A method is disclosed involving receiving GPS data from a personal portable training device. A smoothing operation is performed on the GPS data to generate a more accurate representation of the route travelled for display to a user (504). In the smoothing operation, a cubic spine algorithm is used to obtain an initial estimate of the route representation (500). The estimate is then subjected to a refinement using at least received user motion data recorded by the personal training device (502). In addition one or more of: data indicative of the GPS accuracy; historical route data; and digital map data, such as building footprints and bodies of water, may be used in refining the estimate.