Henry Cavill has never been afraid of a challenge.

The British actor, known for his ripped physique in Man of Steel, spends hours training for his physically demanding roles. But the 38-year-old says he didn’t discover his love for the gym until later in life. “When I was in school I played sports,” he tells PEOPLE. “I wasn’t the most spectacular physical specimen back then, but I definitely had drive.”

That drive helped him land his first major physical role in Immortals. “I was doing a lot of martial arts and bodyweight exercises because it was apt for the character,” he says. “And the first time I really moved into lifting weights properly was for Man of Steel.”

From there, says Cavill, his fitness journey took shape. “It’s evolved and developed in its own way depending on the characters that I’ve played or what I’ve had access to — the facilities, where I’ve wanted to go with my body and what I’ve wanted to do.”

These days, he says, he likes to maintain a baseline level of fitness that can be adjusted depending on his work. “I will do a lot of body building work for an aesthetic look for a project or a role,” he says, adding that he focuses on different body parts on different days.

Cavill’s fitness came to a halt in December after injuring his hamstring while working on The Witcher. While some people suffer a mental blow when injured, the Justice League star chose not to see it as a setback.

“When I look back, I realize, yes, it was a hard time,” he says. “I think one of the skills I’ve picked up over the years is just forging ahead regardless of difficulty or hard work or trials and tribulations. So when the hamstring injury came, I tried to look at the silver lining. It was like, ‘Ok. I was working insane hours and it was exhausting and I now physically can’t work because I’m on crutches.’ So I was focusing more on taking the time off and going, how can I best heal myself?”

He explains further. “When it comes to my mental health, [I] focus on what I can control and work on that. And that gives me something to work towards rather than something to deal with or work through or manage my life through.”

With the injury now behind him and no immediate roles coming up, Cavill is working on sprinting. “I want to build a better engine,” says Cavill, who has partnered with MuscleTech supplement company. “One of the things my physical therapy for my hamstring showed me was that I have a lot of capacity in my engine but I have not accessed it. And it’s something which I really want to build upon.”

Nutrition plays a big role in this endeavor.

“Fuel is extremely important,” says Cavill, MuscleTech’s Chief Creative Director and Global Brand Ambassador. Over the years he has learned what works for him — and it works so well that he eats nearly the same thing every day.

“My diet at the moment is more maintenance because I don’t have any shirtless scenes coming up,” he explains, before listing his daily intake:

“Breakfast is a scoop and a half of 100-percent grass-fed whey protein with a cup and a half of oats and berries blended with water, plus a two-egg omelette with two turkey rashers and 4 ounces of beef filet.”

“Three hours later I’ll have 6 ounces of chicken breast with white rice, and three hours after that, another 6 ounces of chicken breast with brown rice. Three hours after that I’ll have 5 ounces of filet of beef with sweet potato.” Before bed, he’ll have another protein shake.

He also allows himself one cheat meal a week. “It all depends on location and what I’m feeling. One of the great things about cheat meals is that you’ll probably be thinking about it for a week and once you get there, it’ll be an excited order of a pizza or Indian food or it will be a Sunday roast which I’ll cook to make an event out of it.”

Cavill admits that mental health plays a huge role in his overall wellness.

“I’ve been dabbling in stoicism. I like some of the core tenets: Don’t let that what you can’t control affect you, don’t let it affect your mental state. Only worry about the things that you can control.”

The message complements MuscleTech’s new “Strength Redefined” campaign, which is redefining what it means to show strength through the accomplishments of everyday individuals, including first responders.

“We have all the necessary ingredients within us to become whatever we wish to become,” says Cavill. “We have that strength, we have that resilience. And it’s just about keying into those necessary ingredients and then utilizing them to intentionally create a physical self as well.”