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BOX 3-1 
Physical Activity and Physical Fitness
As noted in Chapter 1 (see the box titled “Key Terms Used in This 
Report” on p. 17), physical activity, a behavior, is defined as bodily move-
ment that increases energy expenditure, whereas fitness is a physiologic 
trait, commonly defined in terms of cardiorespiratory capacity (e.g., 
maximal oxygen consumption), although other components of fitness 
have been defined (IOM, 2012b). Exercise, a subset of physical activity, is 
“planned, structured and repetitive” (Carpersen et al., 1985, p. 128) and 
designed to target a particular outcome, for example, cardiorespiratory 
capacity or another component of fitness. Physical education provides 
opportunities for developmentally appropriate physical activity, usually 
structured to promote motor skill development, fitness, and health. 
The relationship between physical activity and physical fitness is complex 
and bidirectional. Numerous studies have shown a significant relation-
ship between physical activity and cardiorespiratory fitness, which may 
mean that physical activity improves fitness or that physically fit indi-
viduals choose to engage in physical activity more than their less fit 
peers, or both. Experimental studies have shown that exercise training 
improves fitness (Malina et al., 2004), although the response is variable 
and clearly influenced by genetics (Bouchard, 2012), and physical activity 
and fitness are independently related to health and academic perfor-
mance (see the figure below).
Conceptual framework illustrating relationships among physical activity, 
physical fitness, health, and academic performance.
Figure for Box 3-1.eps
Physical Activity
Physical Fitness
Health
Academic 
Performance

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Educating the Student Body: Taking Physical Activity and Physical Education to School
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