“Invictus.” It’s a poem that focuses on the ability to overcome adversity. It’s a rallying cry for those who find themselves in dark and trying situations, who have to dig deep and fight for their lives.

“Invictus” is about being the master of your own fate.

It’s a belief that Justin Goulet lives by.

The words of English poet William Ernest Henley are spread across the 39-year-old’s broad, muscular chest in big, dark letters.

“It’s a poem I hold sacred,” Goulet said while sitting on a bench in his gym at the Center at Colony Mill on Emerald Street in Keene Monday afternoon.

Goulet, who has owned Goulet’s Strength and Fitness since 2014, is its sole employee. He trains clients ranging from doctors and lawyers to police officers and high-schoolers. He fits the bill of a gym fanatic, an ex-competitive powerlifter who stands around 5-foot, 7-inches with 225 pounds of muscle. He’s intimidating in appearance, infectious in personality.

But the stocky, strong and sweet Goulet isn’t working on just his physical game now, but also his mental strength.

Goulet is a recovering heroin addict — clean for the majority of the past six years. He digs deep to overcome his darkness and has rebuilt a life for himself, a life he says wasn’t stolen from him by drugs or addiction.

“I don’t think I lost anything. I gave everything away,” Goulet said.

“I found out when I tried to get sober and follow my own plan, it didn’t work, so I had to trust others. … It’s part of a process.”

Part of that process is helping others be the best they can be by bringing them to their fullest potential.

For the past four years, the same group of Keene High School boys have trained with Goulet four days a week, continually increasing their strength on the bench press and squat rack.

Keegan Murphy, 17, benched 405 pounds on Wednesday, up 20 pounds from his previous lift six weeks ago.

“Justin knows what he’s doing, for sure,” Murphy said.

But Goulet isn’t only teaching the kids about picking up heavy things and putting them back down.

Elizabeth Walsh, 18, another Keene High School student, who will play ice hockey at the University of New England in Maine next year, has torn her ACL twice practicing hockey since meeting Goulet. She started training with him to get stronger.

“He supported me through both injuries and has provided me a place to escape thinking about how upset I was over it. ... He taught me about mental toughness and confidence. ... He wants us to be the best we can be,” Walsh said.

“He’s mentioned how he wishes he could come back to our age and do it all over again. He’s always been open about his story, so we can learn from it.”

Goulet’s story didn’t start when he was using opioids or serving 14 months in federal prison in New York. The White River Junction, Vt., native’s dark days were before that, when he had a career as a Division I strength and conditioning coach for various colleges, including Norwich University in Northfield, Vt.; the University of Albany in New York; and the University of Vermont in Burlington. At that time, he said, he was “empty inside.”

“I was like a zombie from ‘The Walking Dead.’ … I was angry and selfish and wouldn’t listen to anyone else,” Goulet said.

It was a powerlifting injury that caused him to turn to opioids in the first place. After attempting to squat almost 800 pounds during a powerlifting meet in 2003, he slipped and ruptured three discs in his lumbar spine. He was taking 240 milligrams of Oxycontin a day before his doctor cut him off.

“But I don’t blame the doctors,” Goulet said.

“I manipulated them to get what I wanted. I wasn’t a victim.”

Goulet was cut off from his prescription in 2010. Four months later, he had lost his career and home, had turned to heroin and was incarcerated.

“It’s kind of hard to look back and see all of the great things I accomplished and then see all of the (expletive) that went down, but the arrest and the prison time was the best thing that could have ever happened to me,” he said. “It forced me to humble myself and take a look inside.”

Goulet wrote a letter to the editor of The Sentinel in July of last year, addressing the opioid epidemic. In the letter, he explained how he achieved sobriety.

“Embrace a little humility, shut your mouth and admit that your best thinking has gotten you exactly where you are. I know that mine did. The only way that I ever had success was when I shut up, got a sponsor, went to meetings, worked the steps and followed someone else’s plan,” Goulet wrote.

Starting in December 2011, he spent nine months at the Phoenix House in Dublin.

Since then, Goulet has overcome adversity and helps others do the same. He lives in Keene, is engaged to Kasha Bell and has a dog, Frank.

Goulet wouldn’t say it was his fate to own his own gym and train clients — or that he knows his fate at all, for that matter.

What he does know is that he’s the only one responsible for it.

“There is no fate but what we make,” he said.

“And I believe I’ve dedicated myself to a process, and that process has made me the person I am today.”