What muscle groups are primarily toned during step aerobics classes?

The primary muscle groups toned during step aerobics classes are the leg muscles. Step aerobics involves performing various movements on and off a bench or step platform, which requires significant engagement from the lower body. These movements primarily target the quadriceps, hamstrings, glutes, and calves. The stepping motions create resistance against gravity, leading to muscle toning and strength development in these areas.

While core muscles may also be engaged to maintain balance and stability during the exercises, the primary focus and most substantial toning effects occur in the legs. Upper body muscles are generally not the main focus in step aerobics, as the exercises predominantly emphasize leg movements. Thus, the emphasis on leg muscle engagement is what makes this option the correct one.