Kettlebell training originates from Russia. It involves a very simple, archaic looking piece of equipment. Think of a cannonball with a thick handle attached and you have a good idea of what a kettlebell looks like. They come in various sizes and weights. One might think that this is too simplistic, but let me tell you, it is a highly effective way to train when done properly.
The exercises that can be performed cover all of the usual stuff that can be done with a dumbbell, such as curls, presses, rows, etc. Other exercises that can be done would be the Bent Press and Turkish Get-Up and the list goes on. For the legs you can also perform squats and lunges. There are so many others, just take a look online for examples.
Working with high repetitions is a very good cardio workout that can be achieved by keeping the heart rate at an elevated level. On the flipside, training with heavy weights and low repetitions prove to build muscle and increase strength.
People all over the world are utilizing this type of training and making fantastic gains. Kettlebells are used by many strength and conditioning coaches all over the world to train the best athletes in the world. This type of training is a big favorite among competitors in combat sports such as wrestling, boxing, and mixed martial arts (MMA).
No matter what your fitness goals, consider adding some kettlebell training in your routine. You will not regret it.