*3.2. Field Study*

Figure 9 shows the MAE of the total running distance for the field study dataset, both for the algorithms and GPS-based estimation. The figure indicates that the *Trajectory* algorithm performed best with a MAE of 94.0 m. The error was comparable to that of the GPS-based estimate (82.1 m).

**Figure 9.** Mean absolute error of the 3.2-km run for the four different algorithms and GPS.
