[fozentusic]

I run mostly on a treadmill. I'm getting wildly different numbers on the treadmill display than on my Nike+ pod/iphone. I run between 5-6.5mph.

Yesterday's run:
iphone: 6.41km, 35:47, Average pace: 5'34"
treadmill: 2.5 miles, 35:47, Average speed: 5.1mph

I thought it was odd so I went and calibrated my shoe pod again by measuring out 1km on mapmyrun, verified it with my car odometer, and ran it with the Nike+ on. 1km, 6:52

Today's run:
iphone: 5.14km, 29:19, Average page: 5'41"
treadmill: 2.4 miles, 29:19, average speed: 5.3mph

Which one would you believe more? I'm more inclined to believe the Nike+ since it is actually measuring ME not the treadmill (in the same way you can actually be going faster than your car spedometer if you're coasting down a hill), but it means that I've been going faster and farther than I thought I was, so I'm in disbelief.

Help!! Which do I trust?

[juliana77]

Could your stride be a different length on the treadmill? I have no idea how you could verify this, but it seems that a tiny difference could really add up.