A quick rundown of what the swing does:
- It trains hip extension, which is the foundation of all athletic movements.
- It stretches the hip flexors and strengthens the glutes. This is especially important when you consider that the entire population is, by evolutionary standards, sedentary. We sit too much. Swings help fix the problems caused by too much sitting down. In fact, a swing could be looked at as the OPPOSITE of sitting down.
- It strengthens the lower back as a stabilizer rather than a dynamic flexor/extender (which could cause deterioration of the discs)
- It teaches the abs to brace against dynamic force making them stronger without creating bad movement patterns (as many conventional ab exercises do)
You'll notice in the list above the one thing I didn't mention was anything about the upper body. Shoulder stability is a side effect of a good swing, not the main focus. My biggest problem with the kettlebell swing, is that as SOON as someone learns the snatch, they substitute swings for snatches.
The problem, I think, stems from the fact that the snatch is technically more difficult to learn initially which makes people think of it as an "advanced" swing -- and everyone is advanced right!?? It's not.
Why you should choose the swing over the snatch in your training:
- You can do more swings at a faster cadence--this means more work for your legs
- You can use a heavier weight.
- Less variables. This is key because it lets you focus on the hip extension (which is the main goal as well as part of a good snatch anyway).