"Generally speaking, all exercise bikes will work the same muscles. While some bikes come with light dumbells used for upper body exercises during your ride, the act of cycling will primarily target your quadriceps, hamstrings, glutes, and calves," explains Karp. Upright and indoor cycling bikes also require a posture that engages your back and core muscles effectively. And any time you alternate between standing up and sitting in the saddle, you engage your glutes as well.