Stand upright with your legs together, arms at your sides. Bend your knees slightly, and jump into the air. As you jump, spread your legs to be about shoulder-width apart. Stretch your arms out and over your head. Jump back to starting position.

Get into a plank position, making sure to distribute your weight evenly between your hands and your toes. Check your form—your hands should be about shoulder-width apart, back flat, abs engaged, and head in alignment. Pull your right knee into your chest as far as you can.
Switch legs, pulling on...

Start in a squat position with your knees bent, back straight, and your feet about shoulder-width apart. Lower your hands to the floor in front of you so they’re just inside your feet. With your weight on your hands, kick your feet back so you’re on your hands and toes, and in a pushup position. ...

Simply jog in place!

Stand tall with your feet about hip-to-shoulder-width apart and your arms at your sides. Looking straight ahead, open your chest, and engage your core muscles. Begin by bringing your right knee toward your chest, slightly above waist level. Quickly lower your right leg and left hand.