For a layman health related fitness simply relates to fitness by means of good health but there is more to these words than just this definition. The American College Of Sports Medicine which is considered as the main authority in this field has expressed reservations in this regard stating that in addition to ineffective definitions that had unclear and subjective wordings, the definition includes certain terms which themselves require defining and as a result the term physical fitness has been widely confused and misunderstood. Since this term has been so loosely and inconsistently defined therefore there is no reliable guide for the professionals to measure the physical fitness.For this reason good health and physical fitness has been divided into five essential components. Body composition, flexibility, muscular strength, cardiorespiratory fitness and muscular endurance are the five components through which physical health can be measured and ascertained.
The Center for Diseases Control and Prevention has emphasized that there is a clear difference between health related physical fitness and athletic ability and therefore skilled related fitness has also been divided into six essential components. Reaction time, balance, agility, speed, power and coordination are the six pillars of skill related fitness.