Dumbbells are used to exercise all major muscle groups including arms chest back abs legs and core. The benefits of dumbbell exercises include muscle building improving core strength boosting balance providing better bone health burning calories increasing energy levels enhancing overall mood and more. Dumbbells are perfect for training individual muscle groups or major muscle groups HIIT workouts and walking. Built for durability safety and comfort the CAP Neoprene Coated Dumbbell Weights have an iron core made from ASTM A48 Grade 20 grey iron and are then precision dipped in 3mm of neoprene.