Kettlebell Swing
Stand with a slightly wider than shoulder-width stance and hold a kettlebell in both hands. With the trunk braced forcefully, hinge at the hips while bending the knees slightly to push the kettlebell back through the legs.
At the end of the motion, extend the hips and knees together forcefully to open back to a standing position as quickly as possible. Allow the kettlebell to swing forward and up at the end of long, relaxed arms—the arms should not be actively lifting the kettlebell, but simply connecting it to the hips.
As the kettlebell reaches the top of the swing, allow it to change directions and swing back down, hinging at the hips again to allow it to swing back between the legs to load the next rep.
Notes
Despite occasional claims, the kettlebell swing is not a model for extension in the pull of the snatch or clean and should not be confused for or used to teach it.
See this video for more.
Purpose
The kettlebell swing is a simple way to train explosive hip extension, and also provides good glute and isometric back work. Its use by weightlifters should be cautious, however, as the hip extension is isolated from leg drive against the ground and consequently oriented horizontally—this can create bad habits and interfere with proper snatch and clean technique if that technique isn’t yet well-established in a given lifter.
Programming
The kettlebell swing should be done toward the end of a training session along with other trunk and accessory work. It can be done for huge ranges of reps, from heavy sets of 5-10, to lighter sets as high as 100. Generally, at least for weightlifters, sets of 10-20 are typicall most appropriate.
Variations
The two primary variations of the swing are the tradition/Russian and overhead/American. The traditional swing is appropriate for most applications. The overhead style can be employed if the swing is being used for conditioning. The athlete can also actively accelerate the KB down from the top of the swing to increase the intensity of the loading of the back swing, or have a partner push it down to achieve the same effect.