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Net calories and big workout burn days

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Okay, this is probably a dumb Q, but I need your help.

I'm 5'11, 41 and female. Current goal is maintaining (sort of a slow recomp) 147 or so. My BMR is ~1450. My TDEE on a non-workout day is 1850-2000. The thing is, I do intense/high burn workouts at least 6 days a week. So for example yesterday, I hit 23,000 steps, did a hardcore workout and my charge HR Fitbit gave me a TDEE burn for that day of ~2900.

There are many days I net 1300-1500, and feel great.

What should I be netting on that 2900 day, or on any workout day?

Should I net 1457, my BMR? Should I net 1850-2000, which is my daily NON-workout TDEE?

(I originally tried a flat TDEE approach, but not all of my big burn days hit 2900. 2500 is more typical, but it does vary. It will drop in fall/winter, too. Hence, I prefer a net calorie approach.... I just need to know what number to shoot for!)

Tips? Guidance?

Thanks in advance.

Replies

  • Francl27
    Francl27 Posts: 26,371 Member
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    I'm honestly confused about what the difference would be with net or TDEE in this case. Why not just eat whatever your fitbit tells you each day? It would be basically the same thing.
  • _piaffe
    _piaffe Posts: 163 Member
    edited August 2016
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    The MFP net number is very different. Maybe that's why I'm confused?

    Edit: yesterday I burned 2900, ate 3195 and MFP says my "net calories" for the day are 2063. I am more confused than ever!
  • Nikion901
    Nikion901 Posts: 2,467 Member
    edited August 2016
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    _piaffe wrote: »
    The MFP net number is very different. Maybe that's why I'm confused?

    Edit: yesterday I burned 2900, ate 3195 and MFP says my "net calories" for the day are 2063. I am more confused than ever!

    So .... it appears that the definition of 'net calories' may the issue here, or that the burn calories are coming from a different source than the MFP exercise and goal calories you set up innitially.

    A couple or articles that might solve your mystery ...

    https://myfitnesspal.desk.com/customer/portal/articles/1027478-why-do-my-daily-nutrient-values-and-my-calorie-goal-change-when-i-log-exercise-

    https://myfitnesspal.desk.com/customer/en/portal/articles/12031-what-are-net-calories-

    https://myfitnesspal.desk.com/customer/en/portal/articles/410332-how-does-myfitnesspal-calculate-my-initial-goals

    and this one ...
    https://myfitnesspal.desk.com/customer/portal/questions/15898482-net-calories-confusion-

    ... which sounds like the same problem you are experiencing but doesn't really answer the question of why there is a difference between what you calculate and what MFP says it is.

    Maybe tracking your weight will help you determine how much of your extra exercise calories you should be eating back. If you are losing weight and don't want to, increase the intake or decrease the expenditure?

    If it were me, I'd drop about 10% off what my burn is and target that to maintain.


    PS --- I kept looking at the help pages and found this article ...
    https://myfitnesspal.desk.com/customer/portal/questions/16656594-net-calories-calculation

    Seems there is a bug in the calculation. ... or maybe it's fixed now ... at any rate, thanks for having an open diary, because I took a look at it to try figure out what you are seeing ... and it all looks correctly calculated on MFP ... so now the question I have is what are your getting your numbers from, MFP or your fitbit?




  • PAV8888
    PAV8888 Posts: 13,987 Member
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    Your answer depends on your goals.

    People who eat at "moderate" deficits would almost always eat above BMR.

    MFP assigns BMR 1.25 to sedentary, BMR x 1.4 to lightly active, BMR x 1.6 to active and BMR x 1.8 to highly active. It then adds exercise activity when you declare such on top.

    As you can see, eating at BMR creates at least a 20% deficit off TDEE (1.25BMR - 20% = 1)

    Given that a moderate deficit would be up to 20% (25% if obese)... most people who eat at a moderate deficit by definition eat above BMR, hence my original comment.

    Now we get into your various other calculations.

    Fitbit and MFP have a nice integration going where essentially MFP offloads the TDEE calculation to Fitbit.

    So, if MFP think that today you will spend 2000 calories.. it checks with Fitbit and if Fitbit is indicating you're on pace to spend more you get a positive adjustment. Else you get a negative one.

    The final accounting reconciliation happens at the end of the day and MFP and Fitbit compare which of them thinks you spent more calories and by how much.

    If Fitbit thinks you spent more calories you get a positive "exercise" adjustment on top of everything else you've logged through MFP.

    If Fitbit thinks you've spent less than MFP did you get a negative "exercise adjustment instead.

    In all this your NET caloric goal has not been touched!!! Why? Because in fact these positive and negative adjustments are precisely the mechanism that has been implemented to guide you to achieving your net caloric goal!

    Your net caloric goal is based on the MFP activity setting you've declared and the deficit/overage/maintenance goal you told MFP you had.

    About the "only" time this can go wrong is: :smile:
    When integration is broken
    When you declare yourself to be more active than you really are AND you do not have negative calories enabled (result: you will eat more than you should based on your actual activity)
    When your gadget is not estimating your caloric burns correctly and
    When your logging is not very accurate or consistent which means your intake is not correctly calculated :smile:

    Which leads us to the solution: monitor what your body weight trend does and adjust based on how closely your logging corresponds to your actual results.

    You can use your own spreadsheet to do that... or you can play with the one below: https://docs.google.com/spreadsheets/d/1VDmqNpLPu7sbQSochUJNXdp2F7AN15AGgkvS3zLw1GU/edit?usp=sharing
  • nxd10
    nxd10 Posts: 4,570 Member
    edited August 2016
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    I'm your height and weight and I net 1300-1400. But I'm 56. I've maintained 4 years. I used to use a fitbit and now use an apple watch to measure my exercise and just go with that. I have them synched with MFP so that it automatically adds my exercise into my diary. You have to make sure you have done that correctly or it will not calculate your calories correctly and your net will be wrong. Could that be the issue?

    If you start losing add some more calories in. This is all just a model. You are living the real world. We're all a little different. That's both our biology but also our style of logging and the accuracy of our exercise measurement.
  • _piaffe
    _piaffe Posts: 163 Member
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    Thanks for the links and the detailed explanation (which I've had to read a couple of times and am not sure I in fact fully understand!).

    nxd10, I think I understand your numbers and figured out my mistake: I fiddled with my settings and realized I'd manually overriden my "goals" calorie objective, because it had originally given me 1290 net for 1/week loss, and something like 1540 for 0.5/ week. I thought both of these were totally unrealistic for me, but I didn't understand that those were NET calories (not gross).

    I've reset my goals, so now it makes sense - I will follow MFP's suggested net numbers, and they add up.

    1790 NET for me to maintain 148
    1540 NET for 0.5/week loss
    1290 NET for 1/week loss
  • lemonychild
    lemonychild Posts: 654 Member
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    plus logging all your fitness calories eating them back.
  • TavistockToad
    TavistockToad Posts: 35,719 Member
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    Pick either MFP'S method or tdee, and stick to one for 4-6 weeks to see if you're eating enough to maintain
  • _piaffe
    _piaffe Posts: 163 Member
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    plus logging all your fitness calories eating them back.

    Oh yes, counting on the adjustment... I routinely get 800+ by way of fitbit Charge HR adjustments and have 1000+ weekend days!

    I'm not much of an MFP logger for exercise, however. I find their estimates off. The HR has seemed more "accurate" (and is lower than the gym machines), to the extent there is any accuracy at all.

  • _piaffe
    _piaffe Posts: 163 Member
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    Pick either MFP'S method or tdee, and stick to one for 4-6 weeks to see if you're eating enough to maintain

    I definitely need to give it a solid month. One thing I find with maintenance... I keep wanting to make a tweak, which means I am not getting the data I need to evaluate anything.

    New goal for maintenance: sticking to a period of maintenance where I don't change anything!
  • nxd10
    nxd10 Posts: 4,570 Member
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    This sounds like a good plan. I think a lot of people on this site confuse 'calories' 'net calories' and 'eating calories'.