T.J. Davenport pulls his way to the top of a 100-foot oak during a recreational tree climbing course at Camp Wyman in Eureka, Mo., last month. Such climbs offer good full-body workouts, advocates say.

What's Your Workout: Tree Climbing Ann Koenig is an urban forester for the Missouri Department of Conservation. In her downtime, she's up in the trees -- as a competitive tree climber.

Rock climbing is exactly what it sounds like. It's an activity where you climb on rocks or mountains outdoors, or on rock climbing walls indoors, for fun, adventure, or exercise. Climbing used to be a ...