Magician David Blaine has been buried alive for seven days, frozen for 61 hours, perched 90 feet up on a pole for 35 hours, and suspended for 44 days.
Now, he has been submerged in a human aquarium and plans to stay there for a week.
"My system is completely empty," he said before being submerged. "So that way in the sphere I don't have to use the bathroom. I have a catheter in case I have to do No. 1, but I don't intend on doing anything else."
To prepare for his weeklong stay in 2,000 gallons of 96-degree saltwater, Blaine underwent grueling training with the Navy SEALs and oxygen deprivation while diving with stingrays.
"What was amazing about the Navy SEALs -- a lot of their training, although it is physical, is more about the mental and spiritual part," said Blaine, 33. "They talk about overriding the pain in your body by finding something to take you away from it."
If he survives his seven-day endurance test, Blaine will handcuff himself to 150 pounds of chain and then remove his breathing apparatus. He hopes to break the world record of almost nine minutes without breathing. The stunt will be broadcast on ABC on May 8.
"I'll have to escape from all these chains, and if not I will drown and the world will see something pretty insane," he said.
Blaine said he had lost 50 pounds while practicing holding his breath.
"I would wake up and hold my breath for 48 minutes out of the course of every hour," he said. "I'd breathe for a minute, hold my breath for five minutes immediately after, and then right after that, breathe a minute, hold for six minutes and keep going for all the way up to an hour. In that process, your CO2 levels become so high, your body has to work like a marathon runner to get rid of it."
The final escape will be the difficult part, and Blaine has been relaxing in his fish tank, which sits outside Lincoln Center in Manhattan, N.Y., where pedestrians can view him. Blaine, who is 6-foot-1, appears about 33 percent larger because of the way the spherical tank refracts the light.
"So far, not bad," Blaine said, about 20 hours into the stunt. "The only difficulty I have been having is that my hands are already mangled and my feet are pretty bad. It feels like pins and needles, and the flesh is starting to get little perforations. By the end of the week, your skin becomes kind of like paper. It becomes really fragile and delicate."
To soothe his hands, Blaine has put on some gloves with petroleum jellylike cream inside them.
Blaine, who is subsisting on a tube-fed liquid diet of Gatorade, Pedialyte and water, said he also had difficulty sleeping because of the water pressure, which makes his head throb.
Despite all the risks and hardships, Blaine said he was enjoying his stay.
"This one is the most fun of all of them," he said. "I almost feel guilty doing it. It feels so good to be in here."