How accurate are MFP exercise calories?

Cindyinpg

I wonder why folks think a HRM calorie reading is accurate. How do you know?

The main reason I believe my Bodymedia Fit is more accurate than MFP numbers is through simple experience. If I have a weekly average deficit of 7000, I will generally lose 2lbs. That can vary with salt intake, Time of the Month and so on, but in general, it seems accurate and they advertise it to be within 5% accuracy. Most of these activity trackers are meant to be more motivational tools than dead on accurate anyway. We have to work with the technology we have and I believe that we can only trust the numbers when we see results over the long term. MFP numbers are going to work for some people. But they're way off for me on the cardio. Someone mentioned Wii Fit, as well and when I'm playing, their numbers are dead on with my BMF. Very reassuring.

MelissaHollingsworth

I have also wondered this. I'm always worried about the calories burned being too high so I reduce it by half or 40% most of the time. For instance, today I did an hour of Zumba and it had it at 616 calories burned so I reduced it by 200 calories. I'm also usually below my calorie goal for the day. MFP says I'll be at a certain weight in 5 weeks and so far in 3 weeks I haven't lost a pound. I'm under my calorie goal, drinking approx. 100 oz of water a day, and exercising 5 days a week. I should see the scale move a little, but I'm not. Maybe I just need to get a FitBit. Who knows!

ashleyoh33

MFP has a tendency to double numbers for me. If you are running and doing ultimate frisbee and plan on eating back the calories, I would tell MFP you worked out for half as long as you did. 80 mins = log for 40. Or find an online calculator that asks sex, age, weight, and height and manually enter it. In a perfect world you should use a good HRM, but I know not everyone has $100 to drop on one of those.

Shelby1582

When I got my heart rate monitor I realized that MFP overestimated them a lot.

mazdauk

I wonder why folks think a HRM calorie reading is accurate. How do you know?

This.

Whatever technology we use is unlikely to be accurate. If the MFP estimates plus your recommended calories = weightloss - use them. If they don't, play around with other technology, or other methods (higher intake and no exercise calories eaten, for example) until you find something that works for you. Everyone's metabolism is different.

What I would say is to check your calories though - are you weighing your portions or "guessing" what 75g dry pasta looks like? Doesn't matter how accurate the "calories burned" are if the "calories in" are wrong to start with.

iecreamheadaches

For me too, many of the exercises are overestimated by nearly double. As an example, MFP had me burning about 450-500 calories for 30 minutes on the treadmill, when I actually only burn 300, according to my Bodymedia Fit. And that 300 calories includes the calorie or 2 a minute I burn just sitting around, ( my BMR) , so I'm really burning 250ish. If you really want accurate numbers you might want to look at getting a Bodymedia Fit, a Fitbit, a HRM etc. I always cringe when I see people "burning 500 calories doing 20 minutes of housework... Or "800 calories moving boxes" and then they're eating back the calories and could be inadvertently sabotaging themselves.

this. I sometimes use MFPs general estimate, but I never ever eat all of my calories back. I try to hit 1200-1300 a day when I have "big burns" from mfp, just to make sure I dont over eat and sabotage myself.

annakow

It's not, the bigger you are, more calories you burn while exercising, so it's calculating each of us individually.
'On average, aerobics burns more than 400 calories per hour. A person who has a weight of 130 lbs burns 354 calories per hour when doing aerobics, while a person who has a weight of 190 lbs burns 518 calories per hour.'

check calculator

http://www.healthstatus.com/calculate/cbc

Shelllbeee

I've checked 2 different calorie burning calculators online, my treadmill, and the app RunKeeper....
MFP was lower than all of those.... so I use MFP. *shrugs*

Like most things in the world, it works for some and doesn't for others I guess.

shadus

Here's the short short version.

If you weight between 140-170 lbs, you're performing steady state cardio activities, and monitoring heart rate...

The calculations are pretty good.

If you weigh outside that range, are not performing steady state cardio, and aren't monitoring your cardio...

The calculations are abysmal.

All of that said, I figure my exercise calories at 50-70% of the suggested values... and my weight loss, at least with what i do personally exercise wise, is inline with what I would expect 95% of the time or better.

TL;DR - If you're not using a heart rate monitor or not doing a steady state cardio activity, or are not "overweight" or "normal" bmi... take 50% of the listed amount as a good starting point.

EDIT: This isn't a MFP thing at all btw, this is a "the formulas fail outside certain criteria" thing. All of them are massively off.

paulperryman

might be seeing different but for me they are only as accurate as the numbers everyone else puts in, once you use a exercise in the list and set a burn that you have calculated via other means it uses that calculation for the next time you do the same exercise

It seems to me say i put walking for 40mins and 447 calories the next time i chose walking it will have worked out that the last time i did that i burned about 11.5 calories a minute and lets say i only did 30mins this time it will automaticaly calculate it at 345, then again it could have some calculation for weight/height to work out a moderate effort, machines at the gym work out a basic burn based purely on weight nor height and age and those numbers tend to be alot lower for me then my HR monitor would register, MFP was the same to start with.

I have always had access to a Heart Rate Monitor so never went with what MFP said or the gym machines.

paulperryman

Here's the short short version.

If you weight between 140-170 lbs, you're performing steady state cardio activities, and monitoring heart rate...

The calculations are pretty good.

If you weigh outside that range, are not performing steady state cardio, and aren't monitoring your cardio...

The calculations are abysmal.

All of that said, I figure my exercise calories at 50-70% of the suggested values... and my weight loss, at least with what i do personally exercise wise, is inline with what I would expect 95% of the time or better.

TL;DR - If you're not using a heart rate monitor or not doing a steady state cardio activity, or are not "overweight" or "normal" bmi... take 50% of the listed amount as a good starting point.

EDIT: This isn't a MFP thing at all btw, this is a "the formulas fail outside certain criteria" thing. All of them are massively off.

THis is sound advice

fatfudgery

I wonder why folks think a HRM calorie reading is accurate. How do you know?

Because there's quite a large body of science establishing the relationship between MHR, VO2 max and calories burned during exercise and regressing predictive formulae from large samples of actual experimental observations. There's also a lot empirical confirmation of the math by a lot of HRM users out there, from casual dieters all the way up to professional athletes.

Joehenny

Way off. I just do an extra few mins of exercise to accommodate.

SuffolkSally

Mfp estimates are very close to the estimate my HRM gives me, by the time I've deducted my BMR from the HRM reading. But they're all just estimates, the best thing is to go by results...

annie7hudds

this is a a timely thread.

I was also wondering how accurate the calculations are/can be.

As an example - this morning I went for a run. My Garmin says I burnt 579 calories. - Now that knows how fast I ran, up how many hills( It is very hilly around here) and my weight. I don't have a HRM on it however.

MFP calculated that for the speed and length of time - I expended 417 calories.

So in this instance, the exercise calories are UNDER represented.

HRM I suppose will be the most accurate?

enjoythesound

I have a related question so maybe someone can help me too!
I have exercise-induced asthma so my heart rate is usually very high when I workout. This morning I went for a 35 min run at something around 9min/km (pretty slow I know...), trying to keep my heartrate as steady as possible, it is usually between 165-168 with peaks at 172.
My HRM is going for 400kcal burned but MFP says 340kcal and Runkeeper which I use for mapping my run is only at 245kcal !!!

I don't know which one is the most accurate so what do you think?

CarlKRobbo

If I believed MFP's calories burnt...

Climbing would mean I need to eat another 3000 calories!

Kickboxing would mean I need to eat back another 1500 Calories!

My overall calories burnt would mean I'd have to eat around 9000 calories extra a week!

I therefore work out my calories via TDEE, and don't log my exercise.

I'm bulking at the moment, and eat 600 calories more on those days, and I gain weight at the right rate....

mattyval

I think what people are missing is this: When you wear a HR monitor or use a cardio machine those things stop counting the second you take the monitor off or get off your machine.

The reality is that your body spends at least another 25% of its calories recovering in the following 20min or so (dependant on the stress of the session). I thinks its fair to count those calories as they are directly related to the fitness session you have just done. So if MFP is overestimating calories by 25% compared to a HR monitor or running app then i think it is BANG ON accurate.

smalls9686

Ditto, it is way off for most things for me anywhere to 150-300 calroies off (under!) and if I am doing yeard work...forget it! MFP is normally off 500-700 calories (too low!)

Buy a HR monitor and track it that way -- I wouldn't trust what MFP says, just like you shouldn't trust what an elliptical or treadmill says.

smalls9686

Weird b/c MFP is always about 20-25% under what my HRM has.

I think what people are missing is this: When you wear a HR monitor or use a cardio machine those things stop counting the second you take the monitor off or get off your machine.

The reality is that your body spends at least another 25% of its calories recovering in the following 20min or so (dependant on the stress of the session). I thinks its fair to count those calories as they are directly related to the fitness session you have just done. So if MFP is overestimating calories by 25% compared to a HR monitor or running app then i think it is BANG ON accurate.