Fit Bit Stride Length

26 Aug

Mine is elusive.  It’s a difficult thing to figure out anyway.  Then, mine varies depending on location (treadmill, path, all-weather track), speed, and ???  Who knows what else.  The point is, who can figure this out?  And who can do it so its consistent and accurate?

I made an attempt.  And it may be a poor one, and it’s only accurate some of the time, but this is as good as it gets, without professional input.  Here’s the equation I found online:

(63360 inches * mile) divided by # steps = average stride (in inches) divided by 12 = avg stride (feet)

The accumulation of data:

We walked down the bicycle trail by our apartment, noting the FitBit milage, then watching the FitBit until it said an exact mile had passed.  We walked away from the apartment at my pace, and my FitBit got to my mile before Cool’s (though we walked the distance together).

My Pace:

L- 1 mile in 14 min (4.3 mph pace)= 1722 steps

C- 1 mile in 16 min (3.8 mph pace)= 2063 steps

The discrepancy is probably the stride length we had previously programmed in our individual FitBits.  Still, things got weirder on the way home.  You would think the walk back would put us at approximately our apartment.  Nope, at Cool’s pace mine took me past our start point.  Cool’s took us down a rabbit hole making us walk far, far past our apartment before registering 1 mile.

Cool’s Pace:

L-  1 mile in 20 min (3.0 mph pace)= 2330 steps

C- 1 mile in 41 min (1.5 mph pace)=4931 steps

I don’t know either.  But obviously something is terribly wrong.  At any rate, with those numbers that put stride length (using the above formula) and recorded as mine(my pace), mine(at Cool’s pace) etc at:

L(L)-36.7″

L(C)-26.7″

C(L)-29.6″

C(C)-12.7″

For my average walking pace as 2 feet 6.4 inches and Cool’s crazy average walking pace as 1 foot 7.6 inches.  Which despite the huge problems in milage does seem in the ballpark.

My running stride length was even more complicated, because I ran a single lap in the various lanes (of slight distance variations, due to the circle).  Then, I ran a continuous mile to see if it made a difference.  And I walked around the track to confirm my walking pace on a known distance.  Of course all of those distances occurred at different speeds.  So I got rough averages.

Lanes:  Using (63360)(miles)/# steps

–>the IAAF has standardized track lanes that are 1.22 meters wide.

lane 8 = 453.66 m = 0.2835 mi

lane 7 = 446 m = 0.2786 mi

lane 6 = 433.38 m = 0.2709 mi

lane 5 =  430.66 m = 0.2692 mi

lane 4 = 423 m = 0.2644 mi

lane 3 = 415.33 m = 0.2596 mi

lane 2 = 407.67 m = 0.2548 mi

lane 1 = 400 m = 0.25 mi

Speed Counts:

 In a 9 min/mi, I take 1540 steps

In a 7:50 min/mi I only take 1326 steps

My average stride length for walking (using 5 laps) = 2 ft 3.1 in

Distance Counts:

My average stride length for 1 lap (out of 7 different laps) = 3 ft 4.4 in

My average mile stride (for 5 different miles) = 3 ft 4.5 in

Anyway, that’s a lot of math to say that the Fit Bit isn’t going to give me exact distances, because there are too many variable involved to keep an accurate stride length over a whole day’s distance/speed/elevation/etc. . .

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