From a historical perspective, “the systematization of sports science support for football teams is a relatively recent development which all of the football codes have followed to varying degrees” (Reilly & Araujo 2005: 11).
Coaches elevate their team’s performance through training and instruction. In soccer, the demands placed on the players are grouped as four interdependent components of the game: technique, tactics, fitness and psychology. For raising a team’s high performance potential to its maximum level, and for preventing it from getting weighted down by a weak component, coaching has to focus on improving each of the components. Although performance perfection is never attained in sport, teams can reach their highest peak performance level when all the players are simultaneously
“One of the key principles of sports science is that learning is accelerated when practice activities succeed in replicating the demands of the game” (Daniel 2004: 1). This is termed as the principle of sports specificity. An example is that the ball is rarely stationary in open play, with intensive pace and flight of the ball and timing of the runs; therefore practising crosses using a stationary ball from only 20 yards out does not enhance the players’ skill in successfully executing crosses in a game where on a regulation size field the crosses will originate from further out. Similarly, receiving balls at the edge of the penalty area, and using a leisurely five or six touches to turn and prepare for a shot, does not help a forward to prepare for the demands of his position, because during a competitive match he will not be allowed as much time and space on the ball so close to goal.
The high levels of fitness required by soccer players to meet the physical demands of a game, calls for fitness training that is multifactorial, covering the different aspects of physical performance in soccer.