Kettlebells have been around for more than a century. They were used extensively by the performing strongmen of the circuses during the late 1800s. Some strength historians will argue that kettlebells have existed for many centuries, dating back to when the Celts made them from stone. Whatever the case may be, kettlebells are making an amazing comeback in the strength and conditioning of athletes as well as in the everyday fi tness programs of people around the world.