You could raise your heart rate by running on a treadmill or build muscle tone by lifting weights. Or you could combine both and add boosting endurance, increasing agility, and burning more calories to the list through CrossBox classes. A blend of boxing and cross-training, CrossBox combines a variety of exercises such as heavy bag work, jumping roping, plyometrics, and kettlebell swings to give members a full-body workout in less time than it takes to complete a 5K or sign up for a 5K.