Last night I got to the Lowry Hotel in Manchester quite late after spending the day in Warwick. As a consequence I didn't get to go running until 9pm. Not knowing Manchester that well I decided to jump on the treadmill in the gym rather than getting lost. This gave me the chance to calibrate the Nike +. In retrospect, it looks like I have been underestimating the distance I have been running by around 15%. The newly machine calibrated system should allow me to set a new 5k benchmark when I am feeling fresher.