Confusion with Garmin and MFP Calories

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chrismason98
chrismason98 Posts: 6 Member
in Fitness and Exercise
Hi all,

New to the forums.
I've seen a number of discussions on the subject of the calories that Garmin sends to MFP, but I'm afraid I am still confused.

My situation:
I use a Garmin Forerunner 235 to monitor steps and running. I tend to wear it most of the day.
I have a desk-bound job, and perhaps walk 5000 to 8000 steps a day.
I run three times a walk, and when I do that I used a chest strap for accurate zone monitoring. That is typically 30 minutes each time (I'm starting out).

I use MFP to monitor my calories, partly out of interest, but also to help shed a few pounds.
I have MFP set to the lowest activity, and I have negative calorie adjustments turned on.

(by the way, does it make any difference if you set exercise goals in MFP, e.g. 3 times a week for 30 minutes - does MFP factor that into any calculations?)

On to today.

I have a daily calorie goal of about 1700 plus any exercise.
Today I did an interval run for 35 minutes, which according to Garmin burned 291 calories. Fair enough, and so it shows in MFP.

Then during the day, MFP shows me that Garmin is saying I've also done 7000 steps, burning an additional 1007 calories for a total of 1298! What?! Many of those steps were done during my run, and I can't see how it is possible that I could burn over 1000 calories walking 6000 steps anyway.

So, MFP by the evening tells me I have over 1000 extra calories I need to consume to meet my daily goal.

That cannot be correct.

Can anyone explain what is going on?

TIA
Chris.

Replies

  • PeachyPlum
    PeachyPlum Posts: 1,243 Member
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    Are you syncing your Garmin with any other apps? Strava, NRC, anything like that?
  • chrismason98
    chrismason98 Posts: 6 Member
    edited July 2019
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    PeachyPlum wrote: »
    Are you syncing your Garmin with any other apps? Strava, NRC, anything like that?

    No, just MFP.

    edit: I just realised I had Garmin Connect still synced with FinalSurge - would that make a difference?
  • heybales
    heybales Posts: 18,842 Member
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    The MFP Exercise Goals has no bearing on math for anything.

    You are typical desk job - not Sedentary with that step count. Around 4K you start coming out of MFP's definition of Sedentary, and moving on up to Lightly-Active and beyond.
    But can be left at Sedentary just fine - you'll learn the typical adjustment amounts for daily planning.

    So if set to MFP Sedentary - merely from daily activity you'll be getting adjustments higher.

    Throw in workouts and maintain that activity level - higher still.

    The extra calories does NOT come from the steps - but merely the Garmin Total Daily burned minus the MFP estimated daily burn and workouts it knows about.

    It could easily be correct with the workout included.

    The only kicker is the daily activity calories are based on distance and time - so that's where steps has a bearing.
    If the stride length is set wrong, you may not be going the distance it thinks, and not the calories it thinks.

    Ever walked a known distance (not GPS) of 1/2 to 1 mile on like high school track (confirm the markers for miles not metric), and compared what the tracker thought you did?
    Should be at about 2 mph pace (can use GPS for that estimate), that way it can dynamically adjust down to grocery store shuffle, or up to exercise pace.

    If you click on the Garmin Adjustment entry for more details - you'll see the time stamp specifics and calorie count at that point - you can confirm.

    If you like math and want to see specifically what's happening - read the 2nd section here.
    It's about Fitbit which doesn't send workouts to MFP - but I reference what happens with workouts so that part applies. The methods use still apply.

    http://community.myfitnesspal.com/en/discussion/10098937/faq-syncing-logging-food-exercise-calorie-adjustments-activity-levels-accuracy/p1


    That much adjustment for a workout and above Sedentary besides could easily be 1000 extra - depending on the distance of the daily steps.

    You can include screen shot of that details screen for the Adjustment.
  • chrismason98
    chrismason98 Posts: 6 Member
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    heybales, this is very helpful stuff, thank you.
    I'll take a closer look tomorrow, when hopefully I can read and think at the same time!
    I did do a stride length test, 540 metres and 640 steps, and came up with .91. I'm 6ft2. I could set my Garmin 235 back to auto. I think .91is pretty reasonable though.
  • heybales
    heybales Posts: 18,842 Member
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    You just want it set to middle of the road pace so it can dynamically adjust both ways.
    Set to exercise pace, the likely vast majority of your day no where near that pace can easily result in inflated distance. If very few steps, no big whoop. If a lot, big calorie error.

    If set to grocery store shuffle, and you do a lot of exercise pace walking, it'll underestimate the distance for less calorie burn.
    Probably want a good 2km walk at that middle pace to get stride length best.
  • chrismason98
    chrismason98 Posts: 6 Member
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    heybales wrote: »
    You just want it set to middle of the road pace so it can dynamically adjust both ways.
    Set to exercise pace, the likely vast majority of your day no where near that pace can easily result in inflated distance. If very few steps, no big whoop. If a lot, big calorie error.

    If set to grocery store shuffle, and you do a lot of exercise pace walking, it'll underestimate the distance for less calorie burn.
    Probably want a good 2km walk at that middle pace to get stride length best.

    I'll set it back to 'auto' just to see if that makes a difference, and update when I see any results
  • chrismason98
    chrismason98 Posts: 6 Member
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    @heybales, ok I've been through your post and the section section in the link you provided - excellent stuff.
    I have changed my MFP exersise setting one level up from sedantry. That has added 200 calories to my goal calorie intake for the day, unsurprisingly, but I think may be more in line with reality.

    Additionally, as above, I've changed stride length to 'auto' and lets see how that plays out.

    Now, I still have some issues with what Garmin is reporting, and Garmin Connect doesn't give you enough insight into it's summary data, compared to what MFP is doing.

    Take today for example - typical work day at the office. I try to make sure I get up and move around every 30 mins to an hour. I went for a 2.5 mile walk at lunch time, walking at 4mph average (the HR monitor on the watch was in use, not my HR band).

    What I see in MFP (at 8pm) is:
    - Walking, 4.0mph, 43 minutes : 200 calories
    - Garmin Connect Calorie Adjustment 7042 steps : 50 calories

    Total of 250 extra calories I can eat today.


    Compare this to yesterday (data as at 11.59pm, I guess when Garmin did a final update):
    - Running, 32 minutes : 291 calories
    - Garmin Connect Calorie Adjustment 7887 steps : 1213 calories

    I just can't reconcile those two. The only difference between today and yesterday is that today I went for a walk instead of a run. Somehow, the 7k steps yesterday were worth 1213 calories, but today's 7k steps were only worth 50 calories.

    I ended up yesterday with 1168 calories left to eat!

    I check in Garmin Connect, and as far as I can tell, the vast majority of the 7k steps from yesterday happened during my run - so how is this not double (treble and more!) counting?

    I feel I'm missing something here, that I'm not understanding, despite your excellent explanations!

  • heybales
    heybales Posts: 18,842 Member
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    That Adjustment line has more details that enables getting a full story. Have to tap hold on the line on mobile app to see it.

    Get those figures for those 2 days, and confirm the daily burn matches what Garmin said it was.

    Could have had a sync that didn't occur.

    The distance with those steps yesterday could have been totally hosed up on Garmin's side prior to sending anything to MFP to do math with.

    You'll find on that detail screen why it's not double counting if everything was sent correctly.

    Because whatever workouts MFP knows about - manually entered or synced - are assumed to be already contained within the Daily Calorie burn figure sent by the tracker - so they are subtracted prior to the the daily projection calculation.

    Like if Garmin said 1300 cal burn at noon
    and MFP estimated 1200 cal burn noon until midnight (from 2400 daily) - that would be 2500 daily burn projected.
    2500 - 2400 estimated MFP alone would be extra 100 calories to eat.

    But if there is workout on MFP within that 1300 of say 200 calories:
    Projected with Garmin 2500 - 2400 MFP estimated - 200 workout = neg 100

    But your eating goal is
    base + adjustment -100 + 200 workout = 100 extra to eat.

    Only kickers here are if a manually entered workout doesn't make it back to the tracker to increase it's daily burn.
    But that causes adjustment the other direction.
    Even if a tracker sync failed to get a workout to MFP - still a correct adjustment.

    The nomal failure points don't actually allow for an increase going the wrong way.

    Unless MFP has a workout but doesn't really subtract it in the Adjustment math, but does add it to the eating goal.
  • chrismason98
    chrismason98 Posts: 6 Member
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    Thanks for all the help. Today's numbers seem to make more sense. Hopefully that will continue...

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