Athleticism is a term that is used quite often today but to my knowledge has never been defined. Many commentators use it to describe a good skill execution by an athlete, usually something that is typically not seen on that level of play. It often involves a player executing a great catch or a runner eluding his opponents.
Thus the way athleticism is typically used it refers not only to physical development but to motor skills. The latter applies to your ability to execute different movements, techniques and coordination patterns that are involved in a particular sport. In general, a person who has a high level of athleticism is one who is capable of executing all or most of the basic movements that are seen in many sports on a very high level.
Athleticism often includes agility movements such as cutting actions, zigzag running, jumping off balance, throwing on the run, kicking on the run and other similar actions. Being able to execute these athletic movements individually or in combination is related to a great extent on the athlete’s level of strength, flexibility, endurance, coordination and mastery of the basic skills, usually in the early years.
For example, I recall an international volleyball match, which included a team from the Ukraine. They had a tall player who was their best spiker, blocker, setter and receiver. He was as good as, if not better than, the other players who specialized in one skill (as for example a setter) and were good in the other game tasks. He was a classic example of high-level athleticism.
One of the best ways to develop athleticism is to be involved in many sports as a youngster. In so doing, you develop the coordination needed to execute the basic skills and actions that are seen in most sports. For example, once you learn how to run well in one sport, it will carry over to the other sports. Thus, the more varied your background, the greater will be your ability to execute just about any skill and thus play the sport successfully.
This is one of the reasons why I strongly advise against specializing in only one sport at an early age. By playing only one sport, after you learn the rudiments of the basic skills for that sport, you only learn more strategy. You do not develop the ability to execute new and different movements or other skills that are needed in not only the main sport, but in other sports. Sometimes the development that the athlete receives enables him to pick up and learn new skills that may also be needed when playing on the highest levels.
As sports and sport technique continually evolve, you must prepare the youngster with the ability to master new skills that may be required on the highest levels of play as an adult. This is one reason why so many youngsters who specialize and excel when they are very young often do not do as well after the teenage years.
Athleticism is closely related to physical abilities. The greater the development of your strength, flexibility, speed, quickness, etc., the more able and the better equipped you are to execute the different skills. In essence, your skills can be improved not only by improving your technique, but by developing the physical abilities as they relate specifically to the skill in question.
This means that your physical abilities must be coupled together with technique. In this way, your technique and physical abilities will increase at the same time allowing you to display the best execution and overall game play. Coupling of the physical abilities with technique is seen when doing specialized strength exercises, also known as dynamic correspondence exercises.
For more information see Build a Better Athlete. This is the only book that shows execution of the basic skills with sequence pictures taken from live digital film. In addition, it explains the need for the physical qualities and how they can be developed. For related information in specific sports see Explosive Running, Explosive Golf, Explosive Tennis and Secrets of Russian Sports Fitness and Training.