I have a recumbent, and when my wife wants to ride we go out on our upright tandem. We also go to the YMCA's spinning classes on Mon, Wed, and Fri which are followed by an Abs class then a sculpting. All the various exercise routines lead to a common goal, improve one's overall fitness.

If you cannot make any of the classes the Y offers, I would recommend not spending all your time on the recumbent. Change it up and mix in the treadmill and the eliptical. Upper body weight work and abdominal workouts will help also.