Quadriceps
Calves, Glutes, Hamstrings
Stand facing bench/box.
Place one foot (e.g., right) on bench.
Push off right foot, driving body upward.
Quickly switch feet in mid-air, landing with left foot on bench and right foot on floor.
Immediately push off left foot, switching back.
Continue alternating feet rapidly, mimicking sprinting steps on/off bench.
Use arms for rhythm and balance.