Dumbbell side plank with rear fly

Start by lying on your side with your legs extended and stacked on top of each other. Place your forearm on the ground directly below your shoulder, keeping your elbow bent at a 90-degree angle. Hold a dumbbell in your top hand, with your arm extended straight down towards the ground. Engage your core and lift your hips off the ground, creating a straight line from your head to your heels. While maintaining the side plank position, lift the dumbbell up towards the ceiling, squeezing your shoulder blades together. Lower the dumbbell back down to the starting position. Repeat for the desired number of repetitions, then switch sides.