Dumbbells are versatile and easy-to-use weights that help you perform a variety of workouts to improve your health. Depending on the weight you use, the number of repetitions you do and pace at which you use them, dumbbells can help you improve cardiovascular fitness, burn calories, build muscle or increase muscular endurance for sports.
Dumbbells come in different weights, starting with the smaller lightweight types used during aerobic workouts or while using a treadmill or exercise bike. Heavier dumbbells are for body-building.
In sum, dumbbells are good for: building muscles, improving cardio health & blood flow, aid weight loss, improve muscular endurance and bone health