Starting on the hands and knees, keep a flat back and engage the core. Raise the left leg straight back, stopping when the foot is hip-level and the thigh parallel to the floor. Balance for as long as possible, then raise the bottom right toe off the floor, tightening the butt, back, and abs (try to be graceful here!). Hold for up to 10 seconds, then switch legs.
In a high plank position—palms flat on the floor beneath your shoulders, arms straight. Ease down on to your left forearm. Then, ease down your right arm until you’re in a forearm plank. Now push up with your right hand and then your left to return to a high plank. Repeat, alternating which side you lower first with each rep.” Lagree recommends doing two sets of ten reps. Another workout worth trying: these 9 resistance band exercises that will work your entire body.