In Red Rock Canyon, about 30 minutes outside of Las Vegas, Molly Burdick is trying to scale a boulder using nothing more than her hands, feet and some chalk.
No ropes, no harness, just a crash pad to break her fall -- which she does, over and over again. Every time she falls, though, she smiles, shakes out her muscles and starts her ascent back up the rock.
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For most people, this would classify as an intense workout. For Burdick, this is her vacation.
She hasn't always lived the life of an extreme athlete, however. Just a few years ago, she was living like a prisoner in her own house, spending most of her days stuck on the couch.
Burdick was only 25 years old when her life took a sudden turn. She was lying in bed one night when she felt her heart beginning to pound faster and faster. She knew something was wrong as she tried in vain to slow her pulse.
"I saw that putting an ice pack on your chest can be helpful, so I did that," she said. "After an hour, I realized it wasn't going away."
Burdick woke up her toddler son and dropped him off with her parents -- terrified that it could be the final time she ever saw him -- and then rushed to the hospital.
She was having a dangerous arrhythmia. Her heart rate was up to 180 beats per minute.
Doctors tried using medicine to normalize her heart beat. It didn't work.
"They realized that if they didn't take more drastic measures, I was going to go into cardiac arrest. They needed to cardiovert me, which is when they take the electrical shocks to your heart."
That procedure worked, but Burdick was then facing a whole new life -- one as a heart patient.
Mending a wounded heart
Burdick was diagnosed with congenital heart disease.
"It's structural and electrical issues that I was born with,' she said. "However, with me always having been an athlete, I was undiagnosed my entire life."
Alive but in a weakened state, Burdick struggled to regain her strength and control of her life. Once back home, even walking up the stairs caused her heart to race.
"My heart was still always out of control and medication didn't really seem to help," she said. "The idea of even leaving my house was nonexistent. I just remember breaking down one day in bed and crying because I realized this is no life. I'm going to start doing things that make me feel alive."
She began fighting her way back with small steps.
First, the stairs in her house and then walks down the street. Before long she was hiking near her home in Oregon.
After building up her confidence, Burdick decided to push herself to new heights and visited a rock climbing gym.
"I was still super-weak. I didn't even know what I was doing," she said. "It went from just making two moves and falling, to getting stronger and stronger and then climbing outdoors."
'I finally learned to trust my body'
Burdick, now 33, focuses on a specific form of rock climbing called bouldering in which climbers scale smaller rock formations without a rope or harness. Crash pads at the bottom of the rock break their falls.
It's good for building upper body strength and it's been great for her heart.
"It made the healthy parts of my heart stronger and pump a lot better," said Burdick, who lives in Beaverton, Oregon and is a senior product manager at Nike. To get up the boulder you have to slow your heart rate down, stay calm and constantly change your breathing pattern."
Having gone through several procedures, Burdick now has a heart monitor that constantly checks her pulse. She also makes sure to have her heart medication on hand in case of an emergency.
But she's not letting her condition control her life. She's currently training for her next goal -- to be the first American Ninja Warrior with congenital heart disease. "American Ninja Warrior" is a TV reality series in which athletes tackle obstacle courses.
Burdick hopes that by sharing her story, she can help bring some attention to what she calls a "hidden illness."
And she knows her story won't get out if she's stuck on the couch.
"I finally learned to trust my body," she said. "I always tell people that rock climbing saved my life because I wasn't living before this and, for me, that freedom is huge."