Stand with your feet together and hands on your hips. This is the start position. Bend your knees slightly, then straighten and push through the balls of your feet, jumping your legs apart to wider than hip width. As you do so, raise both arms out and up in a smooth arc until your hands meet above your head. As you return to the ground, bring your feet together and your hands back to your sides with your arms fully extended. Repeat without pause until the required number or reps (or time) have been completed.