AvgCadencePosition is related to cycling devices that can determine rider position (Seated/Standing).
It is an array that is indexed based on RiderPosition.Seated/RiderPosition.Standing and will provide the AverageCadence for each position.
AvgFractionalCadence is used if a device supports calculating a Fractional Cadence value. The true average cadence will then be:
AvgCadence + AvgFractionalCadence.
