It almost turned out to be a killer workout.

A gym junkie was forced to have his forearm amputated after a botched bicep curl led to him developing a deadly bacterial infection — but now he’s sharing his “amazing” survival story.

Gabriel McKenna-Lieschke, 29, was pumping iron at a gym in Adelaide, Australia when a 110 pound weight caused his bicep to tear “clean off his elbow,” leaving him “screaming in pain.”

After the agonizing accident, the fitness fanatic had surgery to reattach the muscle and believed he was on the road to recovery — but his troubles were just beginning.

“Three days after the surgery, I was sitting around and my arm had swelled up to two or three times the thickness and was bright red,” McKenna-Lieschke told Kennedy News.

The Aussie was rushed back to hospital, where he was diagnosed with necrotising fasciitis. The serious infection — which can develop from something as a simple as a small cut — affects the tissue beneath the skin and surrounding muscles and organs.

Necrotising fasciitis is sometimes described as a “flesh eating” infection, and up to 34% of cases can be fatal, according to the Centers for Disease Control and Prevention. When necrotising fasciitis is complicated by streptococcal toxic shock syndrome, that mortality rate spikes up to 60%, the CDC has reported.

“My dad was calling my friends and family because they’d told him they thought I was going to die,” McKenna-Lieschke stated, revealing he was placed in an induced coma for 10 days.

Doctors were forced to amputate the gym junkie’s right arm, as well as remove dead skin on his chest. The athlete believes he developed necrotising fasciitis during his initial stay in hospital.

“I was asleep for the whole thing. I had no idea what was going on and when I woke up, I didn’t even realize I’d lost my arm for three days,” the youngster explained. “When I looked in the mirror, I was like ‘Oh s–t.’”

He subsequently underwent skin graft surgery to try and reconstruct parts of his upper body.

McKenna-Lieschke candidly told Kennedy News he previously struggled with mental health issues, and was worried that the amputation would send him into a “hole of depression.”

“I’ve had a fairly long history of bad mental health. I got on top of it a year prior to losing my arm,” McKenna-Lieschke explained. “I was really in a good spot and I was really happy. I knew how hard it was to get back from nothing, [and] I’m glad I was in a position where I could tackle it head on because for me it was either ”’t’s time to get on with it or basically kill yourself.’”

Since the incident — which occurred at the end of 2020 — the defiant Australian has “relished” his recovery “as a challenge of self-improvement.”

Incredibly, the fitness fanatic is now training for the 2024 Paralympic Games in Paris.

“I decided to reframe my life so I had a passion again. That’s really important,” McKenna-Lieschke explained. “I don’t know what made me think of it but I said ‘I want to try track cycling’. I’d never been a cyclist before in my life.”

The determined athlete is now training 20 hours per week, in addition to occupational therapy and prosthetics appointments.

Despite the trauma, McKenna-Lieschke has channeled his pain into passion, and is not looking back.

“It’s amazing for me to realize there is a life ahead of me,” he declared.

You can donate to Gabriel McKenna-Lieschke’s GoFundMe here.