With the included s3 stride sensor, the Polar RS800CX Run Heart Rate Monitor tracks your progress with a running index feature and records stride length and cadence. Set this monitor to show pace and cadence for speed training (shorten your stride and work on increasing cadence while holding the same pace). The stride sensor allows for three calibrations for three different pairs of shoes. The altimeter uses barometric readings to show elevation profiles, and the extended exercise profiles allow you to create training sessions with individual settings for duration, heart-rate target zones, interval training, and recovery calculations.