How risky is your workout? If the most tough-guy thing you've even done is a Zumba class or pedaling down your city's streets (assuming it's not New York City's streets!), you may be too scared to watch this workout. In it, some pretty crazy guys do push ups, pull ups, and other maneuvers—all from the top of what looks like a very tall crane with no net or harness in sight. The ground seems very, very far away.

Watch it for the stomach-churning suspense (though apparently no one seems to have gotten hurt), and the chance to marvel at the sheer stupidity. Though billed as the "World's Most Dangerous Workout" it may also be the most idiotic. Ever heard of the gym, guys?