I climbed all the time in college and it was a good and fun way to work out. I agree with Stu, as it would best be a way to train strength endurance.
I lot of the good climbers at the gym I climbed at were big, some amateur bodybuilder big, at least in the upper body. They would go work out, then do laps on the wall. Climb up, lower down, climb up, sometimes climb down, then climb up again.
A couple had more mass than you would assume a climber to have, and it made sense they climbed so well because they were all around athletes. That being said, there is an upper limit on BW where you can’t be pretty much doing pull-ups with one or two fingers and expect your tendons to support your bodyweight.
In my opinion, the best way to get a cardio work out with it is steep wall/overhanging bouldering. You have to keep your core tight the whole time, to avoid falling away from the wall, and most of the moves are harder and more sustained than some of the higher, roped routes people set. Bouldering is just climbing lower to the ground without a rope. Theres definitely a mental aspect to it too, where you put yourself in an awkward position where if you fall you probably aren’t going to land controlled, you know if you throw for a higher hold it will probably hurt your fingers, then you have to hang on, control the swing, reset your feet keeping tension the whole time lest your foot slips then your hand slips, then look for the next hold and do it over. Its definitely a pretty intense, total body, strength endurance kind of workout.
I also ripped more skin and callouses off my hand from climbing than from lifting weights, although I’m not deadlifting 500 lbs.
In short, its fun, better than slow cardio, but don’t neglect the weights if you want to get big.
