So how accurate are calories lost on exercise?

It depends how much you weight... An obese person doing about an hour of exercise can lose 500 cals pretty easily... But someone like me, at 140 pounds, i probably only burn about 150-200 (and thats kind of generous).

Most people follow a rule of eating back about 50%-75% of what MFP claims you burn. I personally eat about 1,300-1,500 cals a day and don't eat anything back. It's just not worth it, i don't burn as much as others anymore.

n1cholee93 wrote: »

It depends how much you weight... An obese person doing about an hour of exercise can lose 500 cals pretty easily... But someone like me, at 140 pounds, i probably only burn about 150-200 (and thats kind of generous).

Most people follow a rule of eating back about 50%-75% of what MFP claims you burn. I personally eat about 1,300-1,500 cals a day and don't eat anything back. It's just not worth it, i don't burn as much as others anymore.

I agree with the above, as a safety net only eat back 50-70% of the estimate from mfp. This covers observation bias, errors in MFP's calculation for some exercises and the fact it is never 100% accurate for any one person.

Use a heart rate monitor or ignore MFP exercise values.

Whatever MFP tells you, go for half.

n1cholee93 wrote: »

Someone who is in peak condition (in my opinion) riding their bike for an hour at 15* MHP to burn 500 calories and an obese person can do that in an hour. Well that's a mighty big difference? Maybe it takes less, i don't know, it's just what others have told me on here. I'd love to find a way to burn that kind of calories.

Burning 500 kCal per hour on a bike means you've put out an average of 138 watts.

Anybody with enough aerobic fitness to keep turning the pedals for an hour should be able to do that, and will find it somewhere from easy to moderate.

I never use MFP estimates. They are based on averages and often use "windows" for pace and such that allow error.

Much like @sijomial I find that the best thing to do it research and figure out what is reasonable for your size and exercise intensity. Though many here seem to have focus on being cautious towards weight loss, having poor estimates can just as easily mess people up in that respect as well.

Being that fitness level is often subjective with many types of exercise, I found that running/biking/cardo output measures are often a decent way to gauge workload and at least get people in the ballpark for other types of exercise. Heart rate monitors might help with some exercise types, but that varies as well.



Being that we can't gauge how hard another person is working without some type of speed or other measure, stating any basic rule to apply is tricky. If I only ate back 1/2 of my exercise calories that MFP suggests, my workout from yesterday would be skewed to me creating at deficit of almost 600 calories, since the MFP default is low for my fitness level on the elliptical machine I use, which has a better power measure. For the next person the estimate might be close. For a very fit or unfit person it would be farther off in either direction.


@misssamrogers For your size and that time frame, I would say 800 calories is more geared towards a higher fitness level than you seem to think you are at, but keep in mind that without a measure towards something easier to calculate, that can be hard to pin down. As an example if you knew for sure that your workout was at a higher cardio intensity than you say, running 5 MPH for an hour, you have a better gauge for comparison.

You can also often find MET value or perceived exertion charts, that when used with some online calculators, should give you at least a ballpark range of what is reasonable. The one below is based on studies and models for walking and running, but if you do either it might give you a comparison of sorts.

exrx.net/Calculators/WalkRunMETs.html