Bird Dog Pose

Start on your hands and knees with your palms flat on the floor and shoulder-width apart. Your neck should be in line with your back, and your gaze should be down or slightly forward. Brace your core, and raise your left arm and right leg until they’re in line with your body. Hold for five to 10 seconds, and then return to the starting position. Then repeat on the opposite side (right arm and left leg).

To make this exercise easier: Keep your hands on the floor, and only extend your leg.