Week One, Day 2
About the exercise
Plank jacks can be an excellent warm-up exercise and a stand alone abs and core strengthening exercise. It is great at warming up and strengthening not only your core muscles, but also your legs and arms muscles. This and many other exercises are part of our free workout program.
Exercise instructions
30 seconds on, 20 seconds off, x2.
Place feet shoulders width apart.
Engage your core and don’t let your hips sink down toward the floor.