When you've jumped more than a football field, farther than Evel Knievel, farther than anyone has ever jumped before – coming up with an encore is difficult.
"I didn't even really know where to start with what could be next and what could be exciting," said Robbie Maddison, who last New Year's Eve in Las Vegas flew 322 feet to break the Guinness World Record for motorcycle jumping.
"The idea of jumping onto a building came, one day when I was rolling down the freeway and I could see a 12-story building. I knew that jumping on that building was definitely possible," Maddison said. "And it became an idea and a dream. And then I started thinking of it more and more and now I'm going to do it."
This year, the 27-year-old Australian will attempt to jump onto a 96-foot replica of the Arc de Triomphe on the Las Vegas Strip, and then freefall 50 feet to a ramp below.
"The jump up the building is one tough thing, but the jump down and the G-forces are incredible at the bottom of the ramp," Maddison said.
To withstand the G-forces, Maddison has trained to strengthen his core muscles.
"The training's been pretty intense. Even with the practice jumps, I've had some close calls, nearly had some crashes and I think it's only from the new strength that it's kept me on the bike," Maddison said. "One time my hands broke the handlebar and my face went into the gas tank. I managed to ride out of it, but the training has definitely giving me some confidence."
With his training complete, Maddison said he is confident he can complete the stunt, but he knows it's not a sure thing.
"I just want to walk away from this thing safe," Maddison said. "Now it's getting to the point where I'm not sleeping very good. Every time I get the thought of doing the jump, my heart skips a beat."
Rhys Millen doesn't consider himself a daredevil, but his resume reflects otherwise. The 36-year-old rally racing and Red Bull Drift Racing champion is also a Hollywood stuntman, having served as lead stunt driver on movies such as "The Dukes of Hazard" and "The Fast and the Furious: Tokyo Drift" – and he likes to backflip trucks in his spare time.
Last New Year's Eve, Millen, a New Zealand native, was hoping to make history of his own by completing the first backflip of an off-road truck. But while on a practice run, his specially designed truck missed the landing area completely and landed directly on its roof.
Millen suffered three broken vertebrae in his neck and two in his back.
"This was really hard for me to be hurt in the fashion that I did," Millen said. "For 16-plus years of racing, I've never sustained an injury, broken bone or anything. You're going to make mistakes when you're pushing those boundaries and we got caught off guard."
After recovering from his injuries, Millen says the hardest part was convincing his family to let him try it again. For him, he said, there was no other choice.
"I was injured, but not enough to break my mind," Millen said. "You can break my body, but you can't break my mind. We're back this year, strong, fit and ready to do it."
Tune in to ESPN on Wednesday, Dec. 31 at 11 p.m. ET/8 p.m. PT to see Rhys Millen and Robbie Maddison jump in "Red Bull: New Year. No Limits in Las Vegas".