Escape Artist Anthony Martin's Skydive Escape 'Really Didn't Require Much Training'

Escape artist Anthony Martin made headlines this week after he was shackled and locked inside a plywood box, thrown from a plane at 14,500 feet up and freed himself before landing safely. For him, however, it was no big deal.

"As an escape artist I'm always escaping so that part of it really didn't require much training," Martin, 47, said today on " Good Morning America."

"This is actually the second time that I did this," he said. "The first time that I did this was on 'Good Morning America' as well and that was 25 years ago. The purpose that time was just to prove I could do it. I tried to think of the most extreme escape that was ever done and that was it."

Extreme is an understatement. On Tuesday, Martin plummeted through the air at 140 miles per hour above a field in Serena, Ill., outside of Chicago.

Inside the plywood box, Martin's hands were cuffed to a belt around his waist and his right arm chained to the inside of the box, closed shut by a prison door lock.

Outside, the box whipped wildly from side to side. Nearly 37 nail-biting seconds later, Martin somersaulted out of the box and free-falled before parachuting safely down onto the field.

It was that latter portion of his feat, the skydive, not the getting out of a plywood box mid-air while handcuffed, that Martin found the most tricky.

"I don't always skydive so I enlisted the help of my friends at Skydive Chicago, which are the best skydivers in the world, and they trained me and got me prepared to be able to do the escape and, of course, the skydiving portion, without which I wouldn't have been able to be successful," he said.

Martin says he took on his death-defying stunt for a second time, more than two decades later, to promote his book, " Escape or Die: An Escape Artist Unlocks the Secret to Cheating Death."

The renowned escape artist also cleared up a headline-making misconception about his stunt. It was a box that he escaped from, he says, not a coffin.

"To be completely honest with you, I just called it a freight box," Martin said on "GMA." "The media started calling it a coffin. I just never corrected them."