“There’s never an end moment where you say: ‘We’ve rehearsed, and this is exactly how we’re going to play.’ It’s a constant journey.”

The Boston Globe

To much of the world, Andris Nelsons is known as a globe-trotting conductor, avirtuoso interpreter of orchestral works with dual posts at the Boston Symphony Orchestra and Leipzig’s Gewandhaus Orchestra.

But to a small cadre of martial artists in Central Square, he’s known for something else entirely: the board-crushing side kick that helped earn him a second-degree black belt in April.

Nelsons, 45, has been an avid student of taekwondo sincepicking it up again during thepandemic. He stretches each morning, works on his kicks, and practices a series of systematic movements, known as poomsae, wherever he has space, be it his dressing room in Leipzig or the empty stage at Symphony Hall.

But the core of Nelsons’ training takes place across the Charles River at C.W. Taekwondo at Boston, where the conductor arrived by chauffeured car recently for a session with head instructor Dan Chuang.

Trading his street clothes for a crisp white uniform, Nelsons quickly dropped into a full split. He practiced a series of kicks, his feet slapping in staccato bursts against Chuang’s kick pads. Then, in a flourish worthy of aTanglewood crescendo, he spun in a circle, snapping a 1-inch-thick board with his heel.

“I thought it was a prank call,” said Chuang. “But with Andris, he came into the first lesson and he was all out. He’s really serious.”

Perhaps that’s not surprising. Leading an orchestra through a three-hour performance is not for the faint of heart. It demands extremefocus, stamina, and athleticism, qualities that don’t simply vanish when the final note is struck.

The famously balletic Seiji Ozawa, who led the BSO for nearly three decades, is said to have maintained a grueling athleticschedule that included ample tennis and swimming during summers at Tanglewood. Marie Jacquot, chief conductor designate of the Royal Danish Theatre, was poised to become a professional tennis player before she gave it up for music. Meanwhile, Lorenzo Viotti, the chiseled chief conductor of the Netherlands Philharmonic Orchestra and the Dutch National Opera, described his rigorous training regimen for a shirtless cover spread in the Dutch edition of Men’s Health magazine a few years back.

Denise Lotufo, a physical therapist and cellist with the Longwood Symphony Orchestra, compares professional musicians to elite athletes.

“They’re constantly moving,” said Lotufo, who added that cross-training can not only improve performance but also extend a career. “You’re trying to keep your body in balance.”

For Marta Gardolińska, music director of the French Opéra National de Lorraine, that’s meant a vigorous off-podium routine that includes running, swimming, and yoga.

“We don’t really have an instrument, we just have our bodies,” said Gardolińska, who was advised to pursue professional sports while she was also training as a musician. “You need to express with your hands, your breath, your face. Maintaining a healthy instrument ultimately is what sports and music is for.”

The results seem to pay dividends, with many conductors living (and performing) well into their 80s and 90s. Ozawa, frail but determined, conducted from time to time until he was 87; he died earlier this year at 88. Cellist and conductor Pablo Casals died at 96, while Herbert Blomstedt, 97, is scheduled to perform at Symphony Hall in February despite a fall late last year.

Retired conductor David Dworkin, 90, attributes his continued good health to his physicality on the podium. Dworkin’s gone so far as to craft a workout routine known as Conductorcise, which is exactly what it sounds like.

“The motions stimulate brain and body,” said Dworkin, who also cycles every day. “It’s a natural thing: You put a baton in somebody’s hand and they move, they move parts of their body they’ve never moved before.”

Nelsons, who studied martial arts as an adolescent in his native Latvia, rediscovered taekwondo while hunkering down with family in Germany during the lockdowns. He started with instructional videos on YouTube, eventually graduating to a boxing dummy he placed in the garden.

“I needed to concentrate my energy and fill this hole created by the coronavirus,” he said. “I bought gloves and started to kick.”

By the time Symphony Hall reopened in fall 2021, Nelsons was hooked. He googled Boston-area studios and discovered C.W. Taekwondo, a nonprofit operation with lots of high-caliber instructors and students.

In the years since, Nelsons has trained exclusively at the Central Square studio, having the BSO’s driver, Peppino V. Natale, ferry him across the river five times a week whenever he’s in town.

“Strongest maestro in the world!” Natale called out while waiting by the car for Nelsons towrap up. “Second-degree black belt. … It’s no joke.”

As he’s moved upthrough the ranks, Nelsons has become friendly with some of his classmates, inviting a group to a concert last year. More recently, he’s been training privately with Chuang, who described Nelsons as “probably top 1 percent” in terms of flexibility for his age.

“What has impressed me most about Andris is that he is so persistent, and he’s very thoughtful,” said Chuang. “He really thinks about the things that we’ve worked on.”

To illustrate the point, the coach pulls out his phone to show two videos from Nelsons’ latest black belt test. In one, the conductor breaks four stacked boards with the aforementioned side kick. In the other, he uses a spinning hook kick to extinguish a candle.

“His aptitude is not elite-athlete level for all things,” said Chuang, 49. “But in some ways, I would argue that he is elite-athlete level in his growth mind-set and his ability to persist through challenges.”

Among those challenges is staying fit while leading an international career, regularly skipping time zones and eating out at restaurants.

Taekwondo is “healthy, with cardio, sweating, a full-body workout,” he said.

He also likes the belt system and the calming effect of the poomsae, the choreographed set of offensive and defensive movements that become more complex as a student advances through the belts.

“I somehow have learned to calm down with this kind of meditative feeling of poomsae and breathing,” said Nelsons, who comparedthe movements to the unfolding of a musical performance. “There’s never an end moment where you say: ‘We’ve rehearsed, and this is exactly how we’re going to play.’ It’s a constant journey.”

He added that taekwondo’s discipline, from putting on the uniform to staying loose but present while training, carries over into his work as a conductor.

“We use the power of the right moment, while in the meantime being relaxed,” said Nelsons. “That kind of practice is what you need for an instrument.”

Chuang, who worked for years as an engineer, said that while it was initially exciting to train with a public figure like Nelsons, he likely would have scaled back his teaching if the conductor weren’t so committed. Instead, they’ve formed what he called a “partnership and friendship through these activities.”

Even so, the taekwondo master had never seen the maestro perform with the BSO until a visit to Symphony Hall last May.

Now he’s hooked.

“My mother turned 80 this year, and her request is to go to Tanglewood,” said Chuang. “It’s on my list.”

Photo: SUZANNE KREITER/GLOBE STAFF