B. PLANK JACK
Areas trained: CORE, SIDES Technique:
Start in plank position on your elbows with your body in a straight line from head to heel, and your core and shoulder blades engaged.
Keeping your body as still as possible, jump your feet out to just wider than shoulder-width.
Jump them together, then repeat. SAFETY TIP: Keep your hips in line with the rest of your body throughout