Woman, 31, Crushed and Paralyzed by Falling Boulder During Beach Visit to Compete in Half Marathon

The urgent care physician and avid runner was crushed by a boulder last April

The last thing Anna Hackenberg remembers about walking along the beach at Torrey Pines State Natural Reserve in San Diego last spring was looking out at the Pacific and feeling a “Zen-like” oneness with the water, sun and sand.

A week later, she woke up in the intensive care unit at Scripps Memorial Hospital La Jolla, paralyzed from the chest down. Doctors said she’d never be able to walk again.

The urgent care physician and avid runner had been crushed by a boulder that had tumbled down the rugged bluff that golden April morning. Anna and two friends on the beach with her didn’t hear the rock break away. In fact, it was only when they turned their heads to talk to talk to her, that they saw Anna lying unconscious on the beach, surrounded by debris and sharp pieces of broken stone.

Courtesy of Anna Hackenberg

Anna, 31, was devastated to learn about her spinal cord injury, but grateful to be alive. And within weeks, she decided that she would participate in the half marathon at San Diego’s Rock ‘n’ Roll Marathon Series in 2018 — this time as a handcyclist.

Courtesy of Anna Hackenberg

Anna Hackenberg on a hike with her dog, Max, in 2016

Courtesy of Anna Hackenberg

“Exercise has always been a big part of my life, so there was never any question that I needed to do it,” Anna, who will be competing as a Toyota-sponsored athlete on June 3rd, tells PEOPLE. “Coming back and getting myself into shape for this was the hardest thing I’ve ever gone through, but also the most rewarding. It’s really made a difference in my life — I know that things could be much worse.”

Now living with her sister, Daphne Hackenberg, 24, Anna has returned to her job at the Sharp Rees-Stealy Urgent Care Center and has spent most of her spare time the past year re-learning how to complete basic tasks such as rolling over in bed, getting into a wheelchair, walking a dog and bathing, along with training on a handcycle donated to her by the Challenged Athletes Foundation.

“Anna’s positive attitude and willingness to try new things and accept help have been the catalyst to her finding a new path in life,” says Kristine Entwistle, the foundation’s associate executive director. “We’re thrilled to support her as she trains for her first competition after her accident — no doubt, the first of many.”

Courtesy of Anna Hackenberg

“When she was injured, I was worried that my sister would have new limits — she could have let her injury define her,” Daphne tells PEOPLE of her sister, “but she continues to surpass them each day with the mindset of an athlete. Anna’s body doesn’t define her — her mind does. She is limitless.”

At the half marathon, more than 30 members of “Team Anna” will be on hand to cheer her toward the finish line, says Anna, who is thankful to them all for “not giving up on me and helping me to make the most of every moment.”

Mike Badami

“I used to throw on my running shoes and head out the door,” she tells PEOPLE, “and now, it’s much more complicated than that. I don’t know where I’d be without everybody’s help. Although it was devastating to learn that I was paralyzed, I’ve had a support system to help me figure out new ways of caring for myself and living my life. Nobody ever let me feel that there was anything to be sad about. For that, I’m truly grateful.”