The Kettlebell Swing is a powerhouse of an exercise that trains and corrects many weaknesses commonly found in the modern human.
This exercise primarily targets the glutes and lower back via the all-important hip hinge pattern.
Mastery of this movement pattern is what allows athletes to utilize the full power of their glutes during explosive movements like jumping.
You also cannot perform this exercise without a major contribution from your core.
A loose core makes for a sloppy, un-explosive Kettlebell Swing and puts unneeded stress on your spine.
Keep your core tight throughout the exercise as if bracing for a punch. This will train your core to transfer energy from your lower half into your upper half.
- See above video