How to test HRM for how accurate calorie burn is

13

Replies

  • callieboom
    callieboom Posts: 30
    bump for later
  • samcat2000
    samcat2000 Posts: 106 Member
    I can't wait to try this with my new Polar ft-40.

    I'm new to commuting on my road bike to work - 39 miles R/T. Going to work the other day, my HRM said I burned 924 cal at the end of the ride. It was a tough ride. Forgot my asthma inhaler, slight head wind, etc. and I just had to overall work my butt off. Then that evening, rode same route home. Legs were so tired but lungs were not and well thankfully I had the most AMAZING tail wind or I might not have made it home. HRM said I burned 595 cal. Pretty big difference but I suppose that the huge tail wind could have helped me that much??? I hope my new HRM doesn't suck!
  • heybales
    heybales Posts: 18,842 Member
    I can't wait to try this with my new Polar ft-40.

    I'm new to commuting on my road bike to work - 39 miles R/T. Going to work the other day, my HRM said I burned 924 cal at the end of the ride. It was a tough ride. Forgot my asthma inhaler, slight head wind, etc. and I just had to overall work my butt off. Then that evening, rode same route home. Legs were so tired but lungs were not and well thankfully I had the most AMAZING tail wind or I might not have made it home. HRM said I burned 595 cal. Pretty big difference but I suppose that the huge tail wind could have helped me that much??? I hope my new HRM doesn't suck!

    You just hit a situation as to WHY a HRM can be thrown off trying to associate HR with a calorie burn.

    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

    You were also taking in less air with asthma, so you had to breath more, blood had to bump more, to get the required oxygen out of what you were breathing.

    That higher HR was seen by HRM as harder effort - which it was for your body getting oxygen, but not necessarily in the ride.

    More important than those figures of calories, what did the HRM say for what it actually does, monitoring the heart rate, between the 2 rides?
  • ladyraiah
    ladyraiah Posts: 110 Member
    bump for later.
  • jessicapk
    jessicapk Posts: 574 Member
    bump! this is the most intelligent forum post I believe I've run across on this site and it's information that I'm really looking forward to reading when I'm home and relaxed with a nice steady heartbeat :)
  • __Di__
    __Di__ Posts: 1,658 Member
    Ive just ordered my Polar FT4 HRM and so just to clarify, we are suppose to add our weight that we get when we weigh fully clothed instead of what we would way Naked ?

    Ok so are the HRM accurate then or not ?

    Not.

    Narrow range that has a chance.

    http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study

    And that is for one of the more expensive Polars that self tests, and allows correcting the important stats.
    Yours has no such stats available to change. It assumes worse BMI, worse fitness level - which is bad assumption.

    Men aren't off the hook either.

    http://www.asep.org/asep/asep/JEPonlineOctober2011Esco.pdf

    And yes to weight doing the exercise.

    SO what are you trying to say ? That my Polar Ft4 HRM is crap ? I chose that one because of all the reviews ive seen here on MFP and its one that I can afford which was still higher then I wanted to pay.

    No, the Polar FT4 is not crap.

    It measures HR, it gives the calorie burn, it tells you your max HR and average HR during a cardio workout, it will tell you how long you were in the zone for (which contrary to what many will say, does have a time and place during certain training regimes) and it will also act as a stopwatch.

    To be perfectly honest, I couldn't care less how many calories it displays, it gives me a rough idea and that is good enough for me. I have found it extraordinarily useful, however, when keeping my eye on my HR during my runs, especially if I am on a particular training session that requires I keep my HR below a certain level or if I am doing interval training (to ensure my HR has gone back down to 120bpm before starting the next rep for instance).

    Enjoy your FT4, I have found it excellent. I do, however, refuse to get bogged down in stats and whether something is 100%, who cares, it is your training which counts, not a piece of equipment. The HRM should be used as a guide, not the be all and end all.
  • endoftheside
    endoftheside Posts: 568 Member
    Tested today with my PolarFT60 (weight and fit test up to date in the HRM).

    After 10 minute warmup, did 20 minutes at 3.8mph and 2.0 incline.

    HRM = 123, Calculator = 119, so only about 3% off. Not bad!
  • Mav3rick54
    Mav3rick54 Posts: 180 Member
    bump to try later
  • My_Own_Worst_Enemy
    My_Own_Worst_Enemy Posts: 218 Member

    Well, have fun testing.



    Thanks, but I am having way too much fun using TDEE. No need for this BS. Thanks though! :drinker:
  • 42hockeymom
    42hockeymom Posts: 521 Member
    Interesting.


    Bump
  • heybales
    heybales Posts: 18,842 Member

    Well, have fun testing.

    Thanks, but I am having way too much fun using TDEE. No need for this BS. Thanks though! :drinker:

    Is a tool you don't happen to use or need BS?

    Is a tool that others do want to use BS, or the method to use that tool better?

    Very true, TDEE method doesn't need it, except in some cases of big calorie burns where you really need to make up some of what you did, and waiting a month to find out how the TDEE and weight loss came out is a tad too long for performance if you under ate too great.

    But I'm sure it'll be nice for someone to have your opinion, and I guess your desire to bump and keep up with this topic since that puts it at top of recent posts too.
  • mtrautwe
    mtrautwe Posts: 4 Member
    bump for reference
  • SephiraRose
    SephiraRose Posts: 766 Member
    so much info thanks
  • heybales
    heybales Posts: 18,842 Member
    so much info thanks

    And it's a great test to run every 1 month, because as you get more fit, the speed and incline increase to hit the same HR as last test can be very impressive.
  • MissJay75
    MissJay75 Posts: 768 Member
    bump
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
    It really differs from person to person, but my cheap polar seems to be pretty accurate in MY case. MFP values are almost 35% lower than what my HRM suggests. I even use the gross values as eat-back and the weight has been coming off in exact values. Maybe things will be different as I itch my way closer to my target weight or as I become more fit, who knows. Do you think trying for a more accurate approach would yield significantly better results? Or should I stick to what's been working for me, albeit too simple? Is there a chance MFP is underestimating my TDEE?
  • heybales
    heybales Posts: 18,842 Member
    It really differs from person to person, but my cheap polar seems to be pretty accurate in MY case. MFP values are almost 35% lower than what my HRM suggests. I even use the gross values as eat-back and the weight has been coming off in exact values. Maybe things will be different as I itch my way closer to my target weight or as I become more fit, who knows. Do you think trying for a more accurate approach would yield significantly better results? Or should I stick to what's been working for me, albeit too simple? Is there a chance MFP is underestimating my TDEE?

    So if the loss is as the numbers would indicate, you do know that MFP's maintenance estimate (not TDEE because they include no exercise) and your HRM's calorie burn estimate added together really do seem to be your TDEE.

    Since indeed the HRM is giving gross not net burn, meaning you are eating more than was burned extra compared to what would have been burned anyway, that means MFP's estimate of maintenance is lower than reality.

    So indeed, that should cause some differences eventually, on both of those estimates.

    Depending on HRM, you getting fit may not be correctly reflected in calorie burn estimate, and it's inflated burn.

    I'd suggest that if MFP values are that below your HRM, your activity level for non-exercise is probably higher than what you have selected.
    Your inflated calorie burns are just making up the slack.

    At this point, you can go with results.
    If you ate this much in total average daily over 4 weeks, and you lost this much over same 4 weeks, then you can do the math to figure out your real TDEE.
    Then adjust accordingly.
    You'll want to watch your weight loss goal too, less to lose should be slower loss - or your body will force it on you anyway.
  • Tanya949
    Tanya949 Posts: 604 Member
    Bump
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
    Necro for safe-keeping.
  • Lunaaa_88
    Lunaaa_88 Posts: 1 Member
    did you try it with your polar? was it accurate? curious to know.. I have a polar too.
  • JorgeGonzales
    JorgeGonzales Posts: 27
    I will try this. Thanks
  • heybales
    heybales Posts: 18,842 Member
    did you try it with your polar? was it accurate? curious to know.. I have a polar too.

    Someone on 2nd page reported their Polar test, not great.
    Other guy did on other thread - 20 min test at mere 120 bpm, Polar was 11% below.

    You can't compare to others, as your fitness level is your own.

    I never did test that I recall, and no treadmill to use now or I'd test it. I actually should test it on my next run.

    I used the site indicated with an outdoor run, and stats on total elevation gain (and since I came back down, total loss), which both count as grade, so doubled.

    So total gain x 2 / miles / 5280 x 100 = grade %
    Had my mileage, had my time, had my pace, had my weight.

    2 calories different than my personal VO2max formula. And that was very hilly route.

    Just did another run today, flatter, actually Jog and walk intervals, same thing, a tad bit of heat elevated HR, so my formula was about 20 over calculated.

    My Garmin remains a problem since there is no way to tell it your VO2max stat, so it's used for just getting all the other stats that I like.

    So maybe I can test the Polar actually.
  • bellesouth18
    bellesouth18 Posts: 1,071 Member
    Bumping to have the information.
  • heybales
    heybales Posts: 18,842 Member
    Thanks heybales for providing the link to this page on Pu's profile! I will look into this, although my current conversion factor seems to be acceptable for now.

    That is, I attempted to calibrate to a treadmill while running and came up with a multiplicative factor of 0.65 for my cheap Timex HRM. The beats per minute is accurate thus far.

    Question: does a low resting heart rate and a quicker recovery time tend to indicate that the person is in better shape?

    Low resting HR indicates heart can pump enough oxygen around for resting level requirements at lower value. Good fitness level.

    Quick recovery time indicates same thing.

    If you really want better accuracy, and you have treadmill, come up with your own personal HR formula.
    Depending on current fitness level, may improve enough to do this monthly or two.

    http://www.myfitnesspal.com/blog/heybales/view/getting-your-personalized-calorie-burn-formula-663625
  • Jennifer_Lynn_1982
    Jennifer_Lynn_1982 Posts: 567 Member
    bump
  • AnnPT77
    AnnPT77 Posts: 34,269 Member
    Glad you re-linked this in a current thread. It's a gem, as with most of your helpful posts. Thanks!
  • NorthCascades
    NorthCascades Posts: 10,968 Member
    This is an old thread but the info is still relevant and some of the posters are still here. 🙂

    I tested against a direct force power meter. I've found the HRM is almost always over, by up to 40% but usually much less. In one case of was off by much less than 1%. No obvious way to tell where any ride was along that range, intervals vs steady vs the way people normally ride bikes made no observable change to the HRM's accuracy.
  • heybales
    heybales Posts: 18,842 Member
    As I get out of summer a HR-based formula using a VO2max estimate starts getting within 5% of power meter. Like when I'm not sweating off 5-10 lbs for 1-2 hr ride.
  • djaxon1
    djaxon1 Posts: 82 Member
    edited November 2020
    I'm glad calories aren't my priority - it's a minefield !
    Putting in 3mph ,60min level walk , 200lbs - exrx gives 315
    42.195 gives 513cals ? ?
    keisan 276 , must put in details so 45yr/5'9
    shapesense 360
    caloriesburnedhq. 333
    healthline 260+

    For a much harder incline walk my old treadmill reads low but no inputs at all
    Huawei health app with cheap wrist band reads low -ish
    Old Polar with vo2 input reads middling , same for myworkouts app , both with chest straps.
    exrx and 42.195 both give highest cals results by 10-15%

    This blog "Intensity not HR" as title , https://www.myfitnesspal.com/blog/Azdak?month=201005
    States HR is not a direct indicator of caloric burn.
    And I get a lot of cardio drift as described here - https://www.myfitnesspal.com/blog/Azdak?month=201106
    30% more cals "burned" in 2nd half hour of a steady state 1 hr workout !" As stated - No way !

    There seems a big disconnect with HRM's calorie estimates
  • AnnPT77
    AnnPT77 Posts: 34,269 Member
    djaxon1 wrote: »
    I'm glad calories aren't my priority - it's a minefield !
    Putting in 3mph ,60min level walk , 200lbs - exrx gives 315
    42.195 gives 513cals ? ?
    keisan 276 , must put in details so 45yr/5'9
    shapesense 360
    caloriesburnedhq. 333
    healthline 260+

    For a much harder incline walk my old treadmill reads low but no inputs at all
    Huawei health app with cheap wrist band reads low -ish
    Old Polar with vo2 input reads middling , same for myworkouts app , both with chest straps.
    exrx and 42.195 both give highest cals results by 10-15%

    This blog "Intensity not HR" as title , https://www.myfitnesspal.com/blog/Azdak?month=201005
    States HR is not a direct indicator of caloric burn.
    And I get a lot of cardio drift as described here - https://www.myfitnesspal.com/blog/Azdak?month=201106
    30% more cals "burned" in 2nd half hour of a steady state 1 hr workout !" As stated - No way !

    There seems a big disconnect with HRM's calorie estimates

    5'9", male, 200lbs, age 45: Estimated TDEE at sedentary, around 2200 calories daily, best guess. (Could be wrong, sure - high or low.)

    Lowest exercise calorie estimate I see in your post: 260 calories.
    Highest exercise calorie estimate I see in your post: 513 calories.

    Maximum difference in estimates, 253 calories. 11.5% of base TDEE.

    Every day? Then if the most minimal normal calorie deficit of 250 daily (half a pound a week), and the lowest estimate is right (no reason to believe it is, vs. a higher one), you wipe out your deficit and maintain weight. At loss goal of a pound a week, you lose half a pound instead of a pound.

    In a context where you sensibly adjust intake based on results? No harm, after the first few weeks (before adjusting).

    Less than every day exercise? Less effect.

    "Minefield"? "Big Disconnect"? Meh. Close enough for gubmint work.

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