You really don't need a lot of upper body strength for rock climbing. At least not until you start getting to the really hard stuff. That's really just a misconception a lot of people have. It's really much more about balance and knowing how to move your weight around.

I always got a lot more satisfaction from doing a long, but fairly easy, 5.6 route up some peak in the Sierras than an 80' 5.11 route at the local crag. I love the peace and serenity of the big mountains. There's absolutely nothing like smoking a joint 500' up on a rock wall with nothing but the birds and the wind around you. You just have to make sure that you, and the guys your with, can keep their wits about them when they're high.

As for Friendowl's question about how strong the anchors are; they can hold a lot of weight. Typically several thousdand lbs. The gear isn't what you need to worry about. The rock itself will usually break before the anchors do.