Well since I didn't even know there was a sports forum, ill make my debut here. So what do you think is the most physically challenging sport or event? and Explain reasoning. My first vote goes to any fighting sports, boxing, MMA, Muay Thai, K-1, etc. They have to train their entire body for the rigors of fighting, learn to deal with being hit, training for stamina (which is quite different from just running, its a bit more complicated), have strength, speed, and actual fighting knowledge and experience. The only sport where the goal is to hurt or maim your opponent. My second vote: Gymnastics. These guys basically have to torture their bodies from a young age in order to be the best. Totally physically fit, flexibility, difficult muscle memory moves, and the high serious injury probability. Third vote: any long distance event, marathons, bicycle races, triathalons...for obvious reasons. It's hard enough for me to run 4 miles...these guys are running 10 or 20 and cycing across an entire country!