Enlightening, controversial ideas on weight training, diet, exercise, running, biking, home workouts and more. The seat should be padded and adjustable. A bike with moveable handles helps you get a total workout.
Recumbent bikes are good for low back problems.
Stairclimbers with independent foot action give you a better workout. Again, those with arm levers are also very good for increasing intensity. Be sure it is sturdy. There are a wide variety of multigyms. Shop carefully and find the right gym for your needs.