Assessing physical activity levels from accelerometer data

Thread Starter


Joined Nov 13, 2014
I should say at this point that I am clinical in background and my technical knowledge in this area is limited - hence reaching out for support!

I am trying to understand how to use raw x,y,z accelerometer data to assess physical activity levels in METs. My current understanding is that METs can be estimated from total counts per minute using any one of various equations, e.g. Swartz MET Rate = 2.606 + (0.0006863 * CPM) but I'm not sure about how to convert x,y,x data to counts (per epoch).

I have identified the following formula: counts = (x2 + y2 + z2)0.5 (power 0.5) which I believe may be the answer (or at least part of the answer) but after extensive searching on the internet I have yet to find anything definitive.

I would be so grateful if anyone could provide me with any guidance/insight at all in this area or point me to any reliable references.

Many thanks in advance for any help you can provide!


Joined Oct 2, 2009
I suppose you already googled MET accelerometer?

btw, one thread is enough. The others have been deleted.
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