"Eat back half your exercise calories"

CattOfTheGarage
CattOfTheGarage Posts: 2,750 Member
edited July 2016 in Health and Weight Loss
I see a lot of people saying "eat back half your exercise calories" or "eat back a third" or whatever. Am I the only one who thinks this is a super complicated way to approach things? Seems like it would involve a lot of mental arithmetic at the moment of deciding whether to eat something or not.

If I'm worried mfp might overestimate exercise calories, I just enter fewer minutes - so maybe I walked for 20min but I'll only enter 15. That way I can still just look at the calories remaining and know whether to eat the thing or not. No on the spot mathematical gymnastics.

Anyone else? When you say "I only eat half my exercise calories", what do you mean? Do you enter half the minutes or are you always juggling the numbers from your latest workout in your head? I feel it could be helpful to get this clarified, especially for beginners.

And a related question: what is your basis for thinking mfp overestimates burn (as opposed to users overestimating intensity or length of workout)? I've seen a lot of people say it but I don't know what they're basing it on. Fitbit readings? Experience with slower than expected loss? Personally if I under-log exercise it's because I reckon I overestimate intensity or time - my own experience has not pointed to any issue with mfp's numbers for exercise. But then I eyeball my food, so I can't use my results as scientific evidence of anything.
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Replies

  • _sacar
    _sacar Posts: 80 Member
    Huh, I have always been told you shouldn't eat back your exercise calories at all. Shows what I know, lol.
  • CattOfTheGarage
    CattOfTheGarage Posts: 2,750 Member
    edited July 2016
    But if you've done several bits of exercise during the day and logged them in full, you're going to have to remember how many calories to leave uneaten at the end of the day. So if I burned 100cal walking and 50 gardening and 150 at the gym and 75 cycling to the shops, and I log all that in full but only intend to eat half of them back, I have to be carrying in my head that I have to leave my calories in the green by 183 at the end of the day, and then if I log another 50 calories I have to remember to leave 208 uneaten now, and it just seems very complicated to me.
  • jemhh
    jemhh Posts: 14,262 Member
    Maybe a package of post-its would help. Or you could write it on your hand. Whatever works for you.
  • jkal1979
    jkal1979 Posts: 1,896 Member
    _sacar wrote: »
    Huh, I have always been told you shouldn't eat back your exercise calories at all. Shows what I know, lol.

    When it comes to the formula that MFP uses, you are supposed to eat them back (or at least a portion of them). There are other formulas that people use like the TDEE method where people don't add in their exercise calories since they are already added to the calorie goal.
  • CattOfTheGarage
    CattOfTheGarage Posts: 2,750 Member
    edited July 2016
    _sacar wrote: »
    Huh, I have always been told you shouldn't eat back your exercise calories at all. Shows what I know, lol.

    Depends if you are using mfp's calorie allowances, which are low to allow for counting exercise, and then you need to count it to avoid undereating; or if you are using a TDEE estimate from elsewhere which includes all your activity, in which case, no, you shouldn't count them. That's my understanding anyway.
  • RGv2
    RGv2 Posts: 5,789 Member
    But if you've done several bits of exercise during the day and logged them in full, you're going to have to remember how many calories to leave uneaten at the end of the day. So if I burned 100cal walking and 50 gardening and 150 at the gym and 75 cycling to the shops, and I log all that in full but only intend to eat half of them back, I have to be carrying in my head that I have to leave my calories in the green by 183 at the end of the day, and then if I log another 50 calories I have to remember to leave 208 uneaten now, and it just seems very complicated to me.

    If you know what your baseline is (let's say 1500), I don't see how it's hard to eat back 1/2 your exercise cals.....

    The reason that some log all of their exercisese is that they're tracking time, mileadge, etc... For me, I didn't so I used to enter about 60% of what I do (since I'm not tracking mileage). With my Fitbit now, I do eat back closer to 100%
  • _sacar
    _sacar Posts: 80 Member
    jkal1979 wrote: »
    _sacar wrote: »
    Huh, I have always been told you shouldn't eat back your exercise calories at all. Shows what I know, lol.

    When it comes to the formula that MFP uses, you are supposed to eat them back (or at least a portion of them). There are other formulas that people use like the TDEE method where people don't add in their exercise calories since they are already added to the calorie goal.

    Oh, you're right. I guess I'm doing a weird mishmash of the two - tracking with MFP but using the TDEE method of not eating them back. Oh well! You learn something new every day.
  • bendis2007
    bendis2007 Posts: 82 Member
    Here is a study out of Ball State. They took 6 of the top fitness trackers and measured them against oxygen consumption (one of the most accurate ways to measure true calories burned). They were all over-estimating calories burned as much as 122%.

    http://www.wthr.com/story/31285468/sometimes-your-fitness-tracker-lies-a-lot-fitbit-jawbone-garmin-ifit-misfit-accuracy

    As a rule for me, I always log my workouts but it's because I like to see that I get in exercise 5 days a week. You can of course put your workouts in the "notes" section of the diary so that it doesn't enter the calories into your daily calorie total. I make it a rule to try and never eat my exercise calories back. If you do eat them back, I would recommend eating less than half back as this study indicates there is a gross over-estimation. I also set my calories at a sedentary lifestyle. It's taken some getting used to but when I measure my food and eat my daily calorie allowance maybe eating back about 25% of the exercise calories, I do show 1-2 pound weight loss each week. It does work, it just sucks because even with trackers and technology it's very hard to know accurately how many calories YOU burn when you do certain activities and factor that in with eating.

    If you set your parameters on MFP, you should know about how many calories you want to consume each day and follow that relatively easy without looking at the overall "Net calories" at the top once you've input your workouts. Use your stats and to find your resting basal metabolic rate. From there you would multiply by 1.2 if mildly active or more if you are very active. That will give you a pretty good estimation of what you need to eat to maintain so eating less than that should help you to see the number on the scale go down.

    To answer your final question - aside from the study (which I'm sure has it's own shortcomings but is a good baseline for highlighting the errors with some of these trackers) just from being on MFP and the amount of people who note that they are eating 1200 calories, working out an hour everyday burning upwards of 4500 calories or more per day (highly unlikely) and yet show NO change in their weight it makes me think that they are either under-estimating what they eat, or they go off the tracker and over-estimate how many calories they actually burn during a workout and mistakenly eat too much to allow for any weight loss.
  • NorthCascades
    NorthCascades Posts: 10,970 Member
    edited July 2016
    And a related question: what is your basis for thinking mfp overestimates burn (as opposed to users overestimating intensity or length of workout)?

    I have a power meter on my bike which measures the amount of mechanical work I do on each ride. It's very easy and accurate (up to about 5% error) to convert kiloJules of work done into kiloCalories of energy required to perform that work. This is a set of pedals that cost $1,300 on sale. When I enter the information MFP wants about a ride I've done, it's usually in the ballpark of 2x too high.

    I don't have MFP estimate calories for any exercise I do, so I can't comment on the "mental gymnastics" angle. I have a Garmin watch (Fenix 3 HR) and trust it to do a good job of this, then it feeds the numbers into MFP.
  • Ready2Rock206
    Ready2Rock206 Posts: 9,488 Member
    But if you've done several bits of exercise during the day and logged them in full, you're going to have to remember how many calories to leave uneaten at the end of the day. So if I burned 100cal walking and 50 gardening and 150 at the gym and 75 cycling to the shops, and I log all that in full but only intend to eat half of them back, I have to be carrying in my head that I have to leave my calories in the green by 183 at the end of the day, and then if I log another 50 calories I have to remember to leave 208 uneaten now, and it just seems very complicated to me.

    Two things - 1) I'm not logging every single time I get out of my chair during the day and 2) so when you log it and it says 100 calories -just change it to 50 right there. Nothing to remember later.
  • Sued0nim
    Sued0nim Posts: 17,456 Member
    Burn 200 calories, log it as 100... Easy enough to double click on the calories and amend them

    I fail to see the problem
  • Jruzer
    Jruzer Posts: 3,501 Member
    WinoGelato wrote: »
    I always found the MFP estimates to be accurate enough for me for the exercise I typically do: walking and circuit training mostly. When I use a machine like the stationary bike, I often knock it down by about 20% when I log it, and hiking I often just log a shorter time period (usually about 1/3) and go with that estimate, figuring that about covers the amount of time I'm standing still pleading with my kids to just please stop complaining and get moving...

    Agreed. I just try to get as good an estimate as I can, and I then eat 100% of my exercise calories.
  • xmarye
    xmarye Posts: 385 Member
    Well, I would not eat my calories back since I think it defeats the purpose of using exercise as a tool to increase caloric deficit - but who am I to dictate this approach to everyone? I would still advise eating half rather then eating back all of them, just in case that there would be an overestimation... let's not forget that the goal here is to maintain a deficit! This is one reason why I am planning to get a fitness watch ASAP to help me understand my body better :)

    Also... I prefer to enter as my calorie goal my TDEE since that way I see the calories needed to maintain. The calories left (the green number) then represents my deficit, which motivates me a lot more. I think it makes more sense and helps me understand my body better; just make sure your recalculate your TDEE for every 5lbs lost and also be sure to have a sensible tool to calculate your body fat % to ensure best possible accuracy. P.S. I also take my measurements!

    All in all, just make sure that whatever you're doing is working and that you're losing on the scale! It's all about making it work for you. We can all share our experiences and motivate each other no matter what. I'm sure there are people that don't eat them back, some people that eat them all back or only half back, and all of those people could still lose weight!