Just got a Polar FT4 - v different calorie burn to expected!

Hi, as the title says I just got a Polar FT4 HRM today. Set it up this afternoon (weight, hieght, age etc) and went off for a walk tonight to "test drive" it.

Polar FT4 says I walked for 37 mins, had average HR of 139, max of 152, burnt 37 calories.
I walked 2.2 miles - so in 37 minutes this is about 3.5 mph. MFP says 37 minutes walking at 3.5 mph(brisk pace) = 192 calories. I'd always thought as a rough estimate to allow about 100 calories per mile walked so this was pretty much what I'd expected.

I had expected the HRM to show a lower calorie count than MFP, as I thought that MFP tends to over estimate. But in this case it's the other way round. So now not sure which is closer to the truth? Any thoughts?

(If it makes any difference I am overweight (180 lb) but have been losing weight (down from 240 in the past 6 months) and doing exercise several times per week.)
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Replies

  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    100 calories per mile is for running. My understanding was walking was almost half.
    (Study outlined and linked in article)
    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning?page=single

    Also a great post to help make sure you HRM is set up accurately
    http://www.myfitnesspal.com/topics/show/750920-spreadsheet-for-bmr-tdee-deficit-macro-calcs-hrm-zones
  • wouldn't use a hrm for walks, only for workouts.
  • jaz050465
    jaz050465 Posts: 3,508 Member
    You need a fitbit or Bodymedia fit for walking
  • jaz050465
    jaz050465 Posts: 3,508 Member
    100 calories per mile is for running. My understanding was walking was almost half.
    (Study outlined and linked in article)
    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning?page=single

    Also a great post to help make sure you HRM is set up accurately
    http://www.myfitnesspal.com/topics/show/750920-spreadsheet-for-bmr-tdee-deficit-macro-calcs-hrm-zones

    Are you comparing equal times or distances?
  • JustJennie1
    JustJennie1 Posts: 3,749 Member
    wouldn't use a hrm for walks, only for workouts.

    Just curious as to why? I've worn mine for walks that I've gone on. Mind you they're far from strolls. The pace is between 4 and 4.5 mph, the terrain is very hilly and hard and depending on the route my walk is 2.5-3.5 miles. My HR can get up to 150 during one of my vigorous walks and I break a sweat. It's definitely a workout so why wouldn't one use their HRM when they walk?
  • dawningr
    dawningr Posts: 387 Member
    What's important is the calories burned. The Polar is going to be most accurate for that, not for distance.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    100 calories per mile is for running. My understanding was walking was almost half.
    (Study outlined and linked in article)
    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning?page=single

    Also a great post to help make sure you HRM is set up accurately
    http://www.myfitnesspal.com/topics/show/750920-spreadsheet-for-bmr-tdee-deficit-macro-calcs-hrm-zones

    Are you comparing equal times or distances?

    Equal distance.

    The article explains it better.
    You can use the formulas below to determine your calorie-burn while running and walking. The "Net Calorie Burn" measures calories burned, minus basal metabolism. Scientists consider this the best way to evaluate the actual calorie-burn of any exercise. The walking formulas apply to speeds of 3 to 4 mph. At 5 mph and faster, walking burns more calories than running.

    Your Total Calorie Burn/Mile
    Your Net Calorie Burn/Mile
    Running
    .75 x your weight (in lbs.)
    .63 x your weight
    Walking
    .53 x your weight
    .30 x your weight
    Adapted from "Energy Expenditure of Walking and Running," Medicine & Science in Sport & Exercise, Cameron et al, Dec. 2004.
  • BlueEyedTXmom
    BlueEyedTXmom Posts: 179 Member
    How long does it say you were in the zone for? That seems really low. Are you sure it was connected the whole time? The blinking heart at the top? If you have the strap that came with it make sure you wet the sensors well. I always use mine when walking.
  • jamantha
    jamantha Posts: 118 Member
    wouldn't use a hrm for walks, only for workouts.

    Just curious as to why? I've worn mine for walks that I've gone on. Mind you they're far from strolls. The pace is between 4 and 4.5 mph, the terrain is very hilly and hard and depending on the route my walk is 2.5-3.5 miles. My HR can get up to 150 during one of my vigorous walks and I break a sweat. It's definitely a workout so why wouldn't one use their HRM when they walk?

    Glad it's not just me that was wondering this! I'm not as fast as you (yet - working on it though!) but my heart rate is up, I would find it a challenge to hold a conversation if anyone was with me, and I get sweaty (even in this cold weather).
  • squatsandlipgloss
    squatsandlipgloss Posts: 595 Member
    I don't really get it. Your HRM measures your heart rate exactly, takes into account your stats and thus can tell you 50x more accurate than any website that only gives you estimates and has no flippin clue what your heart rate does...
  • wouldn't use a hrm for walks, only for workouts.

    ERRM why? A walk can be a 'work out'.
  • jamantha
    jamantha Posts: 118 Member
    How long does it say you were in the zone for? That seems really low. Are you sure it was connected the whole time? The blinking heart at the top? If you have the strap that came with it make sure you wet the sensors well. I always use mine when walking.

    It says I was in the zone (haven't adjusted that from the default of 116 - 151) for all but 30 seconds of my 37 minute walk. I didn't look closely at the display, so can't comment on the blinking heart, but I glanced at the display every now and then and it was displaying something betwen 130 and 150 every time I looked at it. I'll bear in mind about wetting the sensors well though - I did wet them a bit, but maybe not enough?

    BTW do you think the FT4's 300-odd calorie count is low? I was thinking it was too high!
  • wareagle8706
    wareagle8706 Posts: 1,090 Member
    wouldn't use a hrm for walks, only for workouts.

    ^ignore this person^ that is wrong.

    There has to be a problem with the HRM, in my opinion. Because I'm pretty sure I would be able to burn more then 1 calorie per minute while walking. Did you apply the strap correctly? Did it tell you to wet the strap before applying? Did you make sure it found your heart rate and never read "00" on the watch? sometimes it can't get a good read and that will inevitably give you an incorrect calorie count. I would try again.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    I don't really get it. Your HRM measures your heart rate exactly, takes into account your stats and thus can tell you 50x more accurate than any website that only gives you estimates and has no flippin clue what your heart rate does...

    a very common misconception.

    Heart rate isn't directly related to calories burned. There is a relationship between HR and VO2 max during steady state cardio that allows for an estimate of calories burned.
    And it is relatively easy to estimate calories burned for exercise like walking.
    "INTENSITY x BODY WEIGHT

    That’s it. (Factors like age, height, and gender are necessary for heart rate monitor estimates, but those factors are only needed for HRMs, as will be explained later).

    So: more intense workloads will burn more calories than less intense workloads and, at any given workload, heavier people will burn more calories than lighter people.

    Next: the energy cost for any given exercise workload is relatively fixed. For example the energy cost of walking at 3.0 mph and 5% elevation on a treadmill (w/out holding on) is approximately 5.4 METs (a MET is a measure of aerobic intensity. That 5.4 MET intensity is the same for everyone—regardless of age, gender, or fitness level.

    So, every given speed, elevation, watt level, etc, has a relatively fixed energy cost. If we can measure the workload, and we have formulae that can accurately calculate the energy cost for a given workload, it is straightforward arithmetic to determine the calories expended. "
    http://www.myfitnesspal.com/blog/Azdak

    A more indepth explaination
    http://www.myfitnesspal.com/blog/Azdak?month=201005
  • JustJennie1
    JustJennie1 Posts: 3,749 Member
    100 calories per mile is for running. My understanding was walking was almost half.
    (Study outlined and linked in article)
    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning?page=single

    Also a great post to help make sure you HRM is set up accurately
    http://www.myfitnesspal.com/topics/show/750920-spreadsheet-for-bmr-tdee-deficit-macro-calcs-hrm-zones

    Are you comparing equal times or distances?

    Equal distance.

    The article explains it better.
    You can use the formulas below to determine your calorie-burn while running and walking. The "Net Calorie Burn" measures calories burned, minus basal metabolism. Scientists consider this the best way to evaluate the actual calorie-burn of any exercise. The walking formulas apply to speeds of 3 to 4 mph. At 5 mph and faster, walking burns more calories than running.

    Your Total Calorie Burn/Mile
    Your Net Calorie Burn/Mile
    Running
    .75 x your weight (in lbs.)
    .63 x your weight
    Walking
    .53 x your weight
    .30 x your weight
    Adapted from "Energy Expenditure of Walking and Running," Medicine & Science in Sport & Exercise, Cameron et al, Dec. 2004.

    I don't agree with that. I calculated my calories burned/mile per the "running" calculation and it was way, way off. They're not taking into consideration how fast someone is running. I know that the faster I run the more calories I burn. I most definitely burn more than 88 calories/mile and sometimes more than 100.
  • wareagle8706
    wareagle8706 Posts: 1,090 Member
    How long does it say you were in the zone for? That seems really low. Are you sure it was connected the whole time? The blinking heart at the top? If you have the strap that came with it make sure you wet the sensors well. I always use mine when walking.

    It says I was in the zone (haven't adjusted that from the default of 116 - 151) for all but 30 seconds of my 37 minute walk. I didn't look closely at the display, so can't comment on the blinking heart, but I glanced at the display every now and then and it was displaying something betwen 130 and 150 every time I looked at it. I'll bear in mind about wetting the sensors well though - I did wet them a bit, but maybe not enough?

    BTW do you think the FT4's 300-odd calorie count is low? I was thinking it was too high!

    Oh wait!! You meant 370 calories?!? Your original post says "37" hahahaha

    Nah you're good, girl. go with the HRM.
  • jamantha
    jamantha Posts: 118 Member
    I don't really get it. Your HRM measures your heart rate exactly, takes into account your stats and thus can tell you 50x more accurate than any website that only gives you estimates and has no flippin clue what your heart rate does...

    That's what I was thinking, which is why I got it. But I was really expecting it to give a LOWER value than the MFP estimate. So was a bit confused when it read higher, and wanted to know if I was doing something wrong with it. If the higher value is right then fantastic! But if I've messed up and the HRM is reading too high, then I want to know!. I'll check I've set it up properly tomorrow when I've got a little more time.

    Thanks for the replies, everyone :smile:
  • You need a fitbit or Bodymedia fit for walking

    A HRM (set up correctly) will be tons more accurate than a Fitbit and a Bodymedia.

    I have both a Fitbit One and a Polar HRM. I use both during my activities. I go hiking every weekend (which is walking at various different inclines) and my HRM calorie burn made way more sense than my Fitbit.
  • jamantha
    jamantha Posts: 118 Member

    Oh wait!! You meant 370 calories?!? Your original post says "37" hahahaha

    Nah you're good, girl. go with the HRM.

    Ooops!! My mistake, sorry. That original post should have read 317 calories readout, not 37! Sticky keyboard (and lack of proof reading) to blame :grumble:
  • I'm glad someone cleared up the 37 calories the OP originally posted. I was gonna to recommend returning it and getting a new one.

    I think your burn was more accurate with the HRM than MFP.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    100 calories per mile is for running. My understanding was walking was almost half.
    (Study outlined and linked in article)
    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning?page=single

    Also a great post to help make sure you HRM is set up accurately
    http://www.myfitnesspal.com/topics/show/750920-spreadsheet-for-bmr-tdee-deficit-macro-calcs-hrm-zones

    Are you comparing equal times or distances?

    Equal distance.

    The article explains it better.
    You can use the formulas below to determine your calorie-burn while running and walking. The "Net Calorie Burn" measures calories burned, minus basal metabolism. Scientists consider this the best way to evaluate the actual calorie-burn of any exercise. The walking formulas apply to speeds of 3 to 4 mph. At 5 mph and faster, walking burns more calories than running.

    Your Total Calorie Burn/Mile
    Your Net Calorie Burn/Mile
    Running
    .75 x your weight (in lbs.)
    .63 x your weight
    Walking
    .53 x your weight
    .30 x your weight
    Adapted from "Energy Expenditure of Walking and Running," Medicine & Science in Sport & Exercise, Cameron et al, Dec. 2004.

    I don't agree with that. I calculated my calories burned/mile per the "running" calculation and it was way, way off. They're not taking into consideration how fast someone is running. I know that the faster I run the more calories I burn. I most definitely burn more than 88 calories/mile and sometimes more than 100.

    The faster you run, the more miles, so the calculation will be higher. Although I did say it is average. Its not meant to be exact although there are online calculators that account for pace.

    How do you know what your calorie burn is?
  • dwntwnpengrl
    dwntwnpengrl Posts: 49 Member
    My FT4 occasionally has fits and stops tracking. It doesn't seem to like Tuesdays or anytime I go for more than a day without wearing it. Totally scientific data ;-)

    But, my guess is that at some point during your walk, it lost signal with the HRM. It would still track time.

    I have to place the HRM in just the right place (or left in my case) or it won't transmit correctly.
  • DPernet
    DPernet Posts: 481 Member
    wouldn't use a hrm for walks, only for workouts.

    ERRM why? A walk can be a 'work out'.

    Heart rate monitors don't work very well for 'non steady' workouts like weight lifting for example. They are meant for workouts where the heart rate is fairly high (+100 ish) and fairly steady. They are pretty useless when the heart rate is too low or changes by a large amount over a short time frame......although tbh a heart rate of 152 bpm when walking seems a bit high, it should give a very accurate reading if the heart rate was high and steady during the whole walk.

    I haven't got a FT4, but mine has the option of entering your VO2 max number in the settings. This would make it a bit more accurate as long as you've established your VO2 max number correctly of course :wink:
  • dwntwnpengrl
    dwntwnpengrl Posts: 49 Member
    Ooops!! My mistake, sorry. That original post should have read 317 calories readout, not 37! Sticky keyboard (and lack of proof reading) to blame :grumble:

    Nevermind what I said. 317 actually sounds about right.
  • wareagle8706
    wareagle8706 Posts: 1,090 Member

    Oh wait!! You meant 370 calories?!? Your original post says "37" hahahaha

    Nah you're good, girl. go with the HRM.

    Ooops!! My mistake, sorry. That original post should have read 317 calories readout, not 37! Sticky keyboard (and lack of proof reading) to blame :grumble:

    You can edit your original post by clicking "edit" in the bottom right corner of the post. So that others that are new don't get confused.
  • bluebear_74
    bluebear_74 Posts: 179
    That seems too low if your heart rate was up to 130-150. Sometimes when I don't wet it properly it gives me low heart rates, or if I haven't given it a good wash and the sensors are blocked (but yours is new and shouldn't have that issue). Another thing might be that you started too hard too fast, because it takes a minute or two to find your pace, so if you're going too hard early, if might think that's your "resting/easy" pace, so you have to go extra hard to get it up. Mine usually tells me anything above 134-ish is my fitness building (and not fat burning) zone, however I went hard early with Insanity the other date so my heart rate was up early and it told me anything above 150 is my fitness zone (I had a lower calorie burnt than usual even though my heart rate was up higher than usual).

    Maybe next time start slow, then slowly go faster.
  • bluebear_74
    bluebear_74 Posts: 179

    Oh wait!! You meant 370 calories?!? Your original post says "37" hahahaha

    Nah you're good, girl. go with the HRM.

    Ooops!! My mistake, sorry. That original post should have read 317 calories readout, not 37! Sticky keyboard (and lack of proof reading) to blame :grumble:

    You can edit your original post by clicking "edit" in the bottom right corner of the post. So that others that are new don't get confused.
    LOL! Well 317 sounds just about right! I usually get the around same for a 40 minute workout with my heart rate between 130-150.
  • wouldn't use a hrm for walks, only for workouts.

    ERRM why? A walk can be a 'work out'.

    Heart rate monitors don't work very well for 'non steady' workouts like weight lifting for example. They are meant for workouts where the heart rate is fairly high (+100 ish) and fairly steady. They are pretty useless when the heart rate is too low or changes by a large amount over a short time frame......although tbh a heart rate of 152 bpm when walking seems a bit high, it should give a very accurate reading if the heart rate was high and steady during the whole walk.

    I haven't got a FT4, but mine has the option of entering your VO2 max number in the settings. This would make it a bit more accurate as long as you've established your VO2 max number correctly of course :wink:

    So based on what you said a walk can be a work out. Not everyone's walk is a causal stroll in the park. Mine aren't. :drinker:

    Neither are my hikes...my knees are paying for it this week :sad:
  • vickiessecret
    vickiessecret Posts: 119 Member
    I also just got my polar ft4 last night & used it along with my cheap other hrm on my other wrist, just to see what the difference would be. The polar hrm is telling me I'm burning less calories, so my other hrm & this site is over estimating all of the calories I burned, so I'm going to go by what the Polar is telling me, since the chest strap is right their monitoring my heart. It's good to know though :)
  • Shannonigans84
    Shannonigans84 Posts: 693 Member
    My FT4 always has higher counts than MFP. It's different for everyone but I trust my HRM for my fast walks that aren't really considered work outs :wink: