Inaccuracies when using MFP for exercise

Lrdoflamancha
Lrdoflamancha Posts: 1,280 Member
in Fitness and Exercise
I have made a test of the accuracy of MFP to record calories burned during exercise. Today I rode a bicycle 98 minutes at 7.27 MPH. According to MFP my calories burned was 707. I then checked my Polar FT7 HRM. It showed 1042 calories burned. Then I checked that to Map My Ride it showed 1114 calories burned. Finally I checked my Fitbit it showed .... well I am not sure what it showed.
MFP >10 MPH 707
MFP 10-12 MPH 1061
Polar HRM 1042
Map My Ride 1114
Fitbit maybe 1007
I am going to go with the HRM recording. But I am concerned that if you are using MFP as your only way to track calories burned then if presented with 2 possibilities, it is best to take the lower one and then only eat half of your calories burned. I adjusted the MFP total to reflect the HRM total.

Replies

  • diligentjosh
    diligentjosh Posts: 274
    It all depends on body type, but I would say that your machines are a bit inaccurate, to the plus side. I just cycled for over 1 hour, at an average of 17 mph, and used my meter to measure 825 (mfp had it at about 1200 burned). I always go with my cyclometer on my bike (BELL brand, 15 bucks at Target). Even then, judgment is used, as the meter cannot detect hills and pedal speed.
  • diligentjosh
    diligentjosh Posts: 274
    I have confirmed the cyclometer to be accurate (+ / - 100) by a few sources. So I would look into that. 7 mph is relatively slow, and not much effort is needed, commonly. So I find it hard to believe you lost 1000 calories. But I could be wrong....age/weight play a factor
  • pixietoes
    pixietoes Posts: 1,591 Member
    I trust my HRM more than what I find on MFP which is information based on other people. I use the MFP info if I forgot to wear my HRM and can't find a similar workout in my past to use instead.
  • Lrdoflamancha
    Lrdoflamancha Posts: 1,280 Member
    I have confirmed the cyclometer to be accurate (+ / - 100) by a few sources. So I would look into that. 7 mph is relatively slow, and not much effort is needed, commonly. So I find it hard to believe you lost 1000 calories. But I could be wrong....age/weight play a factor

    AGE 62
    WEIGHT 236
    Route was 11.4 miles 7 miles up hill with a 20 MPH head wind.
  • needamulligan
    needamulligan Posts: 558 Member
    My tests have shown that MFP tells me I burned far more than my HRM! So, I have been overestimating my calories burned! I'm going with my HRM!
  • diligentjosh
    diligentjosh Posts: 274
    I have confirmed the cyclometer to be accurate (+ / - 100) by a few sources. So I would look into that. 7 mph is relatively slow, and not much effort is needed, commonly. So I find it hard to believe you lost 1000 calories. But I could be wrong....age/weight play a factor

    AGE 62
    WEIGHT 236
    Route was 11.4 miles 7 miles up hill with a 20 MPH head wind.

    lol.....yeah, resistance also is a big part of it...seems pretty accurate to me, then! Of course, it also depends on what you are hauling up the hill.
  • SyllyThings
    SyllyThings Posts: 15 Member
    There is a difference between gross and net calories burned. This link explains it well. I think MFP uses net and exercise equipment use gross.
    http://www.shapesense.com/fitness-exercise/articles/net-versus-gross-calorie-burn.aspx
  • iamnotjerry
    iamnotjerry Posts: 17 Member
    I have made a test of the accuracy of MFP to record calories burned during exercise. Today I rode a bicycle 98 minutes at 7.27 MPH. According to MFP my calories burned was 707. I then checked my Polar FT7 HRM. It showed 1042 calories burned. Then I checked that to Map My Ride it showed 1114 calories burned. Finally I checked my Fitbit it showed .... well I am not sure what it showed.
    MFP >10 MPH 707
    MFP 10-12 MPH 1061
    Polar HRM 1042
    Map My Ride 1114
    Fitbit maybe 1007
    I am going to go with the HRM recording. But I am concerned that if you are using MFP as your only way to track calories burned then if presented with 2 possibilities, it is best to take the lower one and then only eat half of your calories burned. I adjusted the MFP total to reflect the HRM total.

    Appreciate your efforts today. However, I remain confused as to what Fitbit states on MFP as opposed to the FB site.
    For me I will continue to log my exercise routine as best I can on MFP and monitor the info from FB site.

    I do not add a lot of calories that I need to burn, even at week's end. In fact I am usually way under according to what I eat, which is very low in calories. At this point I loose weight at least every other day if not everyday I drop a little. I will have to get a better take on the use of my Fitbit.
    Thanks
  • Lrdoflamancha
    Lrdoflamancha Posts: 1,280 Member
    There is a difference between gross and net calories burned. This link explains it well. I think MFP uses net and exercise equipment use gross.
    http://www.shapesense.com/fitness-exercise/articles/net-versus-gross-calorie-burn.aspx

    This is an excellent explanation. But how do you know which equipment tells you gross or net calories? . For instance does MFP report gross or net calories? How about my Polar FT7 HRM? I guess that until we know that we will have to guess. This is one of the reasons that I suggest that you only consume 1/2 of your exercise calories.

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