Probably there isn't any lapdata in the gpx file. If you upload or post a link to the gpx file then i'll take a look inside the file and see what happens.

regards
Dirk

Your .gpx file contains only 1 trekseg element. So there aren't more laps.
You downloaded the gpx from runkeeper. I imported an activity with 2 laps from garmin training center to runkeeper (both as .tcx and .gpx) and afterwards exported that activity from runkeeper. Runkeeper doesn't export lap info in their gpx or kml files. But in runkeeper i didn't see the original lap info at all. So maybe runkeeper deletes the lap info at import.

Runkeeper suggests there are laps/splits at every km or mile (depending on your settings), but that aren't the real laps in my case.

So if you want to have laps, you have to do an enhancement request to runkeeper. In which you ask to download either the original lap info or the virtual lap info (eg. every km or mile)

the gpx format is a world wide described format when using this format you have to validate it against a xsd. See in your file in the top lines. So when using a description of a waypoint as lap-marker you brake the interface. And when every site does something different, the gpx format loses its use as standard gps exchange format.

If users wants to have lap info in gpx files when using mytracks, runkeeper or whatever other phone app, they have to ask the app-builder(s) for it. When there are a lot of them, at some time in the future the option will be build in the app(s).

As a workarround, maybe some sitebuilders like Stuart here could build an add lap option. For instance sporttracks has an option to show every km next to recorded laps.