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Q: What algorithm is used by apple watch to compute active calories

I am having a great deal of trouble finding the answer to the simple question: What are the algorithms used by apple watch to compute active calories?

A useful secondary question is: What is the scientific rationale for those algorithms? 

This is crucial information to know the accuracy of the estimates provided by the watch.

 

Have any exercise physiology labs tested the watch and published their comparisons?

Thanks

-Chris

MacBook Pro, OS X Mavericks (10.9.5), 128K Mac to 3GHz 8 Core Mac Pro

Posted on Sep 14, 2015 6:36 AM

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Q: What algorithm is used by apple watch to compute active calories

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  • by John Galt,

    John Galt John Galt Sep 14, 2015 9:12 AM in response to csl
    Level 8 (48,628 points)
    Mac OS X
    Sep 14, 2015 9:12 AM in response to csl

    Apple has never publicly discussed any specific algorithms and is not likely to do so.

     

    One can only assume such algorithms exist and take into account all the information you or your Watch provides, specifically age, sex, weight, heart rate, environmental conditions, motion and orientation detection, and the type of exercise being performed.

     

    Some time ago, Apple was said to have hired a number of experts in human physiology who were presumably involved in its design. I am not aware of any published scientific test results regarding its estimates. All I can say is that they appear to be reasonable estimates based on my experience with it over several months.