Kickboxing is a full-contact combat sport and a form of boxing based on punching and kicking. It combines cardio and strength training, toning muscles while burning fat. Kickboxing is not only great for your mind and body, but it also has a very practical usage as a means to learn self-defense. If there's any single quality that separates kickboxing from other cardio workouts, it's that it's—to put it simply—so much fun. It's the perfect form of cardio because you are constantly pushing yourself, typically working with a trainer one-on-one to motivate you throughout your session.