MFP Exercise Calorie Estimates Methodology?

BrewerGeorge

Let me first apologize because this topic has been covered pretty well in the past, but that makes it that forum paradox where search returns TOO much information to be useful.

Like many others I've been reading about, I think that MFP is estimating my calories from exercise WAY high. That's making me very leery of eating back my exercise calories.

My question is, "How is MFP calculating those numbers?" What factors are being taken into account? Is it granting me more calories for that bike ride because it knows that I'm 280#? Is it taking into account my age and the general physical condition I picked when I signed up for MFP? Or does everybody who does "bicycle riding, light (10-12 mph)" get the same 400 Cal/hr?

If I had a better idea what was behind those Calorie numbers, I might feel more confident eating them. Right now, I'm essentially ignoring them, or eating back maybe a third of them at the very most. That's causing MFP to sometimes log 1500-2000 Calorie deficit days. I don't want to go into starvation mode.

minadeathclutch

RIGHT! that's why i don't eat any of mine back.. if i'm really hungry ill eat some, but most of the time no thank youuuuuuuuu

aamon17

Get a Heart rate monitor & ignore the MFP estimates.

olso2255

I have had the same experience. I finally got a heart rate monitor and it seems like MFP has in fact been generous in calorie burn. It was saying I was burning around 400 calories for a 30 minute run, and my HRM told me I was only burning around 230. YIKES! What a difference. I know at least for running/jogging the average for runners is about 100 calories per mile. So if you run, thats something to go by.

wrightqh

I think it is most often entered by a member, so it is all based on what that particular member's stats are? That would be my guess as when I work out, I wear a heart rate monitor. This gives me a more accurate read of my excersize and calories burned than MFP. If you are capable, a heart rate monitor would be a great investment to help with your calorie totals. Keep on working and best of luck!!!


Adam

melizerd

It does change based on your weight, I know when I started I burned more calories doing those activities than I do now (according to MFP).

I've been here a year and eat back about half my exercise calories since I still don't have a HRM. It's a good compromise and so far no plateau

HarlCarl

I thought it was strange to eat back the calories at first, but after losing 30 pounds or so I noticed that I got 'credit' for fewer calories the lower my weight turn out. I usually cut the time I've spent a little and never eat back ALL of the calories.

I'm nearing the six month mark and I am sticking with what works for me. MFP works for me.

swillis21

It can be way off I think But for running, it's accurate I've noticed. Other things not so sure, but you can even google the excercises you do the most off this site and then adjust it to what you've found for your weight. Also, when you set your lifestyle active or sedentary then you should not be logging those regular activities. So ie if you walk around a lot for your work and have set your lifestlye to lightly active or active, then you should not log those walks. Hope that helps

Azdak

MFP takes into account your weight when estimating exercise calories. That and the intensity of the activity is all you need.

It's important to remember that MFP is primarily a central gathering place for existing fitness information. In other words, MFP collects data that is publicly available and pulls it all together in one location with a simple interface that combines the general data with your personal data. And it does a very good job of doing that, IMO.

However, MFP data for exercise activity is ONLY as good as the quality of the data that is out there. Some of it is good, some of it isn't.

Simple exercise activities like walking and running have well-established, well-validated formulas for estimating exercise calories. If you are entering those activities, MFP estimates will be as good as anything out there, equal to or more accurate than HRM data.

The overall accuracy goes down from there, for a variety of reasons. Group activities such as classes are difficult to quantify for a general population because there is so much individual variety.

Casual, occupational, and recreational activities are the least accurate of all--basically the numbers are useless (and in most cases, these numbers should not be included separately in your activity plan anyhow). Again, this is not a fault of MFP--the research and data that this information is derived from is very spotty.

aamon17

Great answers! The reason I support use of the HRM is that MFP cannot assess when your heart rate (and subsequent calorie burn) is elevated above the average numbers that MFP uses.

For example, Monday I walked 5.0 miles for 84 minutes @ 3.5 mph/brisk pace.
-- MFP DATABASE = 760 calories
-- POLAR FT7M HRM = 1,192 CALORIES!!!

That's a 432 swing in MY favor! Why the difference? Because MFP doesn't know that it's 90 degrees outside and my core body temp is raise, elevating my heart rate. it doesn't know that there are some hills on my walking path. It doesn't know that my pace picks up when I get a "2nd wind". It doesn't know that I spent the 76/84 minutes in my "Fitness Zone" burning more cals faster, etc, etc, etc.

So, the numbers in MFP are useless for me, other than a baseline for pushing myself to exceed them.

My HRM was a very worthwhile investment. I hope this helps.

Azdak

Great answers! The reason I support use of the HRM is that MFP cannot assess when your heart rate (and subsequent calorie burn) is elevated above the average numbers that MFP uses.

For example, Monday I walked 5.0 miles for 84 minutes @ 3.5 mph/brisk pace.
-- MFP DATABASE = 760 calories
-- POLAR FT7M HRM = 1,192 CALORIES!!!

That's a 432 swing in MY favor! Why the difference? Because MFP doesn't know that it's 90 degrees outside and my core body temp is raise, elevating my heart rate. it doesn't know that there are some hills on my walking path. It doesn't know that my pace picks up when I get a "2nd wind". It doesn't know that I spent the 76/84 minutes in my "Fitness Zone" burning more cals faster, etc, etc, etc.

So, the numbers in MFP are useless for me, other than a baseline for pushing myself to exceed them.

My HRM was a very worthwhile investment. I hope this helps.

Here is what people need to know when interpreting the "data" they get from HRMs:

Yes, neither MFP nor any other calculator can account for intermittent hills in an outdoor walk. They cannot account for significant wind resistance.

However, when heart rate is elevated due to the heat, there is NO increase in calories burned. At that point, your HRM is overestimating the exercise calories, sometimes to a significant degree.

If your pace picks up due to a "2nd wind", you calories expended increases as well. If your pace picks up, you will cover more distance. A calculator will show the increased calories burned because your average walking pace increased.

Whether or not you are in your "fitness zone" is completely irrelevant when it comes to burning exercise calories. Caloric expenditure is based on absolute workload x body weight. In other words, whether walking 3.5 mph represents 70% of your maximum fitness level or 30%, you will burn the same number of calories (as long as weight is the same).

HRMs can be great tools, but it is important to understand their limitations. In the case you cited, a big chunk of that 432 calorie "swing" represents an erroneous overestimation of your exercise calories by the HRM.