How does it determine when I take a "step" or "climb a stair"?

[Choreo]

I tried my new FitBit HR at the gym last night and was trying tio figure out how it knows:

(1) When I take a step and

(2) How it knows the difference between a "step" and a "stair"?

I found that walking around the gym it was very accurate. So then I tried walking in-place taking large steps and it showed no new steps. I then tried swinging my arms while walking in-place and it did log those as "steps". So I am "guessing" that it is somehow sensing the movement of my FitBit attached arm past my heart from front to back to log a "step"... is that right?

I then ran up and down 4 sets of 14 stairs at the gym and it logged "4". So apparently it somehow only counts going "up" stairs - how does it know the difference? And how does it know when a "step" also counts as a "stair"?

I then jumped on to an automated "stepper" at the gym and climbed 40 steps and it did not log ANY stairs climbed - is that because my arms were stationery on the machine?

I finally jumped on a AMD (elliptical stepper) machine which is mostly a "steeping action" with arms moving, but again showed "steps", but no "stairs" climbed.

Can someone clarify how it determines a "step" and a "stair"?

[betpchem]

The "stair" is counted by altitude. That's why the stepper didn't get you any stairs, and running up and down the stairs only counted "up."

I think each time you climb a stair, it counts as a step. I've always assumed that anyway. Steps are done by movement. Certainly moving your arm will sometimes give you false steps. I jog in place all the time and it counts those for me. I would guess when you walked in place you were going to slowly to register as movement. This happens to me if I'm proctoring a test in the classroom. I'm trying to walk quietly so as not to disturb the students, and it just isn't enough movement.

Welcome to Fitbit and the forums!

[SunsetRunner · Accepted solution]

@Choreo as @betpchem noted your Fitbit Charge HR calculates a step by one swing of the arm front and back. You can sometimes get a step with your arm not moving but I have found it is less accurate without arm movement like a normal step motion. And Fitbit's calculate "stairs" as a rise in elevation equivalent to 10'. This is measured by an altimeter in the tracker that senses air pressure and when a change in air pressure equivalent to 10' gain in elevation is detected it counts as 1 flight of stairs. Fitbit only calculates stairs walked up, you don't get credit for going down a flight of stairs.  Also since Fitbit uses an altimeter based on air pressure you can get false stairs from a few things such as: an incoming storm that changes the barometric pressure around you, walking outside and it is windy, having a desk fan (or any other type of fan) blow at you, or being around a HVAC vent having that blow air at you.

[Choreo · Accepted solution]

"Altimeter" makes sense. If that is the case, that would also explain why last night at the gym I did 2,500 steps on the "Stair Climber" and it shows only "steps" and no "stairs climbed" as there was no change in altitude!

[gjohnson323]

I also hate when you walk around in a grocery store for an hour with your hand on the shopping cart, it doesn't measure any steps!  Better off either pushing with one hand and swinging the fitbit arm OR, put the fitbit on your ankle! 

[Heybales]

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@gjohnson323 wrote:

I also hate when you walk around in a grocery store for an hour with your hand on the shopping cart, it doesn't measure any steps!  Better off either pushing with one hand and swinging the fitbit arm OR, put the fitbit on your ankle! 

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You can also hang it from your body/belt something. Considering many of the early units were purely on-body not on-wrist (unless you bought a 3rd party holder) - they'll see step impacts just fine - but grocery store shuffle is always hard.

But since there are settings to try to accurately count step impacts despite the swing of the arm (dominate arm, ect), those can be muffled somewhat.