For me, it's more of a "safty net." I have a history of arrythmias, and I get nervous doing exercise, for fear of going into v-tach (which I did before surgery, but haven't since, thank goodness). There are nurses monitoring you at all times (hooked up to a heart monitor) and if anything happens, they see it and stop you immediately. At any rate, I'm sure some people, who were active people to beging with, could probably go without rehab and be fine. But I've NEVER been very active because of my heart. I never took a PE class, and really don't know WHAT to do.
Right now, this is my "regimine":
M-W-F "class" set of streaches
1lb weights (5 reps for each type)
6 minutes on stationary bike
4 minutes on airdine (sp?) (works your arms)
6 minutes treadmill
2 "cool down" laps
all other days I am told to walk for 15 minutes (if I can)
I'll admit that right now the "regimine" is pretty easy. They said they will keep working me up (as a matter of fact I did less today than I will on Friday), but want to take it slowly to check my tolerance level. I am also THE youngest person there (that I've seen so far, anyway). I felt a tad out of place today. But no one asked me any questions... yet. I'm sure once I've been there awhile people will start asking. All of the staff knows about me, though. They had fun with my EKG lines (they look WAY different because of my pacemaker and my situs inversus). But they are all very nice.