What Muscles do Kettlebell Swings use?

The kettlebell swing is a staple exercise of CrossFit training or everyday strength and conditioning work; one that places great demands on the muscles of our posterior chain. More specifically, a study submitted through the British Journal of Sports medicine in 2013 noted that kettlebell swings use predominately hamstring muscles, however they actually target semitendinosus, the medial, inner hamstring over the lateral biceps femoris, with higher levels of Electromyographic (EMG) activity noted through the skeletal muscles.

In general, the kettlebell swing is one of the best exercises for building stability and power endurance through the deep muscles of the spine as well as strengthening our posterior chain.  There are three basic types of swings, the two-handed swings, Russian and American, and the one-armed swing. For the purposes of this blog piece we are going to look at comparing the American and Russian swings.

There are a couple of injury issues concerning the American swing. The close grip, overhead position of the American swing compromises both shoulder stability and mobility. This compromise in mobility will often lead to compensations being made, generally the over extension of the lumbar and thoracic spine. The close grip also places the shoulder in a vulnerable position and could lead to  AC joint impingement, where the head of the humerus impinges or traps the rotator cuff tendons onto the acromion at the top of the swing.

If your goal is to become a competitive Crossfitter, American swings should be the main focus for the specific preparatory and the competition phases of your training (pre-comp and in-comp seasons).  I would, however, make the argument that heavy Russian swings during the general preparatory phase will provide greater benefits across a wider range of movements. 

If you’re not a competitive Crossfitter, and you use Crossfit training to improve your chosen sport’s performance then the Russian swing would be the one I recommend. The Russian swing has all of the benefits of the American swing, with out the risks to shoulder and spine health. 

In conclusion, the Russians have been swinging kettlebells for more then 200 years, if going overhead was better then reaching chest level, surely they would be swinging it overhead. If you do want to take kettlebells overhead, try learning the kettlebell snatch.