My son is a teenager with spastic diplegia. He uses crutches for longer distances, but doesn't need them in the house. He has good stamina and can walk a couple of miles at a time. His physical therapist believes that exercise is good for him, so he walks, goes to the gym, does treadmill and ellipse, etc. It really helps his balance and keeps him from getting tired as easily. I read a lot of people on this site who seem to be having trouble as they age. I'm curious about how that ties in with the long-term effects of exercise for a person with CP. Has exercise helped you to maintain your mobility? Can it be too stressful on your joints and muscles? Have you had good results with exercise? What sorts of exercise have been helpful/hurtful? Do you wish you had exercised more? What do your doctors and PTs recommend?

I exercise 6-7 days a week. For me it's all about keeping the functionality I have without going overboard and hurting myself. It's kind of a fine line.
I usually do the eliptical for 30 minutes-an hour (except right now I am really out of shape and max out at 20 minutes). I stick with that one because swinging my arms like I do while running on a treadmil causes my shoulders to spasm.
Then I do about 15-20 minutes of stretching, abs and push ups. The stretching is really important right after a lot of cardio.
After that I do resistance exercises on alternating days with arms and legs. My advice here would be to get your son a personal trainer for a few sessions so they can show him how to safely use the machines and recommend exercises that will work best with his disability.