Mark Witmer

Mark Witmer (マーク・ウィトマー) is an American gymnast and a co-winner of the American preliminary competition, the American Ninja Challenge.

Witmer was one of the six semifinalists selected for American Ninja Challenge 2. However, he narrowly lost in the head-to-head round to eventual winner Levi Meeuwenberg. Meeuwenberg went on to be the last man standing in the tournament, causing fan outcry against Witmer's elimination.

Perhaps as a result, Witmer was one of the three applicants chosen by the fans to go to Japan through American Ninja Challenge 3. His prize was a spot SASUKE 21 along with Brian Orosco and Luci Romberg. He severly injured the ulnar nerve in his left hand while warming up earlier in the day, and lost most of the feeling in his hand. Without the ability to grip with his fingers, he fell at the Log Grip, an obstacle that requires a strong finger grip. His injury required six months of therapy.

Witmer's injury kept him out of American Ninja Challenge 4. He has not competed in any of the American Ninja Warrior tournaments.