There are three planes of motion in a good golf swing, but this is the one you should be focusing on

There are a lot of pretty swings in professional golf, but the guy in the photo (above) has one of the best. If you don't recognize him, it's 2010 British Open champion Louis Oosthuizen. The South African, now on the LIV Golf tour, has been acknowledged for years for his smooth and stylish swing.

We bring this up because, unlike many tour pros, Oosthuizen has a key move in his golf swing that is much easier for average golfers to copy than those of many of his peers. What is it? Oosthuizen makes a noticeable lateral shift toward the target as he swings down from the top. While many average players struggle with the rotational and vertical components of a quality swing, this lateral shift isn't nearly as difficult to achieve. Even better, it can be trained and enhanced in the gym, says Golf Digest Certified Fitness Trainer Matt Arentz, who works with golfers at his gym, ArentzRX Golf, in Napa, Calif.

Arentz is going to give you exercises and one swing drill you can do to make this lateral shift even better. But first, let's review what it means to correctly shift laterally in the downswing—like Oosthuizen.

Here is a sequence of him as he swings down from the top (below). Note the space between his legs and what you can see in the distance. As Oosthuizen starts down with the club, his body shifts toward the target quite a bit. You can see a tree appear between his legs that wasn't there at the top. This is both a power move and a way to shallow the club onto the correct swing plane.

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You might not be able to rotate your hips fast and forceably as Rory McIlroy, or push off the ground like Bryson DeChambeau, but Arentz says he's found his clients can shift fairly well and should do more lateral training in the gym to boost that aspect of their golf swing.

"Many golfers are missing out on the benefits of frontal-plane training," he says. "If you go through your regular exercises and categorize each by its primary plane of motion, odds are you’ll find you are training almost entirely in the sagittal plane (squats, chest presses, bicep curls, etc). And if you’re a golfer with social media, you’ve probably added some golfy looking transverse/rotational plane movements as well. While the sagittal and transverse planes are incredibly important, we have to make sure we don’t neglect frontal-plane exercises."

According to Arentz, here are the benefits:

• Lateral movement in the frontal plane allows you to load our trail leg, then shift our weight to load the lead leg.

• Getting stronger in the frontal plane can improve lateral stability, which helps absorb force throughout the swing and prevent excessive swaying or sliding.

• Lateral stability can help reduce the risk of injury if motion is limited in another plane of motion.

• Frontal-plane torque provides the ability to shift weight from the trail side to lead side, opening the door for more horizontal-plane torque (rotation) and greater swing speed.

Here are Arentz' two exercises and his swing drill to improve this facet of the golf swing. Do multiple reps of each, training in each direction. In the case of the dumbbell exericse, start light and increase the load as you improve the movement pattern and get stronger.

Dumbbell lateral lunges

Golf club lateral shifts and reaches

Lateral step and speed swings