1. From a face-down position on the floor, place your elbows directly underneath your shoulders, keeping them bent at a 90-degree angle, with your forearms extended out ahead
2. Extend your legs out behind you, and place your feet hip-width apart
3. When ready, elevate your body into the plank position, with only your toes/balls of your feet, elbows, forearms and hands touching the floor
4. Maintain a strong, straight back with your head and neck in a neutral position
5. Hop your feet to a point wider than your shoulder before hopping them back to the hip-width distance
The primary muscles used in Plank Jacks are the Abs. The secondary muscles used are the Glutes.