How true are MFP's Exercise Calories Burned?

heybales

I have read that heart rate monitors really aren't that accurate at estimating calories burned. Even this article that states Polar heart rate monitors are pretty good say they are only about 75% accurate (http://www.livestrong.com/article/490909-the-accuracy-of-calories-burned-in-polar-heart-rate-monitors/). I have no idea if their numbers are right, but I have seen many places saying heart rate is not a good predictor of calories burned. Even devices such as the Bodymedia Fit and BoduBugg don't even use heart rate at all because they say it doesn't add value to their methods. I wear a heart rate monitor and like it, but I'm not sure the calories are accurate. My Garmin 305 was usually within 10% or so of my Bodymedia Fit, but I think it uses distance ran, weight, and gate to estimate calories.

Also, heart rate monitors typically only do a decent job with activities like walking and running, not strength training: http://www.sparkpeople.com/community/ask_the_experts.asp?q=75

Depends on which Polar, and are you accepting default values, or figuring out your own stats, and sadly, are you male or female.

3 guesses as to which gender get's defaults that are most inaccurate. First 2 don't count.

http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study

Correct on aspect that anything non-aerobic, actually, steady state aerobic, will be inaccurate. So wearing it all day, or for intervals, or weight lifting, those are either anaerobic, or not steady state, or not aerobic between 90-160 bpm.

Edit: very true on the Garmin 305 - didn't even use HR is calorie estimates. But the newer Garmins use a algorithm from Firstbeat that studies have shown to be very good, and actually for anaerobic too. Because it incorporates your VO2 and breathing rate.
It's very interesting that later in a ride, even with the HR the same, the calorie count will go down because I'm breathing easier. It can tell the HR is elevated from heat, not effort to produce energy. Very cool.

JustinJoanknecht

Interesting......my Polar FT7 is giving much LOWER calories burned than MFP says...........I am big (6'4") and heavy (104KG) but not massively overweight, only a little and I play a lot of squash which is high heart rate stuff..........but on my walks/runs, I'm getting a much lower (typically 50%) reading of calories burned off the HR monitor than MFP's estimate.............thoughts anyone?

heybales

Interesting......my Polar FT7 is giving much LOWER calories burned than MFP says...........I am big (6'4") and heavy (104KG) but not massively overweight, only a little and I play a lot of squash which is high heart rate stuff..........but on my walks/runs, I'm getting a much lower (typically 50%) reading of calories burned off the HR monitor than MFP's estimate.............thoughts anyone?

The exercise database that MFP uses only takes into account your weight, not gender, not age, and of course no idea of your level of effort.

I just did an hour recovery walk last night, and actually MFP was only 20 cal higher that HRM.
So their entry for walking 4mph (which they don't know hills too, right, 4mph up hills is harder than flat) must be based on about a HR of 40% of max - which is not much effort at all.

So if walking 4mph is harder effort for you and your HR reaches 50-60%, than MFP will underestimate.
If it is even less effort because you did keep it flat perhaps, than MFP will overestimate.

If you are heavy but got the muscle to make it not that difficult, likely MFP will overestimate.

Here is calculator that is interesting if using treadmill - because the energy to move certain mass a speed and distance at an incline is mathematical, and interesting comparison as to how efficient your system is.

http://www.exrx.net/Calculators/WalkRunMETs.html

cobaltis

I assume they over estimate a lot but some things are pretty accurate. The biggest problem if a 6'4'' 325lbs man runs 6mph for 30 minutes he is going to burn a lot more calories than a 5' 4'' 130lbs girl.

It actually takes your weight into account here.... but still I think it overestimates a lot of things, I try not to eat back anywhere near all of my exercise calories

ichigo007

i think MFP also needs a spot where you can put your known bofy fat % so it can more accuratlly calculate your calories and true bmi

heybales

i think MFP also needs a spot where you can put your known bofy fat % so it can more accuratlly calculate your calories and true bmi

Oh yeah, better BMR estimate to base their calcs on would be great, even give the bodyfat% calc.

They could also have option to use ticker for that stat, or perhaps measurements since many times those will go down faster than weight will.

Rhea30

My HRM has been pretty closes to MFP. I don't work out with the same intensity each time so it fluctuates. Sometimes lower then MFP, sometimes higher and sometimes nearly spot on.

MumMumOfMany

No idea how accurate it is but will say one thing, durin my weight loss process ive only eva used MFP's calorie estimates for both foods eaten and what burned through exercise and im dwn 57lb. so they must be doing something right yh? :-)

ErinBeth7

They are low for me so I calculate my own calories burned by heart rate

They're low for me too. I'm 5'9", 174lbs and my calories burned, according to my heart rate monitor, is always higher. If you're interested in an HRM check out the Polar brand. They have a whole range of monitors to fit your needs. There are also basic HRMs at Walmart and Target.

AlsDonkBoxSquat

In my experience they are seriously inflated.

FitToBeFab

I use MapMyRun or MapMyFitness calculators. I've always used them (the several times I've started and stopped MFP) and been successful every time.

I don't know why I feel they are more accurate - maybe because they specifically ask for height and weight, distance, and time (for runs and walks). They are always less than MFP, usually by 20 cals or more.

FrugalMomsRock75

I typically get an overestimation from mfp. If I ride my stationary bike in vigorous mode, the moderate effort on mfp is very close to what my HRM tells me.

The elliptical... if I enter mfp's value, it's over by about 10%-ish.

walking... I select the carrying load of 15 pounds and it tells me 295 for my walk this AM, but my HRM said I burned just over 500. If I just select the "very brisk pace" (4.0 mph), it says 421-getting closer, but still not there. I think the stroller added that extra burn for me.

It just depends. It really does pay to get a HRM.

amandainez08

It works for me and what I do. It may overestimate, but only by a few calories. I do Shaun T's Hip Hop Abs, and log it as "Aerobics, high impact." I've lost weight, so it must be close to accurate. However, when I did my elliptical, MFP says I burned I lot more calories than my elliptical machine did. I would suggest buying a HRM and calculate your calories burned that way. That would be the closest thing to accurate as you could get when it comes to calories burned. Everyone is different. My heart rate may start speeding up before the next person, or vice versa; therefore, I'd burn more calories than that person. Your heart rate plays a big role in burning calories. Also, if your body gets "used" to you doing the same thing every day. For example, your body may not burn as many calories this week as it did two months ago when you first started doing the exercise...and only that exercise. In these cases, MFP definitely isn't very trustworthy.

sjschewlakow

I have used MFp for all my exercises. I eat back most of my calories. I have been on MFP for 145days a of today and have lost 25lbs during that time. I am still losing. Works for me!

heybales

In my experience they are seriously inflated.

You have gotten seriously efficient compared to the folks in the studies then. :noway:

How does it feel to be so aerobically fit that it's hard to get a good calorie burn on unless you kill yourself? :grumble:

jfrankovich

Part of why MFP estimates are often too high is that your daily goal is based on a built-in 24 hours of regular activity. So if you log an hour of running on top of that, it's like saying you had a 25-hour day. To be accurate, when logging an hour of exercise, you would have to subtract an hour of normal activity. Since you can't really do that, I just decrease the amount of minutes of exercise I log (versus what I actually did) to make up for it.

For example, if my daily expenditure is 2400 then my typical hourly expenditure is about 100. If I exercise for an hour and MFP says it burned 400 calories, that's really only 300 calories more than I would have burned anyway. So I would only log 45 minutes of that exercise (instead of 60) since 300/400 = 3/4.

I've had great success doing it this way, losing weight at very nearly the same rate as expected from my MFP goal settings.

Overestimating exercise calories in the first place could well be part of why many MFPers are hesitant to eat them all back.

Another issue is that some activities, like cleaning, bowling, or golfing, for example, can involve a lot of pausing in between actual activity (waiting while others play, etc). You shouldn't get credit for a full 2.5 hours of golfing if a lot of that time was spent just standing or sitting around. Instead, I try to estimate how long it would have taken had there been no interruptions.

jfrankovich

http://www.fitsugar.com/Whats-Diff-Total-Calorie-Burn-Net-Calorie-Burn-1523858

heybales

http://www.fitsugar.com/Whats-Diff-Total-Calorie-Burn-Net-Calorie-Burn-1523858

That's yet another good reason for just doing a TDEE Deficit based method. With exercise already included in the TDEE method, it doesn't really matter.

But you did give me a good idea for improvement to a spreadsheet, where you could use your own HRM calorie burn estimates to get better TDEE estimate.

But of course if doing that to get better estimate, better remove what was planned on happening anyway.

Thanks for the reminder.

Also goes to show, unless doing a recovery type workout, if you are going to give 30-60 minutes for a workout, you might as well push it and get some serious calories, so that effect is less.
Someone barely walking 2 mph just isn't getting much above expected normal anyway.

barfleurjo

I agree, having spent four sessions in the gym this week, the MFP rates are too high. Today I manually changed the figures to be what my bike & cross-trainer said I'd burned as that was at least working on effort level, weight, age etc so I think it's more accurate.

LorinaLynn

It depends on how precise the activity is.

For running or walking, where you're going a set or average pace for a set amount of time... it's probably pretty close.

For something more vague, like the elliptical, where there's no variation for resistance or pace, it has as much chance of being right as a broken clock.

neverstray

It's about right. Who cares anyway, it's a benchmark, not an actual measurment. If you're not losing, eat less or workout more. Doesn't matter at all. I wish people wouldn't get so hung up on it. NOTHING is accurate. It's all a big giant guessing game. Calories on food are off by at least 20%. Your scale is off by a few lbs give or take 5 lbs. Who cares? All that matters is consistency. Always use the same method, scale, and measurment technique and it will all be relative.

Also, and this bugs the holy crap out of me, if a 100 calorie food is 100 calories, do you think that means the same thing to everyone? Does an 80-year-old inactive woman process that 100 calories the same as a 20-year-old male athelete, or a 3 year-old kid. Of course not. It's all just a big estaimate. nothing is that accurate. HRM's are not all that either. Biggest scam in the world. People here cling to them like they are the holy grail, and then use them wrong by walking around at work with them on. LOL. Not what they are designed to do, and they are wrong when you do that. Plus, all they know is that your heart is beating, thus the name Heart Rate Monitor, they have no idea how many calories you burn. LOL.

Yosemite4vr

I only trust my HRM.

ethansmug

I like em, cause I can flick my toes for 5 minutes and it will say I burned 12,000 calories =]

MuscleJunkieK8

I use my own way to check for calories burned, fat burned, heart rate. Either the machine I am working on in my home gym is set according to my height, weight, gender, or a HRM.

I rarely ever trust MFP, unless I'm in a hurry and did a quick jog, something like that.

amd895793

they aren't incredibly innacurate because it factors in your weight with the burn... when i lost about 5 pounds i saw a difference in the same excersises.. small difference of course!

MissyBenj

It sounds like I need to invest in a HRM!

MissyBenj

I like em, cause I can flick my toes for 5 minutes and it will say I burned 12,000 calories =]

This made me laugh out load. I always feel really good when it says "600" calories burned.. kind of bummed that it's a high guess.

wavdawg4

No idea how accurate it is but will say one thing, durin my weight loss process ive only eva used MFP's calorie estimates for both foods eaten and what burned through exercise and im dwn 57lb. so they must be doing something right yh? :-)

That is awesome :-)
I was using the elliptical's machine "calories burned" for quite some time, but it doesn't take my weight into factor. It just counts the time, the level of difficulty, and calories burned. So for 5 minutes -hard by the way I was only burning a tiny amount but according to MFP's numbers the burn was higher.. I've decided to start using MFP's numbers. On the days where I do use the elliptical I tend to get a little bit hungrier and always eat something else. If I used the ellipticals' numbers I'd be over calorie for that day, MFP's I'd be just fine.

Tori_356

well I just got an HRM. For 35 min on the elliptical MFP said 384 calories. The machine said 297 and my HRM said 257. Guessing is fine and all but if you really want an accurate count a HRM is the way to go! I finally got one after over a year... love it

TrailRunner61

If you don't have a HRM, using MFP's exercise database is better than nothing. It worked just fine for me and I lost 40lbs in about 5 months using it. I did buy a HRM and I like using it and getting more accurate data because on different days, even weather affects my cals burned. For instance if it's hot out, I will burn up to 200 more cals on one bike ride and the more it cools off the lower that number gets. Also, as I've lost weight, I burn fewer cals. per exercise session. The HRM keeps me from eating too many cals back.

If you do get one, I love the Polar FT4. It's worth every penny.