## Is there a way to track calories of a workout with heart rate monitor?

1372 Views 11 Replies Latest reply: Apr 27, 2013 1:09 PM by Kenichi Watanabe
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Apr 25, 2013 7:40 PM

I got a polar heart monitor and like how it tracks my HR during runs. However, I am wondering if there's  a way to track my calories burnt doing something like circuit training.

iPod nano, 7th gen
• Level 7 (30,005 points)

When I use the Nike+iPod kit with my nano when I do my runs, calories is one of the numbers calculated.

For the 7th gen nano, I believe the Nike+ features are built in (you don't need to buy a separate sensor and recevier), so I think it should calculate calories burned.

• Level 7 (30,005 points)

The calories calculation is just an estimate, and it needs something to "count" that is based on movement.  A pedometer can count steps and estimate calories burned based on your weight (and the assumption that each step burns X calories).  Measuring your heart rate does not provide enough information about how you are moving, so I do not think it could provide an accurate result for calories burned.

• Level 7 (30,005 points)

It's just common sense to me.  Someone who is in great shape will be burning X calories at a certain heart rate, doing whatever amount of physical activity.  Someone who is in poor shape will have a certain heart rate, while doing less physical activity, and therefore burning fewer calories.  The simple device cannot know you (as an individual) at such a deep level, to base an estimate on calories using just your heart ratee

My iPod just asks for my weight and height, and uses that as the basis for estimating calories burned.  I could be a fat couch potato or an NFL pro linebacker.  That is not enough information to calculate an accurate calories number, based on heart rate alone.  There has to be a component in the exercise that counts predictable and consistent physical movement.  Taking a step while running or walking IS something the device can count, and provide a reasonably accurate calories number.

Then why is this heart rate monitor able to be used to calculate calories if I buy a watch which syncs with it?

I think you answered your own question.  It can do it IF you buy the watch device, but not without the watch device.  The heart rate monitor can provide a calories estimate IF the watch device provides it with something that it is counting during the exercise.  For example, if the watch has GPS, it can provide the distance you traveled.

• Level 7 (30,005 points)

Yes, it can do it, IF the exercise is something that counts a repetitive and predictable action, such as taking steps or traveling a distance, or maybe moving some part of the body in a repetitive and predictable motion.  That is the what a "calorie" is, by definition.  A unit of energy expended to perform a specifc amount of work.  To move a specific body weight a particular distanace is work that can be reasonably estimated as calories, without HR.

If my HR is 80 when sitting for an hour at my computer, I'm not burning that many calories (just enough for moving my fingers and hands, thinking, and general life support).  If an elite marathon runner's HR is 80 when running 10 miles in one hour, that is A LOT of calories burned.  The height and weight is irrelevant, it could be the same for those two people.  The device would not know the difference.  So HOW can it provide a non-bogus estimate of calories burned based ONLY on HR?

• Level 7 (30,005 points)

That's not my point.  My point is that every person is different, and in different physical condition.  It takes more physical activity to get someone who is in better shape to a higher HR, compared to someone who is out of shape.  More physical activity means more calories burned, even if HR is the same for those two persons.  Also, people are just different, and have different HR.  Tennis player Bjorn Borg was well-known for having a very low HR.

A device that measures HR cannot know the difference in the physical activity taking place, unless it is ALSO measuring or counting that physical activity in some way, and if it does that, the HR data is just FYI info - It's not even needed to make the calories-burned estimate.

That "calculator" makes A LOT of assumptions, based solely on height and weight (and your own assumption about what your "average heart rate").  It's precisely because Apple is NOT inept that they do not provide a calories estimate that is likely to be bogus.  Don't you think they would add a bit of simple code to their software (like that "calculator"), if they could do it and provide a useful result?

• Level 7 (30,005 points)

So, let's say you are in great shape and you can do 60 reps per minute of whatever exercise to achieve a certain HR.  Someone else, who has the same weight, is in poor shape can do 30 reps per minute and achieves the same HR.  Calorie is a unit that measures energy expended.  You are doing much more work (per minute) than the other person, and expending more energy, even though HR is the same.  How can a simple device know the difference, based solely on body weight?  It can't.  Any estimate "calculated" is for some make-believe "average person."  You are an unique person.

However, that calculated calorie number may be useful for you, to use as an individual, for comparison between workouts.  So. I'll give you a "win" for that...    But it wouldn't really be accurate to call that unit of measure a "calorie" for comparison with other people; it would be more of a comparative number, so you can track improvement in your personal fitness level over time.

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