LOS ANGELES — Nicholas Hoult laced up his black Adidas sneakers, grabbed an orange jump rope and found a spot in the alleyway behind Trinity Boxing Club, a no-frills gym behind Melrose Boulevard in Los Angeles.
It was an early Wednesday morning, and the light was still soft. As the rope whistled under and over him in one seamless motion, Mr. Hoult appeared to hover in the air like a gorgeous human hummingbird.
“Beautiful,” said Eddie Arrazola, his trainer. “I train a lot of actors, and a lot of them don’t pick it up, but Nick actually knows how to box.” Mr. Hoult batted off the compliment with a shake of his head.
After the 10-minute warm-up, Mr. Hoult bounced inside the boxing club, which smelled like old leather and stale sweat. The gym resembled a set from a movie, its black walls plastered in rah-rah quotes from great men of history handwritten on canvas panels.
Which was his favorite? Mr. Hoult pointed to an epigram attributed (mistakenly) to Winston Churchill: “Success is Never Final.”
Mr. Hoult, 29, appears to be a man of some humility. At the age of 12, he worried that his career had plateaued.
He had just starred opposite Hugh Grant and Toni Collette in the funny, whimsical movie “About a Boy,” and was back home in Wokingham, the genteel market town in southern England where he spent chunks of his early childhood running around the garden and emulating the Lost Boys in “Hook.”
“It’s an odd thing at that age — to think, ‘In this career I may well have peaked,’” Mr. Hoult said.
He wriggled a boxing glove over each hand and strode up to the ring. Reggaeton was playing over the sound system, and Mr. Hoult’s body seemed to sway gently with the rhythm.
That his career did not evaporate after “About a Boy” was in part thanks to some bold choices, including a role in the risqué British high school series “Skins” and a well-received performance in Tom Ford’s 2009 debut, “A Single Man” — “an important homosexual film,” wrote former New York City Mayor Ed Koch in a review for The Atlantic.
Although important homosexual films have become a résumé staple for emerging stars, it was less common a decade ago. When Mr. Hoult flew to Los Angeles to meet with Mr. Ford for dinner, Mr. Hoult had no idea who Mr. Ford was.
“I did an IMDB search and he just came up in ‘Zoolander’ as himself, and I thought, Interesting, he’s gone from that to writing this script.” He wrinkled his face. “In hindsight, I should have done a Google,” he added.
After a series of supporting roles, including in “The Favourite” and the “X-Men” franchise, he now stars in “Tolkien,” playing the title role in a drama about the early life of J.R.R. Tolkien. Tolkien lost some of his closest friends in the World War I, and the film depicts the tendrils of his opus, “Lord of the Rings,” emerging from the mud and trauma of the trenches.
For his research, Mr. Hoult listened to Dan Carlin’s “Hardcore History” podcast. “It starts off with him asking who has most influenced 20th-century history, and the answer is Gavrilo Princip,” he said. “It’s really good if you have a spare 30 hours.”
Mr. Hoult moved easily in the ring, ducking and countering in fluid, graceful gestures. “It’s muscle memory,” he said, humbly. When Mr. Arrazola shouted “jab,” his arm extended and retracted with a quick one-two beat. “What you want to do is set your body up to where you don’t have to think anymore,” Mr. Arrazola said.
It was Daniel Kaluuya, Mr. Hoult’s co-star on “Skins,” who first got him into the boxing ring, when Mr. Kaluuya was training for a role in Roy Williams’s boxing play, “Sucker Punch,” at the Royal Court Theater in London. “There’s a lot of technicality and beauty in the sport,” Mr. Hoult said. “It’s very difficult physically, but I don’t enjoy, particularly, going to the gym because your mind wanders.”
In the ring, the mind is too busy avoiding punches to wander far. Has he ever delivered a sucker punch? Mr. Hoult shook his head quickly. “It’s easy to hit a bag and feel you’re a great boxer, but it’s a different thing when someone is actually tapping you back,” he said.
Mr. Arrazola said: “He says that, but his punches say otherwise. He hits pretty hard.” Not for nothing, perhaps, had Mr. Kaluuya bestowed him with the nickname “Headshot Hoult.”
Although boxing appeals to a lot of actors, Mr. Arrazola said many struggle to master it. “They do a workout and then look at themselves in the mirror,” he said. “Nick just wanted to learn right away.”
Mr. Hoult bobbed his head left and right, moving through various punches on Mr. Arrazola’s command: jab, left hook, uppercut. A light sweat varnished Mr. Hoult’s face. “I have quite an obsessive nature about things,” he said. “In my head, I think I want to be the best boxer that I can be.” He laughed. “So silly.”
The two men circled in the ring. “Nick has a really good hook to the body,” Mr. Arrazola said. He arced his fist through the air. Mr. Hoult slid nimbly under it.
As they trained, they compared favorite boxers. “Lomachenko,” Mr. Arrazola said, referring to Vasyl Lomachenko, the two-time Olympic gold medalist from Ukraine. Mr. Hoult gave an obliging nod. “Pretty amazing to watch,” he said. “I like Tyson Fury a lot.”
After about 40 minutes, Mr. Arrazola held up his mitt for a final flurry of jabs and cuts from his student. Mr. Hoult unwound the boxing bandages from his hands. “I’d love to do a boxing movie, if the right one came along,” he said. Like every other actor, he reveres “Raging Bull,” and also “Rocky.”
As he packed his gloves, he said, “You can’t not love ‘Rocky.’”