I’ve been testing the Polar S625X Running Computer that includes a heart rate monitior and a Polar S1 Foot Pod that measures the speed and distance that you run. In my first test, I ran 5 kilometers as measured by my Garmin Forerunner 201, an GPS-based outdoor exercise computer that’s also useful for running.
At the end of the run, the distance displayed by the Forerunner 201 was 3.16 miles while the Polar S625X showed 3.57 miles [ see the photo ]. I’ve run and cycled enough with the Forerunner 201 to know that I’m satisfied with the accuracy of the distances it measures, so I decided to calibrate the Polar S625X using the “manual calibration” method discussed in the Polar S625X user manual on page B38.
The manual calibration method is probably the best way to calibrate the Polar S625X in the middle of the winter, since the “calibration by running method” requires you to run a measured course of at least a quarter of a mile (about 400 meters) and many outdoor tracks in this part of the United States are buried under a foot or more of snow this week.
All I needed to do to perform a manual calibration was enter the ratio between the “actual” distance run and the distance measured by the Polar S625X. That ratio is 3160 / 3570 x 1000 or 885. I entered “885” on the Polar S625X display in the field for the calibration factor.
In my next test, I will probably repeat the 5 kilometer run with both the Polar S625X and the Garmin Forerunner 201 to see if the calibrated S625X measures the distance run almost exactly as the Forerunner 201 does.