jivnrfarzu'e fu'ivla

x1 (mass/set) do orienteering in competition of type x2 [property of the event] with (other) rule(s) x3 [property of each participant].

The x2 is the major type of the orienteering event, be it Score-O, point-to-point, or other types such as MountainBike-O, etc. The x3 is a property of the individual participants, including things like "not allowed to go beyond point X" or "beating up other participants is allowed" etc. The tanru "jivnrfarzu'e se gunma" is sufficient to say "I do orienteering".