David Gruner was a 33-year old craftsman who competed on the inaugural American Ninja Warrior tournament. According to Gruner, he does not use conventional fitness methods to stay in shape, but rather uses unconventional sports such as BMX biking, frisbee golf, and even hacky-sack to train.
In qualifying, his run was digested, but it was shown that he cleared the course in 44.4 seconds, placing 14th overall and moving on to the semis.
In the semis, he had a chance to knock Ruselis Perry out of the top 15. Unfortunately, that did not happen, as on the Pipe Slider, due to the poor friction of the track, the bar slid too far down the first jolt and twisted off the track, sending him into the water. He placed 29th overall, and did not move on.