Start with your feet hip width apart then step back with one leg so that all weight is transferred on your forward leg. Bend forward at the knee so that your thigh is parallel to the ground and your abs are pulled in. From here hinge from your hips and let your arms and dumbbells hang from shoulders.
Lie flat on your stomach with your arms out straight in front of you. Keeping your legs and arms straight, lift the opposite arm and leg off of the ground as high as possible, so that only your torso and pelvis are still on the ground. Hold this for a few seconds then switch sides. Do 12-15 reps, 3 sets.
Lie on your stomach with a towel or pillow under your hips. With your hands behind your head, lift your upper body off of the ground as high as possible. Look up at the ceiling at the top of the movement and squeeze your back muscles and glutes tight as you lift your legs. Do 15 reps, 3 sets.