Always wanted to be a Ninja Warrior? Start small and test your strength, stamina and agility with some of Singapore's best indoor and outdoor obstacle courses. With a blend of walls, zip-lines and more, each obstacle course is designed to challenge your upper body strength as much as your cardio, even if it's just in the name of fun. But if you're serious about it, do as Bear Grylls does – "Improvise, adapt, overcome."