sign up for cross-training races to hone your skills . . .
There is no better way to train for an adventure race than to focus on each discipline individually!
Participate in focused events such as orienteering, trail running (trekking), mountain biking, paddling (kayaking) and the elusive rappeling (ropes).
Don't neglect discipline focus, especially in weaker sports that can be strengthened.
There are many local race directors who put on several events throughout the year that complement adventure racing schedules.