Sit upright on a stable chair with your feet flat on the floor and a pair of dumbbells in hand. Let your arms hang at your side and rotate your palms so they are facing forward. Raise your arms straight out to the side until the dumbbells are at shoulder-height. Slowly return them back down to the start and repeat.
We love these adjustable dumbbells from Rep Fitness. They take up very little space and are also very durable compared to other adjustable dumbbells on the market.