An sf-class data.frame with a row per point recorded along a workout route,
originally exported as a gpx file from Apple Health and with data exported
by the extract_gpx3d
function.
gpx_segment
An sf-class data.frame with 501 features and 5 fields:
datetime
elevation (metres)
longitude
latitude
sf-class POINT geometry of lon-lat
units (metres), distance between this point and the previous