calories burned expirement: MFP vs Polar vs Body Bugg

CeleryStalker

"it uses temperature, galvanic skin response (sweat) and motion sensors to estimate how many calories you're burning "


That's interesting to know, and now that I look back over my activity manager, I see that it doesn't log HR at all. I wonder if I knew that at one point and just forgot it while the BB was hiding out lost in my house for 2 years, LMAO!

Grumble. Maybe my next purchase is going to be a PowerTap. Why's it so damn hard to accurately estimate how many calories someone is burning? >=o(

CeleryStalker

ps...its good to know my polar is probably the most accurate....it's what i've been using the longest.

tolygal

I was advised by BodyMedia (same device as BodyBugg; different software) tech support that the device is not accurate for bike riding. In fact, they advised me to remove the device during bike rides, and just estimate the calories using an online calculator!! That's when I decided to send it back.

I think the # on your polar is probably the closest to reality.

They had damn well better not tell me this. For what this thing costs, in addition to the $7 a month subscription fee, I want something that's accurate. BB is supposed to be the MOST accurate calorie tracker out there for consumer use. >=o(

I think it is accurate - I always saw good results when I stayed on track. You have to remember how it works. If it can't measure something, it can't be that accurate. It's not going to be the best measurement for excercises where your arms are stationary.

Here's how it works (from http://www.bodybugg.com/science_behind_bodybugg.php). On the bike, you're missing #1 because it can't tell that you're legs are doing most of the work.

1.Accelerometer - The accelerometer in bodybugg® is a tri-axis micro-electro-mechanical sensor (MEMS) device that measures motion. This motion can be mapped to forces (g-force) exerted on the body. By taking gravity and motion into account along with the other sensor data, the wearer's body context and true level of physical exertion can be accurately predicted.

2.Heat Flux - The bodybugg® also contains a proprietary heat flux sensor located on the side that measures the amount of heat being dissipated by the body via a thermally resistant material. In short, this sensor measures how much heat the wearer's body is giving off. Heat flux is an important parameter because the body tends to heat up the faster it burns calories.

3.Galvanic Skin Response - Better known as GSR, this sensor is comprised of two "hypo-allergenic" stainless steel electrodes on the back of the armband that measure skin conductivity. Skin conductivity is how much an electrical current can pass between two points on the surface of the skin and is affected by sweat due to physical exertion as well as emotional stimuli such as psychological stress.

4.Skin Temperature - Skin temperature is measured by using a highly accurate thermistor-based sensor located on the back of the bodybugg®. Looking at continuous measurement of skin temperature in conjunction with data collected from the other sensors can reveal the body's core temperature trends which are affected by the level of a person's physical exertion or lack thereof.

The data these 4 sensors collect, in conjunction with the wearer's specific body parameters (age, gender, height, weight) enable the most accurate estimation of energy expenditure on the market today outside of a clinical setting.

Hope that helps some!

kate2004rock

BUMP --- interesting experiment!

As another poster said, I'd also be interested to know the variations between another form of excercise--even just a walk.

taso42_DELETED

I was advised by BodyMedia (same device as BodyBugg; different software) tech support that the device is not accurate for bike riding. In fact, they advised me to remove the device during bike rides, and just estimate the calories using an online calculator!! That's when I decided to send it back.

I think the # on your polar is probably the closest to reality.

They had damn well better not tell me this. For what this thing costs, in addition to the $7 a month subscription fee, I want something that's accurate. BB is supposed to be the MOST accurate calorie tracker out there for consumer use. >=o(

Call them or hit up the tech support on their web site. I was pretty floored when they told me this.

I think it pretty much is the best consumer calorie tracker out there, for "general life activities", but for certain things like weight training and bike riding, I think it has a margin of error, like anything else.

CeleryStalker

Sucks....I'll call them tomorrow. I've poked around on the web and have found multiple resources advising to wear it on the thigh, about 2" above the back of my knee. We shall see. The experiments shall continue!

Thanks guys!

HeatherFeather10

Just wondering if you are wearing the Polar FT using a chest strap by your heart or on your wrist ? I have heard you won't get really accurate results unless you use the chest strap. I've got some links that I'll post later once I find them.

StuAblett

I told you this was a worthwhile thread to start :bigsmile:

I just got a Polar CS200cad unit for my bicycle, I'm really looking forward to seeing some much more accurate results, and being able to put them up online on a diary of sorts. :happy:

Keep on testing and tell us the results please!

irenerose25

Very interesting. Will be cool to see how it works out!

CeleryStalker

Just wondering if you are wearing the Polar FT using a chest strap by your heart or on your wrist ? I have heard you won't get really accurate results unless you use the chest strap. I've got some links that I'll post later once I find them.

Chest strap. Do they make HRMs that go on the wrist? I'd never seen one!

shar140

With polar you have to add age, weight, height and all the other stuff to. I just got a polar FT4... so now I wonder. I guess this is why we don't eat all of our calories back. Keep us posted.

Yes, my age, weight, height, resting heart rate, sex, all that stuff is loaded into my Polar. Mine even does a fitness test to get an idea of your V02 Max.

I was going to ask if the VO2 max settings were the same, but I wasn't familiar with how the BB worked - completely different, apparently.

Also, keep in mind that as you become more fit, your VO2 max will change - your body will become more efficient. The VO2 max test that you mentioned - was that built-in to your Polar? Just curious, as mine is approaching 3 years old so it doesn't have all the new fancy programming! lol...Mine does have those user settings, but no fitness test. I've tried a couple VO2 max tests but can get vastly different results (though all the tests are just theoretical, I was hoping they would be somewhat similar!).

I was always curious how the BB compared to Polar (I have an F6), so thank you for posting this!

CeleryStalker

I was going to ask if the VO2 max settings were the same, but I wasn't familiar with how the BB worked - completely different, apparently.

Also, keep in mind that as you become more fit, your VO2 max will change - your body will become more efficient. The VO2 max test that you mentioned - was that built-in to your Polar? Just curious, as mine is approaching 3 years old so it doesn't have all the new fancy programming! lol...Mine does have those user settings, but no fitness test. I've tried a couple VO2 max tests but can get vastly different results (though all the tests are just theoretical, I was hoping they would be somewhat similar!).

I was always curious how the BB compared to Polar (I have an F6), so thank you for posting this!

Hi! Yes, the fit test was built into my Polar. It's an F6. When I'm actually working out and taking care of myself (admittedly that hasn't been going on for quite some time), I run it once a month or so. Sadly, a couple years ago, I was "elite". Now it just throws a frown up on the screen and calls me a fattie. LMAO

HeatherFeather10

Just wondering if you are wearing the Polar FT using a chest strap by your heart or on your wrist ? I have heard you won't get really accurate results unless you use the chest strap. I've got some links that I'll post later once I find them.

Chest strap. Do they make HRMs that go on the wrist? I'd never seen one!

Yes they do unfortunately - but really it only calculates a pulse signal and isn't very accurate when using it as a calorie counter.
I've seen them at department stores.

CeleryStalker

Wow! That's something else!

ilsie99

I really think you aren't going to get an accurate calorie burn unless you know how much power was exerted on the bike ride. I would definitely expect MFP to be off, since there is no way to tell how much you exerted yourself.

For another data PT, MFP is usually within 10% of my garmin 310xt when it calculates calories burned for running.

CeleryStalker

Ah, now see? I've got a garmin as well (a garmin 305 with cadence sensor). The garmin is RIDICULOUS compared to the Polar. I did the same experiment with Polar and Garmin when I first got the Polar and was shocked to see that the Garmin reported on average, more than 1,000 calories than the Polar reported. Both had my age/sex/weight/height/gender programmed into them and monitored my heart rate. As a matter of fact, I bought the Polar because I just couldn't believe that in a 90 minute ride, I was burning almost 3,000 calories.

From the research I've done, Polar is the industry standard in providing accurate calories burned and Garmin is known to report higher than true numbers.

I'm truly thinking of getting a Power Tap for my bike. The only thing holding me back is the cost factor. Is it really worth over $1,000 for me to know how many calories I'm burning? I wouldn't really get it for the training purpose of knowing how many mets i'm putting out or whatever, I just want to know my calories burned!

Sadly, lots of people lose weight without the use of HRMs and calories burned estimators. I wish I could go back to that simple time before the technology existed, but my techie nerd brain wants the raw numbers!!

Found this post on a message board in regards to comparing the results from PowerTap to a Garmin 705. I will paste the post, but I'm laughing at the first response, which was 'people actually use the calorie number off Garmin?' LOL Don't get me wrong. I love my Garmin...but not for the purpose of tracking calories. Oddly enough, I've also read that the Garmin is more accurate for running than for cycling, so I guess you runners have nothing to fret!

"Rode today with the Powertap and a 705, mostly playing around, and to check the calibration of the Powertap's mileage.

The inaccuracy of the Garmin's calorie measurement was laughably bad, to the point of being worthless.

On a relatively easy one hour flat ride, average speed 19.4 mph, the Powertap indicates I burned 780 calories (applying the formula below). The Garmin calculated it at 1625.

And how do we know the PT is right and the Garmin wrong?
The PT measures actually energy expended in Kilojoules. 4.18 KJ = 1 calorie. However, given a cyclists efficiency in converting dietary calires to energy at the hub, the relationship is closer to 1 to 1.

Lab tests show the efficiency is between .18 and.24, which means that calories expended is actually between 1.05 and 1.15 x KJ.

Using kJ x 1.1 =Calories means you'll be accurate within plus or minus 5%. (which is what I used for the PT calories) So even a 5% varience in the PT calculation would still leave the Garmin data off almost 100% high

http://www.saris.com/CalorieCalculator.aspx

So if you're calculating you calorie replacement needs off your Garmin, you might not be losing too much weight."

link to the thread, if anyone is interested: http://www.bikeforums.net/archive/index.php/t-461424.html

aviduser

Trust Polar and nothing else. Polar uses your heart rate (cardio exertion), weight and age, as well as a fitness level/max heart rate measurement, to determine your calorie expenditure.

That is the best measurement.

BTW, in my experience, light cycling for 1 hour burns about 500 calories. Hard cycling for the same time is between 800 and 950, depending on how overweight and how fit I was at the time.

Mrs_TrimWaistFatWallet

I wear the BodyMedia (similar to BodyBug) on my calf when I bike. It gives a more sensible number.

ilsie99

Ah, now see? I've got a garmin as well (a garmin 305 with cadence sensor). The garmin is RIDICULOUS compared to the Polar. I did the same experiment with Polar and Garmin when I first got the Polar and was shocked to see that the Garmin reported on average, more than 1,000 calories than the Polar reported. Both had my age/sex/weight/height/gender programmed into them and monitored my heart rate. As a matter of fact, I bought the Polar because I just couldn't believe that in a 90 minute ride, I was burning almost 3,000 calories.

From the research I've done, Polar is the industry standard in providing accurate calories burned and Garmin is known to report higher than true numbers.

I'm truly thinking of getting a Power Tap for my bike. The only thing holding me back is the cost factor. Is it really worth over $1,000 for me to know how many calories I'm burning? I wouldn't really get it for the training purpose of knowing how many mets i'm putting out or whatever, I just want to know my calories burned!

Sadly, lots of people lose weight without the use of HRMs and calories burned estimators. I wish I could go back to that simple time before the technology existed, but my techie nerd brain wants the raw numbers!!

Found this post on a message board in regards to comparing the results from PowerTap to a Garmin 705. I will paste the post, but I'm laughing at the first response, which was 'people actually use the calorie number off Garmin?' LOL Don't get me wrong. I love my Garmin...but not for the purpose of tracking calories. Oddly enough, I've also read that the Garmin is more accurate for running than for cycling, so I guess you runners have nothing to fret!

"Rode today with the Powertap and a 705, mostly playing around, and to check the calibration of the Powertap's mileage.

The inaccuracy of the Garmin's calorie measurement was laughably bad, to the point of being worthless.

On a relatively easy one hour flat ride, average speed 19.4 mph, the Powertap indicates I burned 780 calories (applying the formula below). The Garmin calculated it at 1625.

And how do we know the PT is right and the Garmin wrong?
The PT measures actually energy expended in Kilojoules. 4.18 KJ = 1 calorie. However, given a cyclists efficiency in converting dietary calires to energy at the hub, the relationship is closer to 1 to 1.

Lab tests show the efficiency is between .18 and.24, which means that calories expended is actually between 1.05 and 1.15 x KJ.

Using kJ x 1.1 =Calories means you'll be accurate within plus or minus 5%. (which is what I used for the PT calories) So even a 5% varience in the PT calculation would still leave the Garmin data off almost 100% high

http://www.saris.com/CalorieCalculator.aspx

So if you're calculating you calorie replacement needs off your Garmin, you might not be losing too much weight."

link to the thread, if anyone is interested: http://www.bikeforums.net/archive/index.php/t-461424.html

Only the Garmin 405cx and the Garmin 310xt use actual heart rate and fitness level to calculate calorie burn. All the other Garmin devices use a calculation based strictly on miles, weight, and height, which would account for the massive offset you see from the 705.

katt742

"it uses temperature, galvanic skin response (sweat) and motion sensors to estimate how many calories you're burning "


That's interesting to know, and now that I look back over my activity manager, I see that it doesn't log HR at all. I wonder if I knew that at one point and just forgot it while the BB was hiding out lost in my house for 2 years, LMAO!

Grumble. Maybe my next purchase is going to be a PowerTap. Why's it so damn hard to accurately estimate how many calories someone is burning? >=o(

I was going to say that my friend has the BB and she says it does everything BUT measure HR. I want to know my HR so I went with a HRM instead...I think that HR is the most accurate way to go...I think...lol.