Is Exercise Really Worth It?

I pretty much took off all summer from the gym, and started exercising again last week. This morning I took a class called Body Pump, in which you spend 1 hour and 15 minutes lifting a dumbell over and over and over and over. I'm pretty sure I won't be able to get out of bed tomorrow morning. I also know that they say "No pain, no gain" but I just wish that after almost 2 years of running, lifting, crunching, squatting, and lunging, I had somthing to show for it. Basically what I want is to have the body of the instructor that has been yelling at me to lift, crunch and squat harder. Oh, well! I just keep going and making the other gym-goers feel better about themselves.