Wipeout

Wipeout is an American reality game show that airs on ABC. Contestants compete in a series of obstacle courses in what is called the "world's largest obstacle course." The series started on June 24, 2008. It is hosted by John Henson and John Anderson; with Vanessa Lachey acting as a "on-location" host.
There are four rounds of gameplay. In the first round, 24 players play in the "qualifier" obstacle course. The 12 players who complete the course in the fastest time move on to the next round. In the second round, 12 players compete in another obstacle course. The first 6 players to complete the obstacle course move on to the third round. The third round is a third obstacle course. Here, the first 3 players to complete the obstacle course move on to the fourth and last round. The fourth round is the "Wipeout Zone." The 3 players left compete in one more obstacle course to complete the course in the fastest time. The player who completes it in the fastest time wins $50,000.