The Origin Cast Iron 20kg Kettlebells can be added to any weight training programme and are suitable for all fitness levels. However, when added to specialist training such as circuits, they can also help increase endurance, and stamina. Muscle groups targeted through the use of cast iron kettlebells include: biceps, triceps, deltoids, rhomboids, trapezius, lats, quads, glutes and core abdominals. The Origin Cast Iron Kettlebells are entry level pieces of equipment as they are usually made from single moulds. Since the handle is moulded to the body, this style of kettlebell is less suitable for impact based exercises as the joint will undergo an element of stress. A stylish cast iron set of kettlebells, ideal for ballistic exercises and studio training. The form and uniform handle allow these products to stand alone as they are perfectly balanced.