Exercises are often described as being functional. By this, the authors imply that the exercise is specific to a particular sport. The only criteria used in order for the exercise to be functional is that it involve the same muscles as are involved in the execution of the sports skill or that it is similar to the sport skill.
This is far from what the Russians consider to be functional. When an exercise is functional, it is sports-specific and must fulfill very specific criteria. The exercise will then have an immediate and often dramatic effect on skill performance. Exercises that merely involve the same muscles that are used in the sport do not have such an effect.
In general, the more the exercise duplicates what occurs in execution of the sports skill, the greater will be the effect on performance. Merely involving the same muscles does not have a direct effect on performance. This is considered to be a general exercise good for overall conditioning, not for performance.
For example, doing an overhead press strengthens the deltoid muscle, which is used in many sports. In running, however, only the anterior deltoid is used to drive the arm forward. According to the Russians, doing an exercise with the arms going overhead would not be specific to improving arm action in running since it doesn’t strengthen the muscles in the same way as they are used in execution of the running stride. But, it would be considered functional according to many American “specialists”.
Of the criteria used by the Russians, one of the most important is that the exercise must duplicate the same motor (neuromuscular) pathway as seen in the sports skill. In other words, the exercise must duplicate the same movement pattern as used in the skill or in a portion of the skill. In this way, you develop strength in the same way that it is exhibited in the sports skill.
In essence, the closer the strength or explosive exercise is to the actual competitive skill, the greater will be the transfer to the sport. This is the main way you will see greater improvement in your performance. According to the Russians merely getting in better shape or becoming more fit only provides the foundation upon which to do specialized exercises.
For more details and examples of sport specific exercises see Explosive Golf, Explosive Running, Explosive Basketball Training, Explosive Tennis and Women’s Soccer: Using Science to Improve Speed.