As a pretty serious rock climber, I would say it definitely is an adrenaline sport. But the adrenaline is just part of it. You also get the sort of runners high from sustained exercise, and another sort of high of "holy shit, I can't believe I just pulled it off" from dealing with challenges in real time and finding solutions.

In comparison, I tried sky diving once and found it, in a weird way, boring. Sure, you get an adrenaline rush - but there is no real physical or mental challenge. You just jump, deploy the chute, and land. When we landed, my heart was definitely pounding, but in a strangely unsatisfying way. I didn't feel like I had really pushed myself or accomplished anything - I was just up there, and now I'm down here. Big whoop.

Skiing here, I’d jump off some stupid stuff if I could afford to get there.