I use it with a Forerunner 910XT. It will give you more accurate information than information through GPS on the pace, cadence but also the distance! (If he is carefully calibrated on an athletics track) This becomes necessary if you realize very tortuous path (many bends) and rolling: Garmin does not thing proclaims from the rooftops: distance calculations (and thus average speeds and gaits) are made in 2D and 3D and not. CaD: if you go from one valley to another with a mountain between two: the projected distance (triangle base) is taken into account instead of the 3D course (2 other sides of the triangle), even with 910 that has a built-in barometer !!! (It is only for reading data derived from altimetry - precisely calibrated if he is - and not to internal calculations). It's the same for the Edge: either you pair a GSC10 sensor is you will have big surprises on a mountainous course. Note: you can choose the GPS records the trace to know where you are past, then that is footpod data used to calculate distance.
