The Suicide Squad actor and WWE star says getting bullied as a kid inspired his passion for strength and fitness

Because John Cena is known for his physical strength and larger-than-life persona, it’s hard to believe that the sizable star ever experienced any bullying, but Cena credits those experiences with inspiring who he is today.

“My passion for strength was out of self-defense. I used to get picked on a lot because I was different in the way I dressed and expressed myself,” Cena, 44, tells PEOPLE in this week’s issue. “As you’re an adolescent, social cliques form and I didn’t fall into any one of those. So I got tired of getting beaten up and I asked my dad for a weight set and he got me one at 13. I started working out and I haven’t stopped since. My quest for strength probably lasted, I don’t know, until my mid-30s. And now I’m on a quest for wellness, which is hopefully so I can continue physical fitness for the next, 30, 40, 50 years of my life.”

Cena’s passion for strength and fitness training led him to a degree in exercise science and kinesiology from Springfield College in Western Mass., and is the backbone for a lot of his current career and his start in the WWE.

“[After college] I headed out to Los Angeles not because of the entertainment allure, but because that’s where the hub of fitness equipment, fitness manufacturing, fitness distribution, everything that applied to my degree was there,” he explains. “I got in working at Gold’s Gym and that was the best I could do.

I worked in the protein shop. I worked on the floor. I knew every member and a bunch of the members would talk about wrestling and WWE specifically. This is right when two companies were jockeying for supremacy, the company owned by Turner and the company owned by Vince McMahon. One of my friends in a casual conversation was like, ‘Hey, we’re training down in Orange County to be wrestlers. Do you want to join?’

Cena decided to give wrestling a try as “a sick ass hobby.”

“It wasn’t like, ‘Yeah, this is my chance to make it big in the WWE,’ it was like, ‘Yo, this would be a sick ass hobby, so when I worked my ass off during the week, I can go be a personality on the weekends, I’ll try it.’ I paid the promoter a bunch of money to get in the ring and learn how to fall down and the rest is history. So if we had never had that conversation, I’d never found a ring, and I’d never been talking to you right now.”

With age and experience, Cena has adjusted his fitness routines to focus more on overall wellness vs. brute physical strength.

“I used to want to be as strong as I could, and that meant being stronger than I’ve ever been in my life. Now, I just want to continue to train. So it’s not that I’m not trying to push myself in terms of strength, but I’m also looking long-term. Is the stuff that I’m going to do going to do damage to me right now, or is it going to evolve me forward? And a lot of the things that I would do as a younger person when I felt as if I was bulletproof and invincible, are not necessarily the most wellness-forward things.”

He continues: “As far as putting 600 lbs. on your back, or really pushing the limits every day and continuing to train without proper recovery, not taking enough time to invest in mobility, not necessarily making the best nutritional decisions, all of those things now need to be at the forefront. I don’t just want to train for today, I want to train for four years from now.

So the perspective has to change. And that once again, that comes with some embarrassing and uncomfortable stuff [admitting] I’m not as strong as I used to be, but it is fun to say, ‘I can still do this.’ I’ve learned to embrace that, and enjoy it. And it hasn’t ruined my love for strength training.”

Cena has added a focus on mobility to his fitness regimen, one that includes yoga and a lot more stretching.

“I do 35 to 40 minutes of uninstructed yoga at the end of every workout,” he says. “Just to keep everything moving and just like strength training with me, I’m there. I don’t take my phone with me. I’m present. I can describe to you the knurling bar where I grip it and the feeling of my body as I’m doing a lift. And I used to hate stretching, but now I love it because it’s a great way to come off of that exertion. I stretch to pain tolerance. So I’m really trying to push my body.”

The actor says committing to his mobility has been both beneficial and fun for him.

“I’ve found it to be extremely therapeutic, and it also helps me move more.” he says. “The body is awesome. In a lot of instances, it’s like an automobile. The body sends up warning lights. And if your oil change light is on or your check brakes light is on, if you’re like, ‘Nah, I’ll fix it later.’ You’re going to get a tow truck on the highway.”

All things considered, Cena also has a shortened version for his fitness/nutrition regimen: “Get enough rest and make good choices. How about that?” he says. “We don’t get enough sleep, and we all eat s—. So just make better choices, and get more rest.”