Develop the muscles in your legs and arms while you exercise on a upright exercise bike. If you notch up the resistance to high enough levels you can enjoy anaerobic exercise that stimulates your muscle fibers. Blow off your stress by getting active and making your brain produce your natural inner drug. With endorphins dancing in your brain you get to forget the negative actions of the day. Some people choose to exercise on a upright while swinging a pair of dumbbells in the air. You can do the same without the dumbbells on a dual recumbent bike. Use double action to your advantage by getting your complete body progressively toned in your workouts.