There's a big difference between personal recreation and recreation which is done for the benefit of others. Even in the least structured of all styles of outdoor trips, the common adventure trip, outdoor program staff are burden with the responsibility of helping guide democratic process within groups. Democracy even within small groups is never easy, and dealing with personality conflicts within the unsettling environment of the outdoors can be and is wearing. When you're doing it every weekend, it's work. What is at the heart of the matter is an emotional commitment to the job and the participants.
Some trips go smoothly, of course.
But others are different. Like a raft with a slow leak, an outdoor staff person staggers home at the end of emotionally demanding trips, flaccid and deflated. Often the next morning they'll be back the office, cleaning up the van, putting away gear and tying up the loose ends. Throw several of these trips together, and with time, burn-out enters the picture and quietly does its damage. The cure, of course, is time off.