Start standing with your feet hip-width apart. Bend both arms so that your fists are at your armpits. Your chest should be lifted and your abs pulled in toward your spine.
Jump both feet out to the sides and land lightly while simultaneously driving both arms into the air.
Jump your feet back in to hip-width apart as you lower your hands back to your chest.
This counts as one rep. Complete as many reps as you can with proper form for 40 seconds, followed by a 10-second rest.