Another view about eating back exercise calories

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Schmelvie
Schmelvie Posts: 233 Member
in Health and Weight Loss
This is a slightly different opinion about eating back exercise calories.

First of all, this is not a post about “whether or not” you should eat them back. I’ll let you decide that for yourself. I, personally, eat a percentage of mine back. Usually about 75% as a general goal.

This is purely about the numbers. As I started thinking about it, if I ate back all my exercise calories, it would actually put me OVER my daily net calorie goal. Here’s why.

My BMR is estimated to be 1,776 calories per day. So if I did absolutely nothing, my body burns 74 calories per hour on its own. Let’s assume I go work out for an hour, and my heart rate monitor says I burned 500 calories that hour. Well guess what, that’s only 426 more NET calories than I would have burned without the exercise.

Most people would just eat back the full amount… 500 calories. But what about the 74 calories you would have burned without the workout? You know, the ones that are already factored in to your MFP daily caloric calculations? It’s my opinion that they need to be subtracted out, since they are already factored in to your goals. If you counted the whole 500 calories, you’d basically be accounting for those 74 twice (once in your MFP daily calculations, and once from the exercise).

So for me, I need to subtract the 74 calories that I would have burned without the exercise. Instead of “eating back” 500 additional calories, I should only eat back 426 of those.

It might be a little convoluted how I present it. But this is my argument for only eating a portion of the exercise calories back.
And I also know it might be splitting hairs with regard to the numbers, but consider this:

If I work out 6 hours per week, times 52 weeks, times 74 calories per hour (if I was double counting per above argument), that’s 23,088 calories per year that I would have mistakenly eaten back. That’s 6.5 pounds!

Take it for what it's worth, but it's why I only eat a portion of mine back.

Replies

  • JuanaViviane
    JuanaViviane Posts: 20
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    I don't eat my exercise calories back..
    I eat my daily calories and then I exercise. :/
  • GeekyGoddess
    GeekyGoddess Posts: 119
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    I'm going to have to re-read that to be able to fully wrap my head around it but, like you, I can't justify in my head eating back caloried I burned on purpose. Although, I've yet to read a study that conclusively finds that exercising actually benefits weight loss...I've personally found that WL is 90% diet/nutrition and 10% exercise. I work out, because there are cardiovascular benefits, and I enjoy strength training and being strong, but for weight loss...thats not why I burn...
  • mwilliams1974
    mwilliams1974 Posts: 15
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    I know that when I've gone hard on a CV workout (mine is all aerobic no anaerobic) that I need to take back some of those calories burnt. I actually feel very hungry and a lack of food makes me feel pretty terrible the day afterwards. I like the idea of a rule of thumb (say 75%) as I don't tend to eat them all back - it just depends on how I feel how much I eat.

    Yesterday was a good example where I 'earned' 879 calories through a 10k run. I ate plenty but still had 375 calories 'left' over at the end of the day. As I didn't feel hungry for more I left it at that.

    I am still trying to shed a few pounds - I'm currently targeting another 7lbs - so in my mind my approach yesterday will support my weight loss goal. If I'd simply eaten back all the earned calories it would have felt a bit self-defeating.

    My weight loss is geared around getting fit (via increasing the CV intensity) and eating healthily (via the calorie control). It seems to be working.
  • Ghilber
    Ghilber Posts: 19 Member
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    I've thought the same thing.

    ie. Is the calories burnt during exercise the calories above BMR, or total calories burnt by the body during that hour.

    Then I thought, if that small amount of calories (ie. the BMR during my hour of exercise) matters, I probably eating too many calories.
  • geekyjock76
    geekyjock76 Posts: 2,720 Member
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    My BMR is estimated to be 1,776 calories per day. So if I did absolutely nothing, my body burns 74 calories per hour on its own. Let’s assume I go work out for an hour, and my heart rate monitor says I burned 500 calories that hour. Well guess what, that’s only 426 more NET calories than I would have burned without the exercise.
    Not to be picky, but you need to calculate using RMR, not BMR, in your above example as baseline. Resting Metabolic Rate is what you'd use if you got up and sat on the couch all day - BMR is the amount of energy needed while asleep or in a coma.

    RMR = 500 + (22 x lean body mass kg)

    Your predicted BMR is nearly identical to mine, so your predicted RMR would be around 1940.
  • chakslv
    chakslv Posts: 6 Member
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    Ok. I have wondered the same thing...leading to the theory of net calories. But I have another question. If you put an exercise factor into your MFP calculations, wouldn't that build in that anticipated amount of exercise and therefore, calorie needs. If so, when you add your hour (or five) of exercise, wouldn't you be double counting to some extent?
  • waldo56
    waldo56 Posts: 1,861 Member
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    You are way overcomplicating this.....

    You need either a static daily calorie goal, the TDEE method
    -or-
    A dynamic daily calorie goal that adjusts needs based on estimated burn, the MFP method

    If you add up all the calories you consume during the week, each method should give you the exact same results, and those results should give results almost exactly as predicted. If you set your goals for a daily deficit of 1000 cal, or 2 lb/wk, and hit those calorie goals on the dot, you should lose 2 lb (on average). If not you calorie goals need adjusting to reconcile results with projections.

    MFP was designed to use dynamic calorie goals (that is, it adjusts your goals to your daily activity level, you don't need fairly constant activity levels). If you are not "eating your exercise calories back" you are not using MFP correctly, all of the equations used to calculate you calorie goals that MFP uses are invalid; your goals have no bearing on results, you are merely trying to "lose weight" "safe" and probably have a way bigger deficit than you should, chances are you are going to be very prone to plateaus and stalls, are going to lose a lot of LBM, and will tank your metabolism over time.

    If you choose to not "eat your exercise calories back" it is by far in your best interest to switch to the TDEE method of calculating your calorie goals and setting custom calorie goals. You are using MFP incorrectly if you are using MFP's automatic calorie goals.

    If your results aren't in-line with what you expect based on your expected defict, instead of adjusting calorie counts of exercises or throwing out exercise calories altogether, adjust your calorie goals to reflect your actual observed deficit.
  • brownshuga30
    brownshuga30 Posts: 106 Member
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    This has always been a very confusing topic for me. I always hear to lose weight you need to burn more calories than you consume, so I don't understand why I would need to eat back the calories I burned exercising.
  • SurfyFriend
    SurfyFriend Posts: 362 Member
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    As I am not an expert I can only go by my own experience. during my 3 weeks using mfp I've noticed a trend. on the day of a very large burn i dont eat back many - if any of the exercise cals because i dont feel hungry. but over the next three days i intake is slightlyhigher an my appetite is increased. In one day i may not eat many back but over a week i generally hit my goal for net cals
  • omma_to_3
    omma_to_3 Posts: 3,265 Member
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    Subtracting your BMR calories is correct. I don't consider that eating only a portion of your exercise calories though. You're eating them all - you're just more accurate at recording them than others. I subtract my BMR/RMR calories as well.
  • katieheston
    katieheston Posts: 32
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    I think it is wise to err on the side of caution. But I've read that there are other factors that play into it besides just the percintile/ estimated calories burned at rest. If a person my size/weight did high impact cardio for, say, 30 minutes versus someone half my size/weight; would the amount of calories burned be the same? Assuming we invested the same amount of energy into the workout, it has been theorized that someone of larger girth actually burns more calories because they are carrying more weight, and carry more fat to burn (vs. muscle). A person half my size/ weight would have less weight to carry, and thus it is assumed would burn fewer calories as a result. Having said that, I've also read articles that state that people of "average to fit" weight burn fuel more efficiently. So I guess it could be argued that THEY burn more calories for the same level of work.

    Ultimately, for me, as long as I'm moving and coming in at the end of the day UNDER daily calories (NOT the adjusted calorie total after exercise), then I'll be healthy. At present, weight loss is a must for me. But once I get closer to the "average" weight range for my age and height, I'll be more concerned with quality of life performance over scale results. Everyone is different, y'know?

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