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Calorie count using apple watch fitness app

exxx...

"If you are a senior rider with power, you should be getting wildly different data from your own rides and devices than you are writing about here. I just did a 14.4 calorie/minute ride on my trainer, and I was not pushing it that hard. I have only been riding again since December, so I hope to increase my power dramatically over the next two months. This was not an A-level effort by most people's standards."

Well I get very accurate measurements using these devices:

Cyclops Power Tap
iBike Newton

I'm now 60 years old
Train with Power and back in the day started with perceived fitness and then moved to HR meters before power meters.
The book of rule for Road cyclist is "Training with Power," which backs up my statements.
The measurement of Froome, a two-time winner of the Tour are factual and posted on the web.
I personally use a Computrainer and have done so for since they first came out many many years ago.
I have also been on the podium from racing
I daily use my power, HR, speed and cadence meters.
I was (many decades ago) an approved cycling coach (course given by the Olympic Training Center in COS, although I never participated nor functioned as a coach).

I am currently writing an app for interval and bike training which uses power meters (and reads via BT from the device) as a measurement of effort.

I did not make up what I wrote and the ability to sustain over 200 watts as an average is beyond most recreational road riders.

I'm sorry you don't believe what I write but they are fact.

Wattage measurements without true power measurement are just estimates and are normally way off. The only device which doe not actually measures power without measuring torque of force is the iBike. This is a sophisticated device which uses weight, slope, drag coefficients, acceleration, speed, airspeed and some other metrics to calculate direct wattage and it is very accurate.

Sorry the stuff is true and proven via science.

I might point out there are only a few stationary trainers which are approved or recognized as "accurate" devices for wattage measurements. In general they all cost $800 - $1,500 and one must use their own bike attached to them. The Computrainer and Wahoo trainers are two of them.

Have you heard of the FTP? This is a measure of power capability for a time trial on road bike.
While it is measured in a few ways the typical measurement is the average for a 1 hour time trial on a road bike. Notice Froome did 414 watts in 41 minutes. That's an output of 5.8 watts per KG of weight (he weighs 71 kg). That's in the world class measurement of capability for road riders. a typical local racer would be closer to 340 watts for his FTP (based on 85 kg at Froome's weight it would be 284 watts, all based on numbers from 'Training and Racing with Power').

I don't know what you weigh or where you rank or how fit you really are, but the average person is no where near either Froome or the good local racer, they just don't have the time. So a 200 watt average would be normal for a such a person.

71kg = 156 lbs
85kg = 187 lbs
[doublepost=1454883179][/doublepost]One more response to exxx...

I mentioned in my post that I do not use the AW for any measurements because it was more consumer oriented than serious training. I did make it quite clear that unless the device measures actual wattage, with the exception of the iBike, no device can provide accurate measurements of the wattage used. Even the Computrainer and Wahoo trainers requires a spin down test after 12 minutes to calibrate the device for indoor measurement. If you trainer does not ask for such a moment it probably is using estimates and is probably on the high side.

Based on your 14.4 per minute that means you burned 864 Calories in an hour. Assuming it's Calories (if it's watts then you are a superman) let's back it into an average as we measure it for training. 864 * .24 = 207.36 * 4.18 = 866.7 / 3600 = 241 watt average. This means at any one moment you put out 241 watts of power and based on the book I mentioned and what you weigh you are near the bottom of the racer (not recreational rider) fitness levels.

Again I don't know how fit you are, your age, weight or any other thing but I know this, while not a winner at a time trial you won't be last either. I said the average person can't sustain an effort much above 200 watts.

See wha the numbers are confusing.
 
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bjet767 said:
See wha the numbers are confusing.
Click to expand...
I figured out your error. You just converted average watts into kilojoules, and then you converted kilojoules in to calories (kilocalories). You did not account for the overall efficiency of the system (both bike and rider). When the rider is powering the bike, he is also consuming a great deal of energy that is used internally for cooling as well as pure loss. You do not account for any of that. The power a rider puts on the pedals is a fraction of the total energy the rider is consuming to produce that power. (I am an engineer and dabble in analytics too, so numbers are my forte. That is how I figured out the errors and inconsistencies inside the AW calorie algorithms.)
 
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exxx...

"I figured out your error."

Sorry but it's not an error. This is the way the actual Pro teams do their measurements, it's the way Computrainer shows it, Powertap and iBike shows the direct watts being produced at the moment of measurement.

An athlete's performance in competition is a function of work and the nice part of using a beautiful machine like a bike is it is relatively easy to measure that work. One of the measures of capability is how many watts per kg of weight a rider can produce. And calculating work to calories really is an easy thing, however, calculating a bodies response and actual caloric burn is almost impossible. Onne thing that is known, if you want to lose weight there has to be a modification of caloric intake and if one wants to become fit then work must be done to improve the body's response to effort and that is what training is all about.

There are more metrics based that performance that serious bicyclist use with the basis for "zones" and training is now one's FTP and not HR. Workouts are designed around ones goals and abilities HR is used a a reference for fatigue, dehydration and recovery ability combined with and as a back-up to power/wattage measurements.

There are several coaching services which use the very same metrics, and more, which I have written about. There is even a very good free open-source program called 'Golden Cheetah" for serious self-coached cyclist that take these things into consideration.

But of course this thread is about the AW and is it it accurate compared to many consumer training devices. The answer is maybe, but that is based on the metrics used by AW and the various devices.

No it was not an error.

BTW IT is basically impossible to measure this, "You do not account for any of that. The power a rider puts on the pedals is a fraction of the total energy the rider is consuming to produce that power." and any attempt to is purely an estimate due to the various individual response we all have.

I suggest you look at the iBike device. It has what is probably the most sophisticated algorithm ever used in an exercise device that calculates power output in watts and it is not a direct force measurement. Their accompanying computer program generates same Calorie numbers I have given in these posts.
 
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Your error is not the math, it is the application. The error is in trying to apply the formulas for an elite athlete's equivalent calories of energy produced at the pedal (or crank, or bottom bracket, or hub, etc.) to say that the AW is more accurate than a stair stepper. The root is that you cannot directly equate energy at the pedal to the calories consumed by the human body to produce the energy at the pedal. Additionally, an elite athlete's body is orders of magnitude more efficient than any of us normal people. These comparisons and the mis-application of the formulas within the argument are apples and oranges. You said that you do not use the AW for measurement, so that implies that you have no first-hand experience actually looking at the AW data compared to other tools. Finally, you seem unaware of all the exercise science that has measured calories the human body consumes during various activities and translated those measurements into well-accepted algorithms. Rather than licensing proven calorie consumption algorithms, Apple appears to have written its own.

Edit: A couple more thoughts... One thing that might help is if you could show some comparative data from your rides that lists your total calories burned data from your PowerTap/Newton, your Apple Watch, and ideally another trusted device like a Garmin, if you ride with one. The key is to see how the data line up between devices. The AW works for some, but for many others, it is so far off that it looks like the AW is not even trying to be accurate. In my observations, I have found that the Garmin is relatively close to most other devices for total calorie consumption. However, the AW is so far off that it is not believable. Apple consistently loses by a 2-1 vote.
 
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I do believe the Apple Watch is low in its calorie counting even when it only shows active and then it adds the BMR. However, I do believe many people way over estimate their calorie burn. Many (including myself) are use to stepping on a treadmill or other device and just start moving. The device used doesn't know a thing about you and most people I see using these devices don't input their stats or used a connected heart rate device. Those devices can be way way off.

I did a VO2 test and my VO2 was 33 and the testing started out easy but I was running at 12-15mph at one point and I was exhausted. My calories burned was 125 for 15 minutes and my watch said 101. I am not in horrible shape but I could not run a 6 minute mile for an hour. That calculated me at 800 calories burned but 10 minute miles for an hour at 600. That is for a man who is 6'4 and 215 pounds. And I'm old.

If you use these calculations saying 1000 calories per hour to ride a bike for 1 hour at a 16-mph, it would all depend on the person being monitored. All aspects must be measured and input. Lance Armstrong would burn 300 calories going at that speed for an hour. :)
 
exxx...

I will answer this question, have I used the AW and compared? The answer is yes and if you read my posts rather than attempting to find error you would notice I say it is a consumer device and not for the serious athlete multiple times.

My beef is when compared to the standard fitness equipment used by most people in gyms and home, their data is almost always high and scaled more for the effect than reality. As others point out to accomplish the metrics you keep writing about the device requires a whole lot more information about the user (than age, weight and sex) to figure estimated calories, wattage and other things and it is for this reason the competing community has settled on direct force measurements and a slew of metrics based on them.

I have compared the estimates of unconnected devices to the real numbers and they are off by as much as 2xs (always on the high side). So with the ability to measure actual work produced verses an estimate, why would anyone do something else?

In the end all exercise is good and that is the point of the AW's program and the tracking a persons goals. But if the person wants to train to a personal best or compete for the podium the fitness program of the AW and the read outs of those normal gym trainers fall short. It's not what they are built and written for.

Exercise is good and whatever will motivate a person to do it is really good.

Yes I have my AW on right now. It show me with a resting HR.

;)

PS. You win
 
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bjet767 said:
Exercise is good and whatever will motivate a person to do it is really good.
Click to expand...
I learned a ton from you, and I will be checking into a lot of what you referenced, particularly iBike and some of the training books. I have not raced since the late 80s, and my only bike is my 30 year old road bike. I have been indoors on a trainer since December, riding about 3-5 hours/week. Two weeks ago, I went out on my first real ride in more than 15 years. All of this is really getting me pumped up to get back into it, though not as intensely as before.

I would like to get some kind of power meter for riding outdoors, but it does not make sense until I do a bike upgrade. But, something like the iBike might be the ticket. It may not be as accurate as direct force, but it might be good enough and something I could easily move from my old bike to whatever I end up with.
 
exxxviii said:
I learned a ton from you, and I will be checking into a lot of what you referenced, particularly iBike and some of the training books. I have not raced since the late 80s, and my only bike is my 30 year old road bike. I have been indoors on a trainer since December, riding about 3-5 hours/week. Two weeks ago, I went out on my first real ride in more than 15 years. All of this is really getting me pumped up to get back into it, though not as intensely as before.

I would like to get some kind of power meter for riding outdoors, but it does not make sense until I do a bike upgrade. But, something like the iBike might be the ticket. It may not be as accurate as direct force, but it might be good enough and something I could easily move from my old bike to whatever I end up with.
Click to expand...
I finally upgrade both my watch and iPhone to the latest dev betas and my indoor run workout with the app was about 10-20% higher for the calories even though my average heart rate and speeds were about the same. Maybe just a coincidence but that might be something for others who have been concerned with the calorie burn with the watch.
 
BlueMoon...

One of the things I did not mention in the previous posts about calorie count and accuracy is in the elite cyclist world they attribute 20 - 25 % of the persons effort is not directly converted to force on the pedals. As previously mentioned it is almost impossible to actually measure the amount of calories which really just go up in heat rather real work when a person works out, so all of the devices just make a wag at it. I suspect it is as often higher than 50%, which to me is really too high, but if you are riding a bike I applied 24% to the number so you could actually work it backwards if you are given the calorie count from your device.

In the end it's all about staying healthy and working out in an appropriate way.
 
Apple Health is a reasonably accurate way to track your calories expenditure, because it is based on population averages.
Obviously, depending on your muscle mass, bone mass, etc your true expenditure may differ, but the incorporation of your heart rate make the apple watch a reasonably good way to track your workout calories and the Apple Health which tracks your total active, as well as your resting calories, are a good starting point for those of us wishing to monitor our TDEE to compare to our intake.
 
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