Good afternoon, Alexey.
I'm not sure that concentration training is included in the training program, even in "top echelon" sports. The concentration of an athlete is a purely individual matter, and each athlete carries out it according to his own "algorithm". It is unlikely that this process is "subject" to the coaching staff, because it is not possible to get into a person's head.
Concentration is most often required in individual sports. For example, in athletics, before jumping, sprinting, throwing a projectile, athletes close their eyes, move their lips, scrolling in their heads the actions that they will now perform. Concentration is very important, for example, in billiards. Before hitting, the athlete concentrates his attention on the aiming ball, but at the same time "keeps in mind" the movement of the cue ball after the balls collide. This aspect is very important in snooker, where it is not so important how the ball is pocketed as where the cue ball ends up. In football, concentration is important before a penalty kick is taken. The kicker and the goalkeeper try to figure out the intention of the opponent in order to win the confrontation.
Concentration is needed so that the athlete can add at an important moment, do not miss the thread of the game.
In professional sports, the result comes first, so athletes, in addition to physical fitness are also working on their psychology. In amateur sports, where the process itself is important, and not the result, the ability to concentrate does not play a big role.
There are many examples in the world of sports when talented athletes, due to psychological problems and inability to concentrate, achieve less than they could would.
Tennis player Fernando Verdasco is a striking example. Since childhood, he has suffered from ADHD - attention deficit hyperactivity disorder. In this regard, he often has drops during one match. One of the most talented and physically developed tennis players of his generation, he could not fully realize himself. At the same time, Verdasco is one of the leaders in the history of tennis in terms of the number of matches played in five sets.
In fact, concentration is important in almost all areas of activity, not just in sports. A trivial example - you are reading a book, images and a plot line are forming in your head. The phone rings and friends invite you to a party. You continue to read the book, but plans for the evening appear in your thoughts, their implementation and the like. At some point, you realize that you've already read three pages, but you don't really understand what it was about. Simply because they have lost concentration and focus on a specific activity.
In high-performance sports, such loss of attention can completely break the athlete's game. Especially when it comes to individual species. For example, if you take tennis, how many situations are there when a player who has played ideally for most of the fight just starts to fall apart and eventually loses the meeting. The reason for this may be some elementary, even insignificant episode that distracted attention, knocked down concentration, which, against the background of physical fatigue, led to a loss of rhythm and defeat. That is why all kinds of coaches, consultants, sports psychologists pay great attention to psychology and the ability to “clear the head” of unnecessary information ... This applies not only to top athletes. Attention is paid to the ability to concentrate even at the level of CYSS. Of course, a lot depends on the quality of the school and its coaches. Serious specialists from childhood work on psychological moments. It is important to lay many nuances in the heads of future champions at a “tender” age.