Paul Rudd is revealing the secret ingredient to staying youthful.

The actor, who stars on the March cover of Men’s Health, told the publication that sleep is the key to looking young, adding that he sleeps for eight hours every night.

“People ask me, ‘Can you send me your meal plan? How many times a week do you work out? Do you drink? Do you eat carbs? Do you have a cheat day?’ The most important part of training is sleep,” Rudd shared.

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He quickly shot down the theory that trading more hours of sleep for more training time equals better results.

“They’re doing themselves a disservice,” Rudd said of people who practice that theory and therefore get less than eight hours of sleep per night.

The 53-year-old even detailed his morning routine, which begins, first thing, with cardio and a cup of coffee.

“I do cardio before I eat anything,” he said. “I never would’ve done that before [‘Ant-Man’].”

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Rudd, who stars as Ant-Man in the Marvel Studios film franchise, admits that portraying a superhero was not something he ever intended to do, but it’s certainly changed his life.

“I never really thought I was the type of actor that they would offer any of those parts to,” he told the magazine. “But when this idea came around, I was excited about doing something that was so out of left field, and I knew that if it was announced that I was going to be joining a superhero franchise, most people would say, What the f**k?”

To prepare for the role, Rudd recalled hiring trainers and setting a routine that involved lifting weights and cutting out sugar.

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“I’ve learned so much about how my body reacts to foods, how it reacts to exercise, and where I’m happiest and how much it affects me mentally,” he said. “If I’m in this suit, running around playing a character who’s supposed to be a superhero, I just feel better. And I feel less like an impostor.”

“I finally understand if you make fitness a part of your lifestyle, you’ll just feel good,” he added.

Rudd, who was named People‘s Sexiest Man Alive in 2021, is currently filming season three of Hulu’s “Only Murders in the Building”.