Pro pickleball player Julie Johnson shares her go-to drills for the fast-growing sport

Pickleball, a humble hybrid of tennis, ping pong and badminton, is among the fastest-growing sports in the U.S., with 4.8 million people now playing, according to the Sports & Fitness Industry Association.

It is a low-impact, highly social alternative to tennis, says Julie Johnson, one of the world’s top-ranked pro senior women’s singles players.

Here, Ms. Johnson shares her go-to exercises to stay injury-free and at the top of her game.

How: Start on your hands and knees with a flat back. Slowly extend your right arm straight in front of you, in line with your head, and your left leg behind you in line with your hip. Try to maintain a flat back and level hips. Return to start and switch sides. Perform 10 repetitions on each side.

Why: Many pickleball players experience lower-back pain. This exercise strengthens your core, glutes and lower back, while simultaneously working on upper- and lower-body coordination.

Lateral Shuffle to Squat With Band

How: Place a resistance band above your knees. Stand in an athletic stance, with feet hip-width apart, knees and hips slightly bent. Pick up your left foot and push off your right foot as you take small, quick steps to the left.

Your chest should remain tall and spine straight. Hands can be on your hips or clasped in front of you. Shuffle 10 steps, then perform a squat and reverse directions. Complete 10 sets on each side.

Why: Pickleball requires nonstop movement front to back and left to right, but our daily tasks rarely call for prolonged side-to-side movement.

How: Step your left foot in the center of a Bosu ball, flat side down, and your right foot on the ground so you are in an athletic stance with knees slightly bent.

Jump sideways so your right foot lands on the Bosu and your left foot on the ground. Continue to jump side to side, keeping your gaze straight ahead. Slowly increase speed.

Why: This exercise works proprioception, our body’s ability to know where it is in space, while also training single-leg balance.

How: Start in a high-plank pose with your hands slightly wider than your shoulders. Tighten your core as you lower your body until your elbows are at 90-degree angles and your chest is hovering above the floor. Press through your hands and engage your core to press back up. Aim for 10 repetitions.

Why: This classic strength exercise is the foundation of Ms. Johnson’s routine, and she calls it her secret to avoiding injury. Push-ups work all of the muscles that cross the shoulder joint and so much more, she says.

One-Leg Balance With Figure-Eight Arms

How: Stand on one foot. Hold a pickleball and raise it above your head. Trace large figure eights in the air, five in one direction, five in the opposite. Switch feet.

Why: Pickleball is all about coordination, Ms. Johnson says. This exercise trains your body to get used to your upper body doing one thing while your lower body does the opposite, she says.

How: Hold a tennis ball in your dominant hand while balancing on your right leg. Toss the ball against a wall and try to catch it off just one bounce. Perform 10 throws, then switch legs.

Why: This exercise will challenge your balance and coordination while also improving single-leg strength.