Listen to the Audio Article from NPR TRX: Randy Hetrick
In 1997, Navy SEAL Randy Hetrick was deployed in Southeast Asia, where he was stationed in a remote warehouse for weeks with no way to exercise. So he grabbed an old jujitsu belt, threw it over a door, and started doing pull-ups. Today, TRX exercise straps dangle from the ceiling in gyms across the country and are standard workout gear for professional athletes.