Jumping jacks work several muscle groups, promote cardiovascular health through aerobic activity, and are effective as a warm-up prior to more strenuous exercise. They target the shoulder, abdominal and leg muscles. For maximum benefit, the abdominal muscles should be kept tight throughout a set of jumping jacks.
Jumping jacks do not require any special equipment or a large amount of space. The traditional form of this exercise is a high-impact workout component that should be avoided by people with joint problems in the knees, ankles and feet. A modified, low-impact form of the activity eliminates the jumping in favor of a full leg extension, alternating from left to right.