Physical Well-Being and Functions of Physical Activity

Physical Well-Being

Most school-age children engage in high levels of physical activity, as seen in the opening case study. Physical activity is usually defined as taking place any time the child is not asleep or completely sedentary (Macdonald, Ziviani, & Abbott, 2006). This definition includes lower-level movement activities (e.g., eating, attending school, completing homework, or playing a musical instrument) and higher-level movement activities (e.g., playing on the playground or at a park, as well as participating in organized sports practices or competitions). Research findings show that levels of physical activity increase from infancy, peak in middle childhood, and begin to decrease during middle adolescence (Eaton, McKeen, & Campbell, 2001). This pattern of activity may surprise you because most people assume that 2- or 3-year-olds are the most active. However, when researchers strapped motion recorders on the wrists and ankles of participants aged 6 weeks to 52 years, they found that children between the ages of 7 and 9 were the most active, as seen in Figure (Eaton et al., 2001). This peak of activity occurred later in childhood than others have suggested (Pellegrini & Smith, 1998) and consequently elicits several interesting questions about the function of physical activity. These findings also have direct implications for how we parent and teach these highly active youth as well as how we may diagnose psychopathology, such as attention deficit hyperactivity disorder (ADHD).

Functions of Physical Activity

Researchers have found an inverted U-curved distribution for physical activity, indicating that activity is highest in middle childhood. This curve suggests a sensitive period in development during which motor activity alters brain development. Children’s motor activity peaks at exactly the same time the cerebellum, which is responsible for the control of gross and fine motor movement, is pruning unstimulated synapses and dendrites (Byers, 1998). Researchers have proposed that because most children obtain rudimentary gross motor skills in early childhood, middle childhood is the period in which they seek practice and subsequent refinement of motor skills. In addition, in middle childhood, children may ultimately show mastery of a skill, thus contributing to their sense of self-competency and self-esteem. In other words, being physically active may be one domain in which a child excels (Rose, Larkin, & Berger, 1997).

Physical activity also increases bone mineralization, lowers blood pressure, and may help regulate weight (Heelan et al., 2005). Finally, researchers believe that high levels of physical play behavior, such as rough-and-tumble play, encourage social competency—especially among boys—and support the formation of hierarchical peer groups (Pellegrini & Smith, 1998). Rough-and-tumble play looks like fighting but involves chasing, wrestling, and restraining moves where no real conflict is involved. It is a form of play that assists boys in developing a leadership “pecking order” and, once established, may lead to less aggression and group conflict.

You notice gender differences in the types of activities in which boys and girls engage in the after-school program. In their game of chase, the boys have to be reminded to lower their voices and not play “so rough.” The girls play separately from the boys and play games in which they take turns and accommodate each other’s skill levels.