Kettlebells make a great addition to any workout for two reasons. First, they give you that strong, balanced physique that you and your clients have always sought. Second, a kettlebell exercise combines strength training and cardio, so you can get more accomplished in your workout in less time. And in case you need another reason to add a kettlebell to your workout, maybe this will help: Research shows with a little help from kettlebells, you can burn up to 50 percent more calories than your average strength-training workout. Ready to get started?