In my case (not op) I don't belong to a traditional gym and go rock climbing several times a week. I don't really care to go for a run but I love climbing. Also my knees are in bad shape because I am both tall and heavy which means running/biking/anything where I regularly move my knees hurts. Climbing is nice because most of the time unless I am trying to dyno (jump) to a hold I only use my feet to keep myself against the wall or to statically take my weight while I move my hands.

I guess a better term would be, you are not doing much `aerobic' exercise. High intensity sports like rock climbing or lifting definitely train your cardiovascular system. In a different way than `cardio', of course.

If your goal is to bulk up, then you need to consume more calories than you burn. Cardio burns calories, meaning you need to eat more food to hit that caloric surplus.