Does MFP really overestimate exercise calories burned?

Ponkeen

Just wondering, as I have seen this mentioned in the threads. Has anyone reading actually put this to the test against another tracker? I would rather hear from those who have in fact put it to the test, or see a link to a reliable study, than hear people repeating what they have also read from other people in the forums here. Verifiable is preferred- how does one know for sure how reliable, or not, the exercise calorie tracking is?

hill8570

Depends on the exercise, the person, etc. You log your intake, you log your exercise, you monitor your weight loss (or lack thereof), and adjust over time. Any other approach is just trying to squeeze excessive accuracy out of inherently inaccurate measurements.

PrizePopple

Unless you are using a heart rate monitor (and likely the chest strap variety) then you will not know exactly what you burned, and MFP is only making a guess based on averages and your information. Those who DO have such HRMs at their disposal have noticed a discrepancy. So to err on the side of caution it's generally recommended to only eat back 50%-75% of what it says for calories earned through exercise. If you do that and lose at a faster pace than planned, and are logging accurately (weighing solids, measuring liquids), then you know it's likely closer to accurate for your activity type and duration.

LKArgh

No. But it is very easy to log exercise inaccurately.
For example, there are some exercises which have descriptions such as "fast" or "vigorous effort" etc. It is very easy for someone to judge as "vigorous effort" what someone else would call "relaxed".
Also you need to be careful about times. You might e.g. spend 60 minutes doing calisthenics, but how much was actually exercising vs resting, talking to a friend etc?

oilphins

It's really hard to say but I'd say it's pretty close. When I do a 10k run on my treadmill it says I've burned about 1000 calories at about 7.6 mph. When I do my 10k run outside my nike app says it's closer to about 830. Mfp says about the same as my app. So I'm assuming they both aren't way off. I knew 1000 was a bit much on the treadmill so I just go with what my app and mfp says.

Ponkeen

Thanks oilphins! That is what I was looking for- an actual test of some sort. The other feedback is helpful, too. I intentionally underestimate the amount of time I spend exercising in order to control for little breather moments, waiting at intersections, etc... I just wasn't sure beyond that if I could trust the count.

nordlead2005

The only way to know if it is close is to closely monitor food intake, exercise, and weight loss over a long period of time (or possibly spend lots of money on a lab to calculate it for you).

Much like BMR or TDEE estimators, they are good for the general public, but a specific individual could be +/-10%.

For me personally, I think it is very accurate for the activities I log (mostly walking and strength training) with the exception of Ultimate Frisbee. I don't run constantly when playing ultimate, in fact, I stand around a lot. So the ultimate entry should be a good bit lower than a running entry for the same time period but instead it is only slightly under. So, I manually adjust that down to factor in me being tired and not running to cover anyone.

Michael190lbs

The issue with counting calories from lifting weights especially if your lifting heavy (2-6 reps) is 2 minutes between sets your just sitting on your butt recovering for the next set. Take that that 2 minutes times 20 sets and you have 40 minutes of rest and 20 min of actually doing something if your lucky. Throw that into mfp and you get 800 calories burned which is more than likely 600 to many.. If your trying to lose weight and exercising to lose weight on a calories deficit why the hell would anyone want to eat the calories back is just beyond me.. Maintenance or muscle building yes eat some back to get at your unique calorie intake.

nordlead2005

Michael190lbs wrote: »

The issue with counting calories from lifting weights especially if your lifting heavy (2-6 reps) is 2 minutes between sets your just sitting on your butt recovering for the next set. Take that that 2 minutes times 20 sets and you have 40 minutes of rest and 20 min of actually doing something if your lucky. Throw that into mfp and you get 800 calories burned which is more than likely 600 to many.. If your trying to lose weight and exercising to lose weight on a calories deficit why the hell would anyone want to eat the calories back is just beyond me.. Maintenance or muscle building yes eat some back to get at your unique calorie intake.

60 minutes of strength training gives me ~250 calories, not 800 calories.

jemhh

I get 202 calories by logging 60 minutes of strength training. When I've used the MFP calorie goal, I've always eaten all of my calories back. I want to fuel my exercise. I also want to fuel my recovery. Recovery is a big part of building strength and building muscle and that takes energy. It's not all about how many calories are burned while actually lifting weights, IMO.

MobyCarp

PrizePopple wrote: »

Unless you are using a heart rate monitor (and likely the chest strap variety) then you will not know exactly what you burned, and MFP is only making a guess based on averages and your information. Those who DO have such HRMs at their disposal have noticed a discrepancy. So to err on the side of caution it's generally recommended to only eat back 50%-75% of what it says for calories earned through exercise. If you do that and lose at a faster pace than planned, and are logging accurately (weighing solids, measuring liquids), then you know it's likely closer to accurate for your activity type and duration.

I see the estimation factor with the calorie burn numbers generated by Garmin. When I don't wear the heart rate monitor, or the battery dies, Garmin produces higher calories burned than for similar runs when I do wear the monitor. I think I'm in pretty good cardio shape; someone else could see a difference in the opposite direction.

All calorie burn numbers are estimates, and the economic incentive for equipment makers is to overestimate the burn. That's why the common advice is not to eat back all the calories; they aren't all real.

That having been said, the base metabolic rate is also an estimate. It can be too high or too low for any given individual. Sometimes I think that most success stories are produced by people who (like myself) burn more calories than the canned estimates say they do, and that many of the "I can't lose weight" stories come from people who burn fewer calories than the canned estimates say they do.

jemhh

MobyCarp wrote: »

PrizePopple wrote: »

Unless you are using a heart rate monitor (and likely the chest strap variety) then you will not know exactly what you burned, and MFP is only making a guess based on averages and your information. Those who DO have such HRMs at their disposal have noticed a discrepancy. So to err on the side of caution it's generally recommended to only eat back 50%-75% of what it says for calories earned through exercise. If you do that and lose at a faster pace than planned, and are logging accurately (weighing solids, measuring liquids), then you know it's likely closer to accurate for your activity type and duration.

I see the estimation factor with the calorie burn numbers generated by Garmin. When I don't wear the heart rate monitor, or the battery dies, Garmin produces higher calories burned than for similar runs when I do wear the monitor. I think I'm in pretty good cardio shape; someone else could see a difference in the opposite direction.

All calorie burn numbers are estimates, and the economic incentive for equipment makers is to overestimate the burn. That's why the common advice is not to eat back all the calories; they aren't all real.

That having been said, the base metabolic rate is also an estimate. It can be too high or too low for any given individual. Sometimes I think that most success stories are produced by people who (like myself) burn more calories than the canned estimates say they do, and that many of the "I can't lose weight" stories come from people who burn fewer calories than the canned estimates say they do.

I think these are really good points and observations. People would be well served by starting with the stock numbers and then adjust based on what actually happens when they follow them. And by follow them I mean actually eat to that level, not eat under it "just to be safe."

Michael190lbs

Maybe the calorie counter device people secretly want people fat so they can sell us all products???

WingardiumLeviosa91

Yes, after 65 mins of elliptic training the machine max showed 500 cals burned, and that's if I push myself way too hard. MFP on the other hand shows around 700-800 calories for the same level of exercise. I enter what the machine says, not the app.

ScubaSteve1962

Here's screen shot, the first elliptical is from my activity monitor, the second is what MFP says I burned. My activity monitor is also less than what the machine says I've burned.

tincanonastring

I did a 5-mile run yesterday at a pretty steady HR. My HRM (chest strap) showed a burn of 650, and that included my warm-up and cool-down walks. MFP has me burning a total of 850 calories for the same time periods of walking and running. I know even my 650 from the HRM is probably high because I didn't wait for my HR to settle between activities.

Mouse_Potato

I'm sure it depends greatly upon the type of exercise you are doing. I have found that my HRM and my Fitbit actually give me higher calorie burns than MFP in many cases, particularly when walking or running.

Ponkeen

Thanks, guys! Some very helpful answers here.

nordlead2005

WingardiumLeviosa91 wrote: »

Yes, after 65 mins of elliptic training the machine max showed 500 cals burned, and that's if I push myself way too hard. MFP on the other hand shows around 700-800 calories for the same level of exercise. I enter what the machine says, not the app.

But you don't know which is more accurate unless you monitor food, exercise and weight loss. You just artificially picked the lower one because you wanted to.

Same with ScoobaSteve, does he really know that his activity tracker is more accurate, or is he blindly following it? Activity trackers are still doing estimations after all (granted, if I had to choose blindly I'd choose the activity tracker over MFP).

Again, it will vary per person and how they choose to log the activity in MFP (which can make a big difference too).

Jruzer

I find it's pretty accurate for me for the exercises I do. But I've been pretty careful to align multiple sources of information: other trackers, HRM, and actual observed weight loss/gain over the long term.

lemurcat12

I think it's accurate for some things, not for others, and it varies person by person.

The fact is that it's a lot easier to estimate some activities than others. If it knows how far you ran and in what time and how much you weigh, it should be pretty accurate. The only problem is that it doesn't deduct out how many calories you would have burnt anyway (neither do most apps or HRMs), which doesn't make much difference for a shorter run, but will throw off the calories quite a bit for a long run.

Walking is more affected by this, as is biking. Also, with biking, there are all kinds of things that vary the burn, like wind, the type of bike you ride, the terrain you are on, etc., which obviously cannot be taken into account in the estimate.

With something like the elliptical or circuit training or weight lifting or swimming it's going to depend on (A) what you do and (B) actual intensity. Many people perceive themselves as exercising intensely (because it is for them, they are out of shape) when it's not that intense in terms of what's meant, and so end up with an overstated exercise burn. I think that's why the elliptical (which presumes intense) often seems to be one of the worst offenders.

My "evidence" -- based on this analysis I used most of the burn from certain activities (like runs of 6 miles or less) and cut the calories from others varying amounts and generally had it work out consistently with what I expected to lose.

But of course there are other variable factors, so who knows.

Rather than worry about all this it makes sense to me to pick an approach and if you lose more or less than planned over a few weeks, adjust.