Stand tall with your back straight, abs engaged, shoulders relaxed, arms at your sides, and feet together.
Hop out with both feet while extending your arms out, forming an X with your arms and legs. Hop back in to the starting position (legs together, arms at your sides). Repeat.
Master the Modified Jumping Jacks before trying this movement. Be sure to land softly, keeping the knees slightly bent to reduce impact. Move more quickly to increase the intensity.