Odds are, you probably can't do a backflip.
And you almost certainly can't do backflip on a slackline—a long, two-inch-wide strap of nylon webbing anchored between two points.
"A backflip in general is a scary thing," says Josh Greenwood, a professional slackliner who, on the other hand, can do a backflip. "If you do it wrong, it really hurts you."
Greenwood says that the secret to success is confidence and trust in his abilities, both the result of extensive training. Anything less will result in failure.
"I think if you get to a place where you're totally doubting yourself, people are going to see that—you're not going to succeed," he says. "That totally applies to any kind of work you're going to get into."
"People can do a lot more than they actually think," Greenwood tells us. "It just takes stepping out there."
How about now?