Skydiving is one of the world's biggest thrills, an adrenaline rush like no other. It may be still a niche activity, but indoor skydiving is already quite popular in Europe and the U.S. And it's fast gaining legitimacy as a sport in Asia too. A big credit for that goes to a group of Singaporean skydivers, between 13 to 20 years old, who recently won four gold medals at the 4th World Cup of Indoor Skydiving. CGTN's Miro Lu caught up with some of them at their home tunnel.