This is something you have to see to believe.
And now that we've seen it, we don't believe it - so you be the judge.
Shawn Johnson, Olympic gold medalist and 2007 winner on Dancing With the Stars, does a back flip over a speeding bobsled.
It's part of an ad campaign for Nestle's called the Nestle Crunch Challenge and it's definitely a challenge.
in gymnastics in 2008 and her athleticism is evident and impressive here - if the video is real.
At least one expert who viewed it told RadarOnline.com: "It's not real. The bobsled is one shot. Shawn doing a back flip is another shot. And they're put together. Can you imagine the liability insurance for something like this if it was real?"
Check out the video.