The GPXData schema is an mix-in schema for use with the GPX 1.1 schema from Topografix. It was designed with the intent of expanding GPX (using the existing mechanisms) to contain additional content from GPS receivers commonly used for sporting and geocaching activities. HR represents the heart rate in beats per minute. Cadence represents the cadence in revolutions per minute. Temp represents the temperature in degrees celcius Distance in meters as measured by GPS or wheel sensor Set if there is a sensor present On devices that have the concept of a run, the run encapsulates laps and provides overall summary information Added if there is data available that doesn't have position information Lap is used to contain information about an individual lap of activity. Depending upon the device, this may contain a variety of additional information. Depending upon the device, this may be contained within a run or course. Course is used to contain additional information about a course downloaded to the GPS as a track. Depending on the device, this may be uploaded as part of the data or left empty. Always appears in a track. dataPt is used to store information about non-geographic data point. This is useful when HR or other data is present, but no latitude or longitude data is. The type of sport being participated in The type of program being executed Group of laps that make up the run Index of the course in the GPS. Group of laps that make up the course The index of the lap in the internal list. The starting point of the lap in Lat/Long The ending point of the lap in Lat/Long The starting time of the lap The total elapsed time of the lap in seconds The number of calories burned during the lap Distance (in m) covered during the lap Reference information for the track which corresponds to this lap Performance summary elements summarizing different performance measurements, such as cadence, hr, etc. The trigger of the lap. On some devices, the lap may be manual or automatic based on attributes known by the device. The intensity of the lap (whether resting or active) Index into the referenced track of the point that this lap starts on Index into the referenced track of the point that this lap starts on Reference by number to the track (matches number) Reference by name to the track (matches name)