TABLE 4-1 Definitions of Health-Related Fitness Components

Component of Physical Fitness

Definitiona

Relationship to Physical Performance and Healthb

Cardiorespiratory endurance

Ability to sustain moderate intensity, whole-body activity for extended periods

Enhanced physical working capacity

Reduced fatigue

Reduced risk of coronary heart disease

Muscular strength

Maximum force applied with a single muscle contraction

Enhanced functional capacity (lifting, carrying)

Reduced risk of low back pain

Muscular endurance

Ability to perform repeated, high-resistance muscle contractions

Enhanced functional capacity (lifting, carrying)

Reduced risk of low back pain

Flexibility

Range of motion in a joint or series of joints

Enhanced functional capacity (bending, twisting)

Reduced risk of low back pain

Body composition

Fatness; ratio of fat weight to total body weight

Enhanced functional capacity

Reduced risk of chronic disease

aFrom Clarke (1967).

bFrom Pate and Shepard (1989).

nitions present physical fitness as a multidimensional construct. While many earlier operational definitions of physical fitness included numerous motor performance capacities (e.g., coordination, balance, agility), most contemporary definitions view physical fitness as comprised of a small number of core components, each of which is known to determine one’s ability to perform certain types of demanding physical tasks. These core components include cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, and body composition. Collectively, these components have sometimes been referred to as “health-related physical fitness” (U.S. Department of Health and Human Services, 1996). Table 4-1 presents definitions of each of these components of physical fitness; the table also provides a brief indication of the relationship of each component to physical performance and to health.

Measurement of Physical Fitness

Because physical fitness has been conceptualized as a multidimensional construct comprised of several independent factors, comprehensive tests of physical fitness typically include multiple test items. Numerous test batteries have been developed for use in laboratory, quasi-



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