It's the most breathtaking stunt you'll ever see. A woman daredevil does a split on a thin wire 1,000 feet in the air. Then, she does a jaw-dropping move and hangs by her ankles.

So, why would anybody do death-defying stunts like this? INSIDE EDITION spoke via Skype to 25-year-old Hayley Ashburn. She and her friend, Emily Sukiennick, who perform a trick called the "Double Drop" are two of the very few women in the world who participate in the extreme sport known as highlining.  

Ashburn told INSIDE EDITION, "When you overcome a challenge like that it feels amazing, and you just want to do more, longer, bigger, higher."

The video of Ashburn and Sukiennick in Yosemite, California, has  gone viral. The two women set up a 63-foot wire between two steep mountain cliffs to push the limits of their athletic ability.

Ashburn and Sukiennick wear a safety harness in case they fall.

"It's actually not that dangerous because as long as I have my harness on and my leash, even if I fall totally out-of-control on the highline, I'm only going to fall about six or seven feet below the line and I'm just going to dangle there," said Ashburn.

Their friend Jill slipped the first time she tried highlining, but was held up by the harness.

So do we really need to say this—people, don't try this at home!

Ashburn said, "Highlining is dangerous, but we do what we do because it's fun."