Most golfers think power comes from turning the body hard on the downswing so it drags the arms and club through impact. Truth is, that's the weakest way to hit the ball. The most powerful way is to start your arms down and let your body actually stop to create a slinging action at impact. I call it snap speed.
This is not a new concept. The fastest moves you make in everyday life use the speed of your hands and arms. Your body is powerful, but it doesn't accelerate quickly. Distance in golf comes from speed, not force. A tour player's body rotates 7 to 12 miles per hour in the downswing. If you rely on your body turn to make the club move fast, you'll never hit the ball anywhere. Your body has to brake on the downswing so the energy you're creating moves out to the club.
Consider a few examples of acceleration. Snapping a towel comes from your hand stopping, even pulling backward, which sends the speed out to the tip of the towel. To throw a Frisbee, you swing your arm to a dead stop and snap your wrist. Picture a test car running into a cement wall and the crash dummies going through the windshield. In all these actions, there's a braking. That's what puts the energy into the object. If everything kept going forward, there'd be no transfer of speed, no snap. And that's how so many golfers swing.
Zach Johnson, whom I've worked with since 2000, is a great example of snap speed. He's not a long hitter, but he's in the top 10 on tour in a stat called total distance efficiency, which means he optimizes his speed at impact. If you want more distance, you've got to snap it like Zach.