Exercise Calories - My Light Bulb Moment

lizblizz2012
lizblizz2012 Posts: 196 Member
in Fitness and Exercise
I know many of you are going to say "I already knew that, it's common knowledge, yada yada...." BUT for me it was an epiphany!

I have heard people say to only eat back no more than 50% of your exercise calories because MFP over estimates them, it's counter productive, etc. etc. But at work today it just CLICKED why you shouldn't eat back all of your calories. I'm just going to use approximate numbers in my examples.

Let's say MFP has calculated that your TDEE is 2000 and you want a 500 daily deficit. You're on the 1500 calorie plan. So MFP is saying that just from your normal activity, that is how many calories you will burn in a 24 hour period. So now let's say you burn 150 calories per hour walking around work at a slow pace, just doing your job. That's included in your TDEE. But today you got off work an hour early, yay! Why not go for a run? So you run at 5 mph for an hour and burn say 500 calories. So you log the 500 calories of exercise and you're thinking "Sweet, I can eat 500 extra calories and my net will still be the same!"

WRONG.

MFP & your TDEE already accounted for the fact that you burned 150 calories during that hour. Whether you were running for the hour or walking for the hour, an hour of time still passed. So you burned 350 extra calories because 150 of those calories would have been burned anyway had you been walking like your TDEE calculated for. So if you eat all 500 of those calories back, your net will actually jump by 150 calories because MFP assumes that those calories were burned IN ADDITION to the calories that it already accounted for in your TDEE.

Now don't get me wrong, there are days that I eat every last stinkin' on of my exercise calories (sometimes more...:ohwell:). But it's something to think about if for instance you've hit a plateau and are wondering how you can get things going again. Yes, your body needs more energy on days you exercise. But eating back all of your calories on a regular basis may be doing more damage than you think.....

Replies

  • kdzi
    kdzi Posts: 78 Member
    You've just discovered "net calories." You can subtract them (formally or informally) if you want. For instance, i know my (tested) BMR is 1572, which works out to be about 1.1 cal/minute on average. If I log a workout for 60 minutes, I subtract 66 (or you can mentally do this when deciding how many exercise cals to "eat back"). For short workouts, it hardly matters, but a 3 hour hike...it matters!
  • Yogi_Carl
    Yogi_Carl Posts: 1,906 Member
    I understand what you think you mean but with respect, I think you have it wrong.

    If your daily activity is factored into your TDEE calculation, your base 150 calories are already calculated into your exercise hour.

    So your exercise calories for that hour are all literally exercise calories because they are ON TOP OF your TDEE calories which are already factored into your default calculation.

    Having said that, it is only necessary to eat back your workout calories if you really are properly hungry. Leaving them uneaten can help your weight loss, so long as this does not lead to a blow-out.
  • lizblizz2012
    lizblizz2012 Posts: 196 Member
    I understand what you think you mean but with respect, I think you have it wrong.

    If your daily activity is factored into your TDEE calculation, your base 150 calories are already calculated into your exercise hour.

    So your exercise calories for that hour are all literally exercise calories because they are ON TOP OF your TDEE calories which are already factored into your default calculation.

    Having said that, it is only necessary to eat back your workout calories if you really are properly hungry. Leaving them uneaten can help your weight loss, so long as this does not lead to a blow-out.

    That depends on if the database has already accounted for TDEE calories. If it hasn't, then it's still right... because in any given hour you're guaranteed to burn 150, and if you burn 500 one hour, 150 of them are already factored in because you would have burned them had you been running or not.
  • jaz050465
    jaz050465 Posts: 3,508 Member
    There's also the fact that lots if people think MFP over estimates calories burnt in exercise.
  • Yogi_Carl
    Yogi_Carl Posts: 1,906 Member
    That depends on if the database has already accounted for TDEE calories. If it hasn't, then it's still right... because in any given hour you're guaranteed to burn 150, and if you burn 500 one hour, 150 of them are already factored in because you would have burned them had you been running or not.

    That is factored in when you enter your default settings at the beginning when you describe yourself as Sedentary, Light or Moderately Active etc - your daily calorie requirement per hour is part of your default. In that case your exercise calories are all exercise.

    Having said that, MFP does tend to eb generous with calories burned and I think most people only eat part or all of their calories back if they are genuinely hungry.
  • sapprjh
    sapprjh Posts: 1
    Runtastic consistently logs my cycling or running with a calorie burn rate at least 30% below the MFP estimate.
  • Flamencoflynnie
    Flamencoflynnie Posts: 61 Member
    This makes sense to me. I had never thought of eating back ANY of my exercise calories. No wonder I was always starving and ratty! On heavy exercise days (2 x 3 hours of flamenco per week) I'll have a little more (protein shake / oatcakes).

    Ahhh, now I can begin to be guilt free.

    Thanks for your lbm.
  • annams76
    annams76 Posts: 161 Member
    Thank you for your ephiany because you helped me out. I kept wondering about that and I never make it to what they say especially when I am working out. I feel so much better about my under calorie intake now. =)
  • neverstray
    neverstray Posts: 3,845 Member
    Yes. This is a fundamental flaw in the calculations. You need to subtract your TDEE amount during that time, and only add the true exercise calories. So, in your example, 350, not 500. But, I think that gets a little complicated, so just eating back a portion of your exercise calories is appropriate.
  • 00Melyanna00
    00Melyanna00 Posts: 221 Member
    Runtastic consistently logs my cycling or running with a calorie burn rate at least 30% below the MFP estimate.

    This is interesting, because Runtastic gives me values that are higher than those of MFP. And both values are higher than what the Kinrct Playfit app and my HRM say. (I trust the HRM more than any other tool).
  • takumaku
    takumaku Posts: 352 Member
    If I am interpreting your statement correctly, what you have discovered (i.e. the net calorie burn of walking vs running) was written in a fitness journal a while back. I believe the author of the publication was a local professor at ODU (Old Dominion University).

    As I remember the article, the old belief was, in relation to distance, walking and running burned the same amount of calories. This lend to the understanding that no matter which form of exercise you did (walking or running), the two exercises burned the same amount of calories as long as the distances were the same. The professor proved this belief was flawed. Now, it is understood that running burns more calories than walking when the distances are the same.
  • momar74
    momar74 Posts: 56 Member
    There is a number of ways to address: Keep your activity level @ sedentary and eat back all of your exercise cals (if you have entered goals into mfp then it should have built in the deficit already - suggest by C$4RL05), the other suggested by OP, eating a portion of exercise cals back.

    I do the first one, for me it is less complicated. I had this epiphany a few weeks ago. I was doing the insanity program and had my activity level as intermediate and ate back all of my calories, the scale did not move. I have a desk job, not a lof of additional activity. I was basically double counting. I changed my activity level to sedentary and contiued to eat back all of my exercise cals, the scale started to move again.

    Granted I should have figured this out a long time ago, but you live and you learn from smarter mfp posters.
  • neverstray
    neverstray Posts: 3,845 Member
    There is a number of ways to address: Keep your activity level @ sedentary and eat back all of your exercise cals (if you have entered goals into mfp then it should have built in the deficit already - suggest by C$4RL05), the other suggested by OP, eating a portion of exercise cals back.

    I do the first one, for me it is less complicated. I had this epiphany a few weeks ago. I was doing the insanity program and had my activity level as intermediate and ate back all of my calories, the scale did not move. I have a desk job, not a lof of additional activity. I was basically double counting. I changed my activity level to sedentary and contiued to eat back all of my exercise cals, the scale started to move again.

    Granted I should have figured this out a long time ago, but you live and you learn from smarter mfp posters.

    Even at sedentary, you have to account for the calories you would have burned doing nothing during your exercise. MFP doesn't calculate that. This is why you shouldn't eat ALL of your exercise calories. You can eat some or most or whatever, but should not eat them all because then you are effectively going over.

    So, if you burn 150 calories an hour doing absolutely nothing, maybe just sitting on the couch, then, you get up to exercise for 1 hour, and you burn 300 calories during your run, or whatever, then effectively, you should subtract the 150 calories that are already part of your steady state in that one hour, and so you only eat back 150. I know this is kind of complicated, but it is important. Otherwise, if you eat all of your exercise calories, you are eating 450 from 300 calories of exercise. Does that make sense?
  • Lady_Bane
    Lady_Bane Posts: 720 Member
    MFP over calculates the calories burned. I make my own workouts. I make it HALF of whatever MFP has.
  • Mokey41
    Mokey41 Posts: 5,769 Member
    If you're only exercising off a couple hundred calories a day there's really no need to eat them back. If you are genuinely starving hungry then you probably need to reassess your budget. A lifestyle change shouldn't involve the constant search for more food. I'm pretty sure the naturally thin (I use that term loosely) people don't spend all day thinking "Gee, if I walk to the mailbox I could earn a cookie!"
  • Yogi_Carl
    Yogi_Carl Posts: 1,906 Member
    There is a number of ways to address: Keep your activity level @ sedentary and eat back all of your exercise cals (if you have entered goals into mfp then it should have built in the deficit already - suggest by C$4RL05), the other suggested by OP, eating a portion of exercise cals back.

    I do the first one, for me it is less complicated. I had this epiphany a few weeks ago. I was doing the insanity program and had my activity level as intermediate and ate back all of my calories, the scale did not move. I have a desk job, not a lof of additional activity. I was basically double counting. I changed my activity level to sedentary and contiued to eat back all of my exercise cals, the scale started to move again.

    Granted I should have figured this out a long time ago, but you live and you learn from smarter mfp posters.

    Even at sedentary, you have to account for the calories you would have burned doing nothing during your exercise. MFP doesn't calculate that. This is why you shouldn't eat ALL of your exercise calories. You can eat some or most or whatever, but should not eat them all because then you are effectively going over.

    So, if you burn 150 calories an hour doing absolutely nothing, maybe just sitting on the couch, then, you get up to exercise for 1 hour, and you burn 300 calories during your run, or whatever, then effectively, you should subtract the 150 calories that are already part of your steady state in that one hour, and so you only eat back 150. I know this is kind of complicated, but it is important. Otherwise, if you eat all of your exercise calories, you are eating 450 from 300 calories of exercise. Does that make sense?

    But MFP already factors your daily calorie burn into your default settings - which is what you are doing when you answer the question for Sedentary, Light, Moderate etc. So if you deduct it from your exercise calories and it is already factored into your default settings you are effectively deducting base daily calories twice.

    Having said that, I tend to eat 50% of my workout calories back to boost weight loss, unless I feel I need to replace to the full - which holds off any feeding frenzy I may face days after if I am over-strict.
  • OnionMomma
    OnionMomma Posts: 938 Member
    Runtastic consistently logs my cycling or running with a calorie burn rate at least 30% below the MFP estimate.

    And that's why if you don't have a HRM you have to play with the amounts of food you can eat and still lose weight. I never eat back all of mine because if I did (since MFP over estimates) I would not lose anything.
  • neverstray
    neverstray Posts: 3,845 Member
    There is a number of ways to address: Keep your activity level @ sedentary and eat back all of your exercise cals (if you have entered goals into mfp then it should have built in the deficit already - suggest by C$4RL05), the other suggested by OP, eating a portion of exercise cals back.

    I do the first one, for me it is less complicated. I had this epiphany a few weeks ago. I was doing the insanity program and had my activity level as intermediate and ate back all of my calories, the scale did not move. I have a desk job, not a lof of additional activity. I was basically double counting. I changed my activity level to sedentary and contiued to eat back all of my exercise cals, the scale started to move again.

    Granted I should have figured this out a long time ago, but you live and you learn from smarter mfp posters.

    Even at sedentary, you have to account for the calories you would have burned doing nothing during your exercise. MFP doesn't calculate that. This is why you shouldn't eat ALL of your exercise calories. You can eat some or most or whatever, but should not eat them all because then you are effectively going over.

    So, if you burn 150 calories an hour doing absolutely nothing, maybe just sitting on the couch, then, you get up to exercise for 1 hour, and you burn 300 calories during your run, or whatever, then effectively, you should subtract the 150 calories that are already part of your steady state in that one hour, and so you only eat back 150. I know this is kind of complicated, but it is important. Otherwise, if you eat all of your exercise calories, you are eating 450 from 300 calories of exercise. Does that make sense?

    But MFP already factors your daily calorie burn into your default settings - which is what you are doing when you answer the question for Sedentary, Light, Moderate etc. So if you deduct it from your exercise calories and it is already factored into your default settings you are effectively deducting base daily calories twice.

    Having said that, I tend to eat 50% of my workout calories back to boost weight loss, unless I feel I need to replace to the full - which holds off any feeding frenzy I may face days after if I am over-strict.

    I don't believe what you are saying is true. You are double counting your exercise cals. So, if I sit in my chair and burn 100, or I go exercise and burn 300, the 100 I would have burnt is not accounted for in the 300. So, you would eat back 200. I know what you are saying, but I don't think that's right. I think it's an inherent flaw. And, probably a bit complicated to correct or calculate.

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