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DESMOSCOLEX
03-26-2010, 11:22 AM
I've just started some interval running training (mixing walking and running) as a way to get into running. I'm running on a treadmill indoors using a 405 and a footpod. I have not calibrated the footpod yet as I wanted to see how close the two were (treadmill and footpod) but have decided to now calibrate it. I haven't done the calibration test but it seems that it doesn't give a consistent error between the two (and I've tried it on two different treadmills). When I'm walking the footpod records a lower speed than the treadmill (up to 0.7mph at 3mph according to treadmill) but when I'm running it records a higher speed (0.7-1.3mph at 5mph) . I assumed that this was because it assumed a constant stride length but I was taking longer than expected strides when walking but have just read on the forums that the footpod should take this into account.

I'm tempted to calibrate it at my normal running speed and accept it will be inaccurate at other speeds but has anyone got any comments or suggestions?

Just looked at my data and if a calibration factor of 1000 means 100% accuracy and 1050 means the footpod is recording 5% slower than it should then my calibration factors would be ~1080 at 3mph and ~850 at 5mph.

t_smit
03-26-2010, 12:45 PM
Unless you have a specific reason for wanting the footpod readings to match your treadmill, it would be better to calibrate the footpod outside. You can do this automatically using the GPS signal as a reference, or you can do it by running a known distance, i.e. at a track.

The reason for doing this is that your gait on the treadmill will not be the same as it is outside, and generally speaking you'll be more interested in instantaneous speed or cadence information outside, since you don't have the treamill controlling how fast you go.