Rafael Nadal adjusted his bottles. Goran Ivanišević watched Teletubbies. Maria Sharapova turned her back on her opponents. Tennis has always been a sport with such quirky pre-match rituals, and now, Carlos Alcaraz has kept the tradition going. After reaching the semifinals of the Indian Wells Open, Alcaraz finally revealed the curious reason behind his pre-match juggling ritual.

At the post-match press conference, reporters asked about his habit of juggling tennis balls during warm-ups. The Spanish star explained that the routine actually came from his physiotherapist, Juanjo Moreno.

“It’s because my physio told me to do it. And I just obey, obey him (smiling). So I don’t know if it’s helpful or not, but I took it as a routine. Everything went well since I started to do it, so why sort of change. So I just keep it like that, and if my physio says it or I need to do it, I just, I’m gonna do it, for sure,” Alcaraz said.

Later in the press conference, Alcaraz was asked when the juggling habit began. “A couple of years ago. Yeah, a couple of years ago from now.”

The juggling ritual has appeared in several public moments. One notable example came during the summer of 2024. It happened during the first week of tennis at the Olympic Games in Paris.

In the viral clip, Alcaraz stood inside a busy hallway at Roland Garros. He calmly juggled three tennis balls while players and staff walked around him. The young star moved slightly from side to side, focused entirely on the rhythm.

It was not the first time cameras caught him doing it. Several videos online show the same routine before matches. In some clips, Alcaraz and Moreno pass the tennis balls back and forth in a steady pattern.

The idea behind juggling seems simple at first glance. It helps sharpen hand-eye coordination before stepping onto the court. For a professional tennis player, that skill is essential.

However, scientists believe the benefits may go deeper than that. Studies suggest juggling can stimulate the brain in complex ways. Researchers say it may even trigger neuroplasticity.

Neuroplasticity refers to the brain’s ability to adapt and change. Repetitive coordination exercises can create structural changes. That process may strengthen neural connections over time.

One researcher who studied the activity is Noah Cowan from Johns Hopkins University. He believes juggling activates multiple sensory systems in the body. “It sort of really engages your whole sensory motor apparatus in a very complete way,” Cowan explained.

Researchers also point to how the brain processes touch and movement. These signals stimulate the central nervous system. The experience can resemble the feeling of a tennis ball hitting a racket.

Studies also examine the structure of the brain itself. The human brain contains gray matter and white matter. Both play critical roles in how the brain functions.

Gray matter supports memory, movement, and emotional control. White matter connects different regions of the brain and allows communication between them. Research shows that juggling can increase gray matter in areas related to visual processing and anticipation.

Another study discovered changes in white matter as well. Practicing juggling for about 30 minutes per day over six weeks improved motor-function areas of the brain. The improvement even affected peripheral vision.

Today, Alcaraz is not the only tennis player using this routine. Several top players follow similar coordination drills before matches. What looks like a simple trick may actually be a powerful tool for preparation.

Jannik Sinner weighs in on the juggling trend

Alongside Carlos Alcaraz, his chief rival, Jannik Sinner also enjoyed a strong run at the Indian Wells Open. The Italian star moved smoothly through the early rounds of the tournament. In the quarterfinals, Sinner faced the 25th seed Learner Tien. The Italian handled the challenge well and secured his place in the semifinals.

After that win, Sinner spoke with reporters during his post-match press conference. Among the questions was one about juggling tennis balls during warm-ups. The topic has gained attention after similar routines by several players.

Sinner confirmed that he sometimes practices juggling as part of his preparation. “Yeah, I mean, we try to mix it up. I know how to juggle, but I do normal warmups. Everywhere it’s different. I saw some players, they do a lot of playing and juggling. Me, depends how I feel before the match,” Sinner said.

The juggling routine has also gained popularity among players on the women’s tour. One example involves young Russian star Mirra Andreeva. She once shared a story about seeing Alcaraz perform the drill.

In 2025 at the Italian Open in Rome, Andreeva defeated Linda Noskova 6-1, 7-5. After the match, she was in the locker room with her coach, Spanish legend Conchita Martinez. At that moment, Alcaraz appeared nearby with his team.

Andreeva noticed the Spaniard performing a juggling exercise with his fitness coach, Juanjo Moreno. The drill impressed her immediately. She decided to add the same exercise to her own routine.

“He has some nice exercises. We actually stole one already with Conchita, with juggling the balls. He does this one where he’s juggling three balls and his fitness trainer catches them. We stole that one, but so far that’s the only one so far!” Andreeva shared.

Cameras have also spotted several other players juggling before matches. At the US Open in 2024, TV cameras showed Aryna Sabalenka juggling three tennis balls before her semifinal. Jessica Pegula has also been seen practicing the routine.

The idea is not limited to tennis alone. Even athletes in other sports use similar coordination drills. For example, Stephen Curry of the Golden State Warriors often trains with a tennis ball and a basketball to develop creative dribbling patterns.