The kettlebell is an effective, bell-shaped piece of equipment that will help you build some major muscles. The kettlebell is your ticket to faster fitness, even for beginners. Packing the same weighty punch as dumbbells, and well-suited to the heart rate-spiking benefits of HIIT, these weights develop power, endurance, muscle and strength simultaneously for heavyweight results. And since they're compact, adaptable and versatile, the kettlebell is an ideal bit of kit for the home workout warrior.