Kettlebell workouts are designed to employ the entire body, working many muscle groups at once. That's part of the appeal for using kettlebells. You're working the entire body with the exercises, instead of only targeting one or two muscle groups. Kettlebells exercises include all over body movement, but the main muscle groups that are involved and that are strengthened the most with the basic kettlebell swing motion are the hamstrings, glutes, quads and abs. Bottom line? You get more impact in less time!