Stride length differences

Do you do a lot of hiking activities with GPS on? It's just possible that it's adjusted its accelerometer calibration for slow paces during your second activity.

I cannot explain your results, but I can state that my walking stride is all over the map. It varies a lot depending on the day. My running stride is pretty consistent. So .. is it likely that your stride is also not the same from one activity to the next, yes very much so.

Are you wearing the HRM-Run here?
If so is how cadence would be computed in a timed activity.

In any case, if you do a Run activity (and presume a Hike one) without GPS or a foot pod then the pace (and hence distance) is modelled from your arm swing rate and so is only ever going to be approximate.

So the largest difference in steps is 8, and the largest difference in distance is 264 feet. (.05 miles)

If the GPS accuracy for you start and end is "withing 40 feet" (you can't see that value on the 735, but you can on something like an eTrex that provided more sat info), that could account for up to 80 feet right there.

If I wear two GPS watches and record the exact same thing with GPS, I've seen them vary by .01-.02 miles, so that could be another 105 feet.

So out of the 264 foot difference, this could explain 185 feet of it.

It would be interesting to see the same data, but for a longer distance (maybe 2-3 miles), as with this being a fairly short distance, some of the of the things I mentioned could be much more noticeable in the data, where with a longer distance, they make less of an impact.

Are you wearing three devices at the same time, or are the first two the 735 in different modes at different times? Doing separate tests could also account for the difference, unless you take the exact same steps each time.

Do you do a lot of hiking activities with GPS on? It's just possible that it's adjusted its accelerometer calibration for slow paces during your second activity.

No this was the first day. I am using Hiking because there is no Walking activity available. I also tried a Running activity without GPS, and got the same result as Hiking with no GPS - 0.38 miles instead of the 0.42 miles that was measured with GPS.

I cannot explain your results, but I can state that my walking stride is all over the map. It varies a lot depending on the day. My running stride is pretty consistent. So .. is it likely that your stride is also not the same from one activity to the next, yes very much so.

Except that the number of steps is consistent over the 3 trials. So my stride was actually the same. The device used a different stride length for some reason when doing normal activity tracking, than when doing an activity with GPS off.

Are you wearing the HRM-Run here?
If so is how cadence would be computed in a timed activity.

In any case, if you do a Run activity (and presume a Hike one) without GPS or a foot pod then the pace (and hence distance) is modelled from your arm swing rate and so is only ever going to be approximate.

No HRM-Run was used.

I subsequently tested a Run without GPS which gave the same results as Hike without GPS. The distance was short (0.38 instead of 0.42 miles; 0.42 is known by previous experience to be the correct distance).

Do you have more info on this arm swing thing? For instance how the pace is calculated from arm swing? I find it surprising that a different technique is used than is used for normal activity tracking...

So the largest difference in steps is 8, and the largest difference in distance is 264 feet. (.05 miles)

If the GPS accuracy for you start and end is "withing 40 feet" (you can't see that value on the 735, but you can on something like an eTrex that provided more sat info), that could account for up to 80 feet right there.

If I wear two GPS watches and record the exact same thing with GPS, I've seen them vary by .01-.02 miles, so that could be another 105 feet.

So out of the 264 foot difference, this could explain 185 feet of it.

It would be interesting to see the same data, but for a longer distance (maybe 2-3 miles), as with this being a fairly short distance, some of the of the things I mentioned could be much more noticeable in the data, where with a longer distance, they make less of an impact.

Are you wearing three devices at the same time, or are the first two the 735 in different modes at different times? Doing separate tests could also account for the difference, unless you take the exact same steps each time.

I did three trials in succession, and another later in the day. All four trials had step counts between 826 and 834, so consistency was very high. The distance is known to be 0.42 miles.

I think Tim might be on to something, in that the calculation is based on arm swing (somehow) for Activities, and by stride length for normal activity tracking.

Your step count doesn't strike me as high, assuming you're walking. I know for me, I do between 1800 and 2100 per mile, based on my speed.

Your step count doesn't strike me as high, assuming you're walking. I know for me, I do between 1800 and 2100 per mile, based on my speed.

Agree, I wasn't saying the step count was high, I was saying the consistency of step count was very high.