A cast-iron weight shaped like a ball with a handle, used in swinging exercises, is called a kettlebell. Its offset handle and compact, bottom-heavy shape let users perform movements that combine strength, balance, grip work, and cardiovascular conditioning.
The modern kettlebell developed from the Russian girya, a metal weight used in the 18th century, often for weighing crops. Circus strongmen adopted similar weights during the 19th century, and kettlebell training became part of organized strength athletics in Russia and Europe. Competitive kettlebell lifting is commonly dated to 1885.
Kettlebells differ from dumbbells and barbells because the load hangs below the hand rather than being centered directly around it. That design changes leverage during swings, cleans, snatches, and Turkish get-ups. Traditional Russian kettlebells were measured in poods; one pood equals approximately 16.38 kilograms, which helps explain why 16-kilogram kettlebells became a familiar standard in modern training.