The plank jack is a great cardio move; it raises the heart rate while working both your lower and upper body.
- Begin in plank position, with your shoulders over your wrists, your body in one straight line, and your feet together.
- Like the motion of a jumping jack, jump your legs wide, then back together. Jump as quickly as you want, but keep your pelvis steady, and don't let your booty rise toward the ceiling.
- Continue plank jacks for 30 seconds.