Does anyone know whether the treadmill or Nike+ is more accurate?
I ran on the treadmill at the gym yesterday and used my Nike+ chip as backup for tracking my time and distance. Nike told me that I went .21 further than the treadmill did, with my average pace being 8:34 and my best mile being 8:24, while my treadmill mile was 10:26.
I ran until I hit a mile on the treadmill just to be sure that I actually completed the distance I wanted – if I went a little further, great. However, I am unsure which device is more accurate than the other. Because I am training for another 5k (and hopefully something bigger down the road), my times are important to me!
I’d like to think that Nike+ is more accurate (obviously I would LIKE that), not only because my mile is better but because my time is more in line with other runs I have done. The day before yesterday I ran outside using the chip and it told me that my pace was 8:48 per mile. I have also done other runs using MapMyRun and GPS, and the Nike times are closer to those than the treadmill is.
Now, I am POSITIVE that I was running faster yesterday (treadmill) than I was the day before (outside). This leads me to believe that between my Nike+ and MapMyRun data, the apps are more accurate than the treadmill. But how can I be sure?
Has anyone else experienced this, or have any insight as to which is more trustworthy? I understand that treadmills are calibrated to measure your speed and distance using the belt and that Nike uses the sensor to calculate your stride, but I don’t understand how there could be such a large difference. My brothers who are both runners have always told me that your time on foot will always be better than on a treadmill, but I wasn’t expecting this!