Flabby upper arms are a common issue for several women caused by increasing body fat and smaller muscle mass. With the use of dumbbells, you will target your biceps, triceps as well as shoulders for leaner and firmer arms. Here are easy exercises to get those sculpted, toned arms you dream of. Triceps CurlsHold a dumbbell in each hand facing inward, slightly bend your knees, and keep your feet hip-width apart. Slightly bend your elbows and lift your arms outwards and upwards until they reach shoulder height.