Tuesday, October 29, 2013

Exercise calories....

You want to start a war on an online weight loss and/or fitness forum?  Ask a question about whether or not you should "eat back" the calories that you burn through exercise.  What does that mean exactly?  It means that if you burn, say 300 calories through exercise in a day, should you ADD those to whatever calories you are consuming for weight loss.

So let's talk about this.  There are the hardliners that INSIST that you must eat back your calories for optimal performance and that you risk you calories being "way too low" if you don't eat them back.

Well I'm here to tell you - THEY ARE WRONG.  You should not consider strictly "eating back" the calories you burn through exercise.

First off, let's talk about how you are measuring the calories that you burned.  Are you using the machine's numbers?  Like on the elliptical or the treadmill?  Because if you are, you are WAYYYYYYY overestimating the number of calories that were burned.  Machines like ellipticals and treadmills are NOTORIOUS for totally overestimating the number of calories you burned.  For example last night I came home from work and used the elliptical for 50 minutes.  The elliptical numbers told me that in that 50 minutes that I burned 1,058 calories!  Yeah, right!  I WISH that were true.  

So if you are relying on those numbers,  and say you are on a 1500 calories per day diet and the machine tells you you burned 500 calories and you eat 2000 that day, but you REALLY only burned 250, then you just ate 1750 calories.

Ok, so how about online calculators?  Some of these are pretty good.  You can get a fairly accurate count on some of these.  Look for the ones that ask your current weight and sex to be the most accurate.  

But even then, there are a lot of factors that can go into how many calories you burn.  Like how muscular you are.  People with a large muscle mass burn MORE while working out then people with a lower muscle mass and higher fat.  Also your form is important.  As is the effort you are putting in.  For example, when I stayed at a hotel earlier this year, I went to the exercise room bright and early and got on the elliptical.  While I was busting my ass on that thing, I watched a woman who was on a recumbent exercise bike.  She was laid back haphazardly pedaling while reading a paperback book.  Now if she put into a calculator that she rode an exercise bike for 30 minutes, how would the calculator know that she was lazily pedaling versus someone who was going balls to the wall on the thing?  

So what is the closest you can get to accurately knowing how many calories you burned?  A watch with a heart rate monitor.  The ones with a chest strap are BY FAR the most accurate way to measure your heart rate and, in turn, calories burned.  That will give you a decent idea of what you are burning.  And I hate to tell you, but it's probably going to be lower than you would like to see.

Another thing that people don't consider when they are taking into account their exercise is their Basal Metabolic Rate.  Your BMR is the amount of calories you burn just by being alive.  So my BMR is about 1200 calories.  That's how much I would burn in a day if I laid in bed and did NOTHING.  That's 50 calories per hour.  So, for example, today I went out and ran at lunch.  My heart rate monitor tells me that I burned 595 calories on my run.  But automatically I have to deduct 50 from this because I would have burned that if I sat here at my desk and didn't move.  If I was even puttering around, that would probably burn an addictional 50 calories, right?  So really I only "burned" 495 calories.

See how this gets tricky?

So, the bottom line is that you should not be strictly eating back your calories.  With that being said, if you did a particularly hard and intense workout, you should not be afraid to eat a little more.  For example, I ran 17 miles on Sunday.  My heart rate monitor showed that I burned 1465 calories during that run which took me 2 hours and 23 minutes.  I ate about 400-500 calories more than normal that day to compensate.  But not 1400 more, FOR SURE.

The bottom line is that exercise is GREAT for you.  It will increase your fitness.  You will look better at the same weight as someone who doesn't work out.  You WILL burn calories.  But don't go for an hour walk and expect to come home and eat a pint of Ben and Jerry's and call it even.  No way.  You won't lose weight that way!



  1. Well said..don't know how many times I hear I walked to the P.O. today {3 blocks} So I earned the HOT FUDGE Brownie with Ice cream or Apple pie....{remember I am a waitress!

  2. I would have a hard time keeping my mouth shut!!!

  3. Yeah but OH those tips......I do love it when they say "you look like you never eat dessert" I don't anymore and that helps me to stay this way,occasionally a taste. " for NOW its good enough" Love those size 4s instead of 14s!!! They taste much better!