Total body training, use a climbing wall.

Moving around on all the holds for two minutes, is a workout on an over hanging wall like this, 45degrees. Do 4 sets of two minutes 3 days a week and you can stay fit and do well on your local crag. As long as it's not Rifle, for Rifle you have to stay on the climbing wall 4 minutes, times 4 sets.

Technique, is  keep your hips up on the wall and keep your shoulder blades pulled back. You want to try to avoid sagging or rounding your back.