I started trail running this year and yes lots of 0 streets. I also started working on running hiking club loops at each state park. I notice all those trails have names to them.
I also have 2 big trails near me that were railroads turned trails. One is over 80 miles and I finished running every section of it. Would be cool to get credit for completing it.
In theory it should be possible to include hiking routes if they exist in OSM, to import trails with the right ‘relations’…as an example, a 370km trail here in Portugal called Grande Rota do Zêzere has been coded in OSM. As you can see in the screenshot, part of the trail is a ‘Minor/Unclassified Road’ but a larger portion is an ‘Unmaintained Track Road’. Neither has a name…it sure would be cool to get credit for running/hiking this massive trail for each ‘city’ it runs through! And if relations were added for other smaller trails those could be added too.
tl;dr: trails that don’t have names but that do have relations with the name of the trail could presumably be captured by CityStrides.