Krav Maga
Last winter I subscribed to CrossFit and downloaded the training guide. Shortly after that I began to order the equipment needed to practice and master the required exercises. On the list of items needed to train was the kettlebell. The kettlebell is used as a weight but it allows you to be more creative with your work out than the dumb bell. The come in many different colors, weights and styles. I purchased a 20lbs kettlebell from Walmart by CAP for $23 and I plan on getting a complete set soon, they range from $100-$500.
Kettlebells increase core stability while allowing you to get a great cardiovascular work-out.