Rather, the focus is on components of body composition and systems that underlie engagement in physical activity, physical fitness, and chronic disease risk and that in turn influence other aspects of health and academic performance (discussed in Chapter 4). A complete review of the effects of physical activity on all tissues and systems is beyond the scope of this report. Accordingly, this chapter reviews how physical activity may influence developmental processes and other aspects of somatic growth and maturation. Such differences across stages of development highlight the importance of examining the effects of growth and maturation on physical and cognitive health. During the early stages of adolescence, for example, participation in physical activity and corresponding physical fitness begin to decline ( Duncan et al., 2007). To understand the relationship of physical activity and aerobic fitness to health during childhood, it is important first to recognize the developmental changes that occur throughout maturation.
Physical activity has both immediate and long-term health benefits: (a) Physical activity tends to track early physical activity is associated with physical (more.)Įvidence for both direct and indirect health effects of physical activity has been reported ( Hallal et al., 2006), and the need for ongoing participation in physical activity to stimulate and maintain the chronic adaptations that underlie those benefits is well documented. Indeed, growing evidence points to long-term effects of child and adolescent physical activity on adult morbidity and mortality in addition to its more immediate effects ( Hallal et al., 2006) (see Figure 3-1).Ĭonceptual model of how physical activity in childhood and adolescence is beneficial to health. It appears evident, then, that promotion of health-enhancing behaviors must also start early in life. And while the ill effects of chronic disease are manifested mainly in adults, it is increasingly better understood that the development of these conditions starts in childhood and adolescence ( Hallal et al., 2006 Cook et al., 2009 Halfon et al., 2012). Adults engaged in regular physical activity have lower rates of chronic disease (e.g., coronary heart disease, cardiovascular disease, type 2 diabetes, hypertension, osteoporosis, and some cancers) and are less likely to die prematurely ( HHS, 1996, 2008 Bauman, 2004). While more can always be learned, the evidence for the health benefits of physical activity is irrefutable ( HHS, 1996, 2008). 17), physical activity, a behavior, is defined as bodily movement that increases energy expenditure, whereas fitness (more.) As noted in Chapter 1 (see the box titled “Key Terms Used in This Report” on p. (See Box 3-1 for an overview of the relationship between physical activity and physical fitness.) This lack of participation in physical activity has contributed to a greater prevalence of pediatric obesity, a decrease in fitness (e.g., flexibility, muscular strength, cardiorespiratory capacity), and a greater risk for disease ( Boreham and Riddoch, 2001 Eisenmann, 2003 Malina, 2007 Steele et al., 2008). Behaviorally, most children fail to engage in vigorous- or moderate-intensity physical activity for the recommended 60 minutes or more each day, with as many as one-third reporting no physical activity in the preceding 5 days ( CDC, 2012).
Children today weigh more and have a higher body mass index (BMI) than their peers of just a generation earlier ( Ogden et al., 2012). Technological advances of modern society have contributed to a sedentary lifestyle that has changed the phenotype of children from that of 20 years ago. The behaviors and traits of today's children, along with their genetics, are determinants of their growth and development their physical, mental, and psychosocial health and their physical, cognitive, and academic performance. Distinct types of physical activity address unique health concerns and contribute in distinct ways to children's health, suggesting that a varied regimen including aerobic and resistance exercise, structured and unstructured opportunities, and both longer sessions and shorter bouts will likely confer the greatest benefit.