How to perform this exercise
Stand feet shoulder-width apart with kettlebell a foot in front of you. Bend at the waist and grasp kettlebell with both hands.
Pull shoulders down and back and brace core before starting. Maintain this form throughout.
Lift kettlebell off the ground and allow it to swing between your legs. Knees slightly bent. Keep your back flat and neck straight by keeping your eyes on the bell at all times.
Drive hips forward to propel the kettlebell. Control the kettlebell with your arms, but don't pull it up. The kettlebell should travel no higher than your shoulders.
Allow the kettlebell to swing back through your legs. As kettlebell lowers, move fluidly into the next rep.
On final rep, allow it to swing back through your legs, and place a foot in front of you on the ground.
Using your arms
The Kettlebell Swing is a lower-body exercise, not a shoulder exercise. The momentum generated by your hips is enough to swing the kettlebell. Arms only help to control the kettlebell.
Ignoring the core
Loose core = sloppy Kettlebell Swing putting stress on your spine. Keep your core tight. Imagine that your upper body is in a plank position. This keeps your spine in the proper position and makes your glutes, not your lower back, do the majority of work.