With the World Championships of Wrestling just over two months away, wrestlers are jumping at every advantage they can grab hold of to gain the upper hand on their competition.      Members of the U.S. teams joined national coaches Kevin Jackson and Mike Duroe   last week at the U.S. Olympic Training Center in Colorado Springs, Colo. to learn technique and push toward their goal of World gold. After all, champions are made in the training room. These are not mandatory training sessions, but are helping the U.S. athletes prepare for the Worlds in New York City, Sept. 26-29.      "The sooner you start preparing, the better off you are," said Bill Zadick, a member of the freestyle team wrestling at 63 kg. "Wrestling is a thinking man's game. You do your thinking beforehand because you don't have time on the mat."     Other wrestlers taking advantage of the extra training time were Joe Williams, wrestling at 76 kg for the freestyle team, Dominic Black, wrestling at 97 kg for the freestyle team and Toccara Montgomery, wrestling at 68 kg for the women's team.     In addition to the extra mat time, the wrestlers gained valuable personal attention from the coaching staff that they otherwise wouldn't be able to get.      "There aren't as many guys here," Zadick said. "You can work on more specific things."     Williams took advantage of working with the coaching staff to concentrate on some specific techniques.     "I'm working on my par terre position and my movement," Williams said.  "I want to put on a good performance for myself and the fans. I've already got a week's jump on my competition. We got a lot of individual attention. That was really important."      Montgomery used the training sessions to take advantage of practicing with other world-class wrestlers Williams and Ramico Blackmon to prepare for her first international competition. She said the level of coaching and competition at the Olympic Training Center provided a more intense training atmosphere than anywhere else.     "You can only push yourself so much at home," Montgomery said.  "National coaches take it to a different level."     Elite athletes in all three styles take advantage of the training facilities and National Coaching staff at the Olympic Training Center year round. On any given day, a number of world-class wrestlers are in Colorado Springs for personal training opportunities.      However, with the World Championships coming up soon, these special sessions become very important to the success of the U.S. program.