Polar FT4 calories vs MFP calories

sola24
sola24 Posts: 334 Member
edited November 9 in Fitness and Exercise
I am current doing PiYo and T25 Beta (Completed Alpha.. Woohoo!!!) and recently got a Polar FT4. Before this I used to log estimate calories from MFP database. After wearing my HRM I am seeing I am burning 200-250 per workout while according to MFP its 120-150. Can there be so much difference? Everyone says MFP overestimates calories but for me it is underestimating? Any advices?
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Replies

  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    Your HRM is overestimating expenditure as you're using it outside of it's design parameters.
  • sola24
    sola24 Posts: 334 Member
    Then how to log my workouts? any idea? What does everyone else do?
  • MinnieInMaine
    MinnieInMaine Posts: 6,400 Member
    Since PiYo and T25 aren't on the MFP database, you've been using listings that weren't specific to those particular exercises. I've never done either of those workouts so I can't speak to burn/intensity but perhaps you've been burning more all along. While HRMs can be helpful, they're really only intended for steady state cardio (walking, running, biking, etc) so they're not very accurate for circuit training or strength training workouts. Maybe take the number from the HRM and subtract 100-20% to be sure.

    Consider this... If you've been eating back your exercise calories all along and have been losing as expected, your burn estimates may have actually been on target. Some of this process is trial and error and estimates that have to be played with a bit to find the right balance.
  • sola24
    sola24 Posts: 334 Member
    PiYo is combination of Pilates and Yoga but it is not slow as we are moving around continuously. T25 is mainly cardio.
  • krysmuree
    krysmuree Posts: 326 Member
    edited January 2015
    I've consistently used my FT4 for strength training/cardio workouts for years and when I was using MFP before (I should add this is standard DVD ST & cardio, in addition to treadmill, outdoors running/jogging, hiking - not gym ST), I logged exactly what my HRM said and only ate the calories back if I was really hungry. I lost weight consistently. It might be for "steady state cardio" but I have used it for everything and have never had an issue losing weight when following it. I'm so surprised to hear others have had issues! :\
  • Swimgoddess
    Swimgoddess Posts: 711 Member
    MinnieInMaine is right. I've used a Polar F7 model for upwards of 8 months before switching to a BodyMedia Link for a year. With my HRM, the more I worked out, the more weight I gained because I was eating back all my HRM-estimated exercise calories and primarily doing circuit weight training workouts and Zumba/Hip Hop classes with only a little C25K thrown in. I wore both my HRM (during exercise only) and BodyMedia (23/7) for about a week before ditching the HRM. Here's why:

    1 hour of Circuit Weight Training:
    HRM - 500 to 800 calories burned
    Body Media - 180 to 300 calories burned

    55 minute Zumba Class:
    HRM - 700 to 900 calories burned
    Body Media - 400 to 700 calories burned

    30 minute C25K (only week 3):
    HRM - 280 calories burned
    Body Media - 250 calories burned

    It was a hard lesson for me to learn. After 8 months of being in this mindset that I was burning...so...much it was very VERY hard to choke down the fact that I was indeed not burning even close to what I thought. But after 8 months of inexplicably gaining weight the more I worked out, it only took me a week to accept that the Body Media was far more accurate when it came to my workout habits and part ways with my HRM. As you can see, the closest the HRM got was during C25K. So if endurance training is your thing, that's the way to go.

    Also, HRMs have mostly only been tested on men. Their margin of error on men is <8%. On women, they found it can be off by like, 20% or more.

    As for how MFP figures out its calorie formulas: MFP assumes every woman is 26% body-fat. Depending on how off you are from 26%, their calculation on your burns will be off. Google Katch-McArdle formula to find your real BMR. You'll need to know your body-fat % from either a tape-measure online calculator (Heath Central's is pretty good), calipers, bodpod, or DEXA (most people don't have access to the latter stuff though). I don't trust my Tanita body-fat scale, that thing is WAY off (+15%... eek!)

    Above is simply how my comment applies to you. Read on only if you want to avoid my further personal mistakes with tracking devices.

    ***
    Now... that said, I also ditched my Body Media after a year of use (I had a tan line and a permanent indent in my arm from wearing it pretty much 23hrs a day). It was very difficult as I was pretty dependent/addicted. I even put together a massive Excel database that tracked more than MFP ever could, breaking down my burns from different types of exercise each week, sodium intake, macros, ToM, etc. In the end... I gained 20lbs in a year, yet "by the math" of calories in vs calories out, I should have *lost* like, 30lbs. I was insanely frustrated. I was burnt... out...

    Lessons learned:
    1.) I learned the hard way that I was overtraining because I figured, "hey, when it comes to the gym, more is better!" (chasing my 55min Zumba class with 45min of circuit weight training), plus... I only wanted to shower so many times a day. I shot from 22% to 25% body fat in 2 months of this and it was one of the few times I was working out more than I ever had in my entire life, including a 6 year stint in the Marines. Turns out, unless you have a nutritionist's knowledge-base and some serious dedication in your diet, you can't avoid the fact that around the 48-minute mark of exercise your body flips a switch from burning fat (peaked levels of latent testosterone and decreased cortisol levels) to burning muscle (spiking cortisol levels and plummeting latent testosterone levels after this time mark). Now I know that a burn is only a "burn" until I've worked out around 45-50 minutes. I have to wait 3-4hrs if I'd like to work out more in one day because my hormones need to reset.

    2.) I wasn't eating totally crappy, but I wasn't perfect either. A calorie isn't really "a calorie is a calorie". Macros are important, and I still haven't got it totally figured out except I shoot for >20% from protein. I need to eat cleaner, and I need to treat processed foods and sodium as the devil. I have A LOT more to learn in the kitchen. But overall, I learned I couldn't out-exercise my eating habits, even if the calorie math made it really look like I could.
  • krysmuree
    krysmuree Posts: 326 Member
    edited January 2015
    Thank you for sharing, Swimgoddess. Great post. :)

    I definitely don't rely solely on my HRM and I certainly don't use it for Zumba class (kudos to you, I haven't tried one yet!) but I would certainly be suspicious of those kinds of burn numbers myself. When I lost 13lbs a couple of years ago, I was doing the 30 Day Shred, walking a steep nearby mountain weekly and eating extremely well and on target - HRM or not. My HRM helped keep me motivated and I only ate the calories I needed, never what I "earned" (i.e. if I'm still hungry, a carrot, or an apple - not a 400 calorie meal). That's probably why I did lose weight.

    But if you're eating all of those calories back and not actually having an accurate burn, I can see how frustrating that would be. :(
  • Hornsby
    Hornsby Posts: 10,322 Member
    KrissyMuree wrote: »
    I've consistently used my FT4 for strength training/cardio workouts for years and when I was using MFP before (I should add this is standard DVD ST & cardio, in addition to treadmill, outdoors running/jogging, hiking - not gym ST), I logged exactly what my HRM said and only ate the calories back if I was really hungry. I lost weight consistently. It might be for "steady state cardio" but I have used it for everything and have never had an issue losing weight when following it. I'm so surprised to hear others have had issues! :\

    Because you experienced a coincidence. Asking an HRM to be accurate for something it was NEVER designed for is like asking a calendar to tell you the time.

    What people need to remember is that an HRM is a training tool that tells you heart rate. That is the only thing it is designed to do. Everything else is an estimation based on numerous variables. One of those variables is that it assumes you are doing steady state cardio.

  • BusyRaeNOTBusty
    BusyRaeNOTBusty Posts: 7,166 Member
    Yup. HRM measure heart rate accurately. They then use certain equations to convert that heart rate to calories burned. These equations are just estimates. Different manufacturers use different equations actually. And they are only even close to accurate during steady state cardio exercise. They'll be WAY off for lifting, yoga, HIIT, etc.

    So what can you do? Use the numbers from the HRM for cardio, maybe round down a bit just in case. Use MFP's numbers for other activities. Measure and count calories accurately and see what happens for 3 or 4 weeks. If you do not lose, something is off, either your calories burned or the calories you are in-taking. Adjust either, see what happens for 3 or 4 weeks...
  • krysmuree
    krysmuree Posts: 326 Member
    That makes sense. :) What a huge bummer though. After having it for three years and using it on MFP for so long, it's amazing that I had never heard of this. Better late than never I guess. :p
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    edited January 2015
    It's all estimation which is what makes the MFP method difficult and cumbersome. In my experience it's best to go with the most conservative estimate when using the MFP method...after some time you should be able to see trends...if those trends are in line with expectations then carry on...if not, make adjustments as necessary.

    People get far too wrapped up in the gadgets and calculators and seem to forget that real world results are all that really matters...these tools simply provide a reasonably good starting point, but that's about it.
  • krysmuree
    krysmuree Posts: 326 Member
    edited January 2015
    What would be the best course of action, then? Logging what MFP suggests (or) logging what my HRM suggests, and not eating the calories back? Just following the guided daily caloric intake?
  • Hornsby
    Hornsby Posts: 10,322 Member
    edited January 2015
    A lot of people that lift or do exercises that fall outside of HRM parameters follow the TDEE method. Exercise isn't worth anything and calories consumed is based on your total activity including exercise. You do need to be somewhat consistent to follow this method in my opinion though.
  • IsMollyReallyHungry
    IsMollyReallyHungry Posts: 15,385 Member
    KrissyMuree wrote: »
    I've consistently used my FT4 for strength training/cardio workouts for years and when I was using MFP before (I should add this is standard DVD ST & cardio, in addition to treadmill, outdoors running/jogging, hiking - not gym ST), I logged exactly what my HRM said and only ate the calories back if I was really hungry. I lost weight consistently. It might be for "steady state cardio" but I have used it for everything and have never had an issue losing weight when following it. I'm so surprised to hear others have had issues! :\
    I agree with this statement, but I have heard many, including my trainer say you should not count calories from weight/strenght training.
  • IsMollyReallyHungry
    IsMollyReallyHungry Posts: 15,385 Member
    edited January 2015
    Right now I am using FitBit and hopefully it works like the BodyMedia things. I could not afford the higher price exercise toys. :smile: and I love it!! Because when I do not do enough exercise it takes away calories, which is good because I know to eat less so I break even. So far so good. I weigh daily and I lose something daily but that is also because I weigh over 300 pounds too. :(
  • krysmuree
    krysmuree Posts: 326 Member
    edited January 2015
    When following the TDEE, say my TDEE is 2,399 - I'd subtract 20%, which would be a total of 1,919, and eat that daily but not log exercise (or simply log but pretend those calories aren't there :p)? I consistently workout four days a week and since that is factored in ..
  • brandigyrl81
    brandigyrl81 Posts: 128 Member
    I, too, have a Polar FT4 and have not had issues with it and I use it for everything from dancing to weight training. I simply just log however many calories my FT4 says I burned under my own exercises, which I've created, and that's it. And I typically don't eat back my exercise calories. As someone else mentioned, I've lost weight just fine using this method. As long as you're accurately tracking all of your food, you shouldn't have any issues.
  • krysmuree
    krysmuree Posts: 326 Member
    brandigyrl81 - I think that's why it worked for me. I didn't eat the calories back, so I wasn't misguided into thinking I was able to justify eating all of this food or anything. I logged it to log it and keep track, and ate 1700 or so a day. It's probably more problematic for people that eat all of their exercise calories back. :/
  • ksy1969
    ksy1969 Posts: 700 Member
    I know logically why the HRM isn't accurate, but it doesn't matter. I lost over 100lbs by using a Polar FT4 to calculate my caloric burn. Didn't matter whether it was running, walking or lifting. Now, let me clarify, most days I did not eat all my exercise calories. In fact usually only about half, but there were days I did eat them all.
  • Hornsby
    Hornsby Posts: 10,322 Member
    brandigyrl81 wrote: »
    I, too, have a Polar FT4 and have not had issues with it and I use it for everything from dancing to weight training. I simply just log however many calories my FT4 says I burned under my own exercises, which I've created, and that's it. And I typically don't eat back my exercise calories. As someone else mentioned, I've lost weight just fine using this method. As long as you're accurately tracking all of your food, you shouldn't have any issues.
    ksy1969 wrote: »
    I know logically why the HRM isn't accurate, but it doesn't matter. I lost over 100lbs by using a Polar FT4 to calculate my caloric burn. Didn't matter whether it was running, walking or lifting. Now, let me clarify, most days I did not eat all my exercise calories. In fact usually only about half, but there were days I did eat them all.

    Think about what you both just said. You were using an HRM to calculate calories, but you weren't eating the calories back (or a portion). When you workout you obviously burn something so if you aren't eating them back, of course it looks like the HRM is accurate when in reality, it doesn't even need to be in the conversation for you all since you weren't eating the calories back to begin with.

  • brandigyrl81
    brandigyrl81 Posts: 128 Member
    Hornsby, I see what you're saying. I mainly just threw in my "I don't typically eat back my exercise calories" comment as a side note. My main point to the OP was to go ahead and log the calories burned from her Polar FT4 as opposed to MFP.
  • sola24
    sola24 Posts: 334 Member
    I typically do not eat back all my exercise calories all the time as I do not weigh my food as well. Sometimes I go over and sometimes under. I used to average out on a weekly basis. Now I am planning to average out on 80% of the calories as see where it takes me. I cannot do without eating exercise calories at all as I am pretty tiny and get only 1230 calories a day. I should look into the TDEE method as well and try to average out on that.
  • emmalynesmom
    emmalynesmom Posts: 3 Member
    I have a polar ft4 and I love it. I follow the calories it tells me. I eat most if the calories I am allow but concentrate on my macros. I don't get get enough protein for my muscles to recover but I have definitely improved. And I am losing weight. So it's all good.
  • sola24
    sola24 Posts: 334 Member
    I just did T25 Speed 2.0 and burnt 266 calories. It must be correct as it was purely cardio. Even if I chose high impact aerobics in MFP for 25 mins it does not show this much burn!

    P.S I am 5ft and 111-112lbs on most days
  • DeeTee68
    DeeTee68 Posts: 198 Member
    I have a Polar FT7 according to that I burnt:
    362 calories doing 30 mins of HIIT on the spin bike.
    However, according to my spin bike onboard computer which was also monitoring my heart rate, I burnt 882 calories.

    Now that is a hell of a difference. I am inclined to believe what the Polar is calculating, the figure seems about right for that amount of work and it was not far off what MFP said I had burnt for the same session.
  • sola24
    sola24 Posts: 334 Member
    For me though MFP gives me a lot less calories than my Polar FT4. I am trying the eating 50-80% of my exercise calories back method. Let me see how it goes.
  • Hornsby
    Hornsby Posts: 10,322 Member
    sola24 wrote: »
    For me though MFP gives me a lot less calories than my Polar FT4. I am trying the eating 50-80% of my exercise calories back method. Let me see how it goes.

    That's because HRMs can't track the activities you are doing accurately.

  • DeeTee68
    DeeTee68 Posts: 198 Member
    jaymeechick wrote: »
    I have a polar watch Ft4, and I always use it when working out. I like to see how my heart rate is throughout my workout and to see if it am "in the zone". I always just put the number of minutes into MFP and it is usually less. This way I know that I am 'under estimating' my calories burnt. It cant hurt. If you burned more then you will simply lose weight faster! :)

    Indeed well said
  • RachelSD7
    RachelSD7 Posts: 65 Member
    My polar FT4 just told me I was at 100% of my heart rate!
    I licked the strap (please, who doesn't) and then my heart rate stayed at a steady 150-160bpm.
    How do you know when it's accurate though? I suppose I bought the HRM to motivate me to work out more, which it's doing and I've lost 3lb so far, so I guess it does work in a backwards kind of way!
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    Confused...

    So when you started it told you that you were at 195 bpm, then you wet the strap and it came down to 150-160?

    For me, 195 is very hard work and I can only sustain that for about 400 metres at a time, but I can go at 150-160 for 3-4 hours or so.

    It's really just a question of what you want from your session.
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