Full Plank with Arm Circle
Start in full plank position. Keeping hips parallel to the ground, alternate making a big circle with each arm. Start by sending your arm forward, then up and back along the side of your body. Tips for a strong plank: Hands and feet should be shoulder width apart, with wrists, elbows and shoulders are aligned. Keep core and glutes engaged throughout - this helps keep your back from sinking toward the ground.