I figured that my Nike+ plus has slipped in it’s accuracy lately. Today, before I left work, I used Google Earth to measure out 5K on my route along the Mississippi River. It seems that I’m a bit short of 5K as I have suspected from my last few runs this month. I only plotted out what 2.5K was from my starting point, which is what I planned to use to calibrate my Nike+ sensor. It turns out that the maximum distance I can set to calibrate is 1.25 miles. Since I didn’t know where 1.25 miles from my starting point is, I couldn’t calibrate it. I did however end up running the full 5K that I plotted out. I ended up running it in 31’15” which is closer to what I expect for not running since November. I’m going to plot out a shorter calibration route before I run on Wednesday.