How Zendaya’s ‘Challengers’ Co-Star Mike Faist Beefed up to Play a Tennis Phenom

Brad Gilbert, the tennis coach who's trained Coco Gauff and Andy Murray, spoke with Variety about coaching Zendaya’s Challengers co-star, Mike Faist, for Luca Guadagnino’s sports-world thriller.

Challengers stars Faist and Josh O’Connor as two tennis stars and former best friends, now bitter rivals, who go head-to-head in a challenger’s match after falling out over their shared pursuit of an enigmatic coach (Zendaya).

Faist had to embark on a calorie-heavy diet in order to add the proper bulk needed to play tennis phenom Art Donaldson. Having recently come off a singing-and-dancing role in Steven Spielberg’s West Side Story, the regimen represented a sharp shift in Faist’s lifestyle.

“Mike had to eat between 8,000 to 10,000 calories a day because they wanted him to gain weight,” Gilbert told Variety. “He was coming off West Side Story, and he was super thin. He had to work on his tennis and gain like 30 pounds. I had Zendaya in Los Angeles, so we got her on a program right away, and Josh was working, so [Faist] had the latest start.”

As Faist’s character is the only one in the film who has a signature playing style, Gilbert sought inspiration from the game of real-life tennis stars to craft Donaldson’s play.

“Mike’s character was built on that classic Roger Federer and Pete Sampras play,” Gilbert explained. “He’s supposed to have a big serve and a one-handed backhand, so we had more of an idea with his game.”

Gilbert had only nice things to say about the rest of the Challengers cast. “They are all incredibly dedicated and professional,” he said of Faist, Zendaya, and O’Connor.

Challengers is in cinemas now. The Amazon MGM release is poised to gross a respectable $12–15 million over the weekend and topple Civil War from the top spot at the box office.