast I walk.
    I tried I out the week I got my FT4 and my heart rate never got above 105, which is nowhere near high enough to give any sort of accurate calorie reading.

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