David Blaine's next stunt to be conducted on Winfrey's show

CHICAGO -- He spent 44 days suspended from a glass box by the River Thames in London. He was buried alive for a week in a see-through coffin in New York.

Magician David Blaine's latest feat of endurance likely will last less than 17 minutes, but he's planning to do it in front of talk show queen Oprah Winfrey -- and her audience of millions.

Today, Blaine will try to break the world record for breath-holding during a live broadcast of "The Oprah Winfrey Show," less than two years after going into convulsions during a similar attempt.

The time he has to beat is 16 minutes and 32 seconds, a record set Feb. 10 by Switzerland's Peter Colat, according to Guinness World Records.

Even though Blaine has sometimes attracted thousands of spectators to what he likes to think of as his "performance pieces," he said Tuesday that it will be a challenge to break a record requiring him to remain still and calm amid the hubbub of a live studio audience.

Still, he said, the crowds have always contributed to his success.

"When you commit to it and there's people watching, you kind of have to stick to it. You can't back out, you can't fade away and you can't cheat," he said.

"If I was doing it alone, I'd probably be off sneaking out of the box in London or grabbing some food," he said with a laugh, speaking in a conference room in a Harpo Productions building a couple blocks from Winfrey's television studio.

Blaine, 35, will be attempting his latest stunt in a water-filled sphere, dubbed a "human aquarium" by his team, that's 8 feet in diameter. He'll try to remain perfectly still, relax and lower his heart rate to minimize oxygen consumption.

But before he enters the sphere, he plans to spend about 23 minutes breathing pure oxygen through a mask to saturate his blood with oxygen and flush out carbon dioxide. Up to 30 minutes of so-called "oxygen hyperventilation" is allowed under Guinness guidelines, according to company spokeswoman Laura Plunkett.

In May 2006 -- as a finale to a week spent in the aquarium with an oxygen mask at New York's Lincoln Center -- Blaine tried to set a new breath-holding record. Without breathing pure oxygen beforehand, he tried to break the existing record of 8 minutes, 58 seconds.

But he had to be rescued shortly after 7 minutes when he was unconscious and having convulsions.

When he decided to try a version of the stunt again, he began training in pools and the ocean with experts in free diving.

Through nutrition, light cardio workouts and cutting out alcohol and caffeine Blaine said he's been able to lower his resting heart rate to about 38 beats per minute, similar to that seen in highly conditioned endurance-trained athletes.

Demonstrating his focus on Wednesday's challenge, Blaine showed off the screensaver on his iPhone: It's a chart listing how long various types of mammals can hold their breath, on average.

For humans it's 1 minute. Platypuses can hold their breath for 10 minutes, hippos for 15 minutes, beavers 20 minutes, and bottlenose whales 120 minutes.

"I think my real competition is the beaver," Blaine said, smiling, "not the bottlenose whales."