I've been getting serious about planning a more thoughtful workout routine with periodization and coordinated focuses on climbing technique, aerobic fitness, and muscular strength/power/endurance. Lately I've been poring books & articles on training, and NONE of them even mention swimming as an aerobic exercise to do. I never really see it discussed with climbing training at all.
These days I usually use swimming as my "outdoor" aerobic workout on rainy days in place of cycling or running. It's very intensive to swim hard for 1 hr straight, and works every muscle in the body, including motions from pulling transitioning to mantels. Of course the resistance is low, but the repetitions wear you down.
Does anyone have any thoughts on swimming for training? Am I best only using it as a 'backup' exercise? Should I do more in the gym (e.g. stairmaster) instead of swimming? Or should I consider phasing in more swimming during some parts of my training for total body awareness, coordination, and endurance?