NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Committee on Physical Activity and Physical Education in the School Environment; Food and Nutrition Board; Institute of Medicine; Kohl HW III, Cook HD, editors. Educating the Student Body: Taking Physical Activity and Physical Education to School. Washington (DC): National Academies Press (US); 2013 Oct 30.

Cover of Educating the Student Body

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

Show details

2Status and Trends of Physical Activity Behaviors and Related School Policies

Key Messages

  • Few children in the United States, probably no more than half, meet the currently recommended standard of at least 60 minutes of vigorous- or moderate-intensity physical activity daily.

    The proportion meeting the standard declines with age, with more elementary school children than middle and high school students achieving the goal. Boys are more likely than girls to meet the recommendation.

    During the past 30-40 years, probably even longer, the volume and intensity of daily physical activity among youth have gradually declined.

  • Given the large proportion of total waking hours spent at school and in school-related activities, remarkably little is known about students' physical activity behaviors during school hours and during school-related after-school activities. Despite some excellent research and a few good public health surveillance systems, current monitoring of overall and school-related physical activity behaviors among youth and school-related policies and practices that enable or impede those behaviors is inadequate.
  • An adequate description of the current status of and monitoring of changes in students' school-related physical activity behaviors currently is not possible. Public health and education surveillance and research need to be enhanced so that the impact of efforts to increase students' physical activity can be monitored.
  • Policies are and will be important in creating an atmosphere in schools that enables, facilitates, and encourages children to be more physically active. Less clear are the factors that create an effective policy. An understanding is needed of what facilitators (e.g., funding, promotions, awards) and enforcers (e.g., less funding, job security) lead to policies that are fully implemented.

As discussed in further detail throughout this chapter, few children in the United States, probably no more than half, meet the currently recommended standard of at least 60 minutes of vigorous- or moderate-intensity physical activity daily (CDC, 2012b). In addition, the proportion meeting the standard declines with age, with more elementary school children than middle and high school students achieving the goal. Boys are more likely than girls to meet the recommendation. Finally, it can be said with reasonable certainty that during the past 30-40 years, probably even longer, the volume and intensity of daily physical activity among youth have gradually declined.

It is also known that because children and adolescents spend so many hours at school, school-related physical activity must be a large contributor to overall physical activity among youth. Not known, however, is exactly how large the overall contribution is or the contribution of each segment of the school day—transportation to and from school, physical education, recess, classroom time, and before- and after-school activities. It is known that over the past 40 years the proportion of children walking and biking to school has declined substantially; otherwise, there are at best rough estimates of the current physical activity behaviors, recent changes, or long-term trends associated with each of these segments of the school day.

Guidelines, recommendations, and policies from all levels of government (federal, state, district, local) and from various organizations (e.g., National Association for Sport and Physical Education, American College of Sports Medicine) are known to influence youth's school-related physical activity. Understood as well is that the strength of that influence is, in turn, affected by incentives and enforcements associated with those guidelines, recommendations, and policies (see Figure 1-3 in Chapter 1). What remains unclear is which guidelines, recommendations, policies, incentives, and enforcements are most influential in today's social milieu.

What should also be apparent is that, despite some excellent research and a few good public health surveillance systems, current monitoring of overall and school-related physical activity behaviors and school-related policies and practices that enable or impede those behaviors is inadequate. These deficiencies have arisen for several reasons. First, physical activity has only recently been acknowledged as a vital public health issue, so monitoring of the volume of physical activity at the population level is a recent objective with still insufficient priority. The Physical Activity and Health Branch of the Centers for Disease Control and Prevention (CDC) was not established until 1996, and the first formal federal-level physical activity guidelines were not published until 2008 (HHS, 2008). Second, physical activity is a notoriously difficult behavior to measure. Third, understanding of the types and amounts of physical activity relevant to health and health outcomes is still growing. The types and amounts of physical activity recommended for children and adolescents have changed several times in the past 20 years, frustrating efforts to monitor trends. Fourth, information is scarce on prevalence and trends for policies that may enable (or inhibit) physical activity. Examples include school- and district-level policies on recess and training for physical education teachers, as well as community or neighborhood policies on active transport to and from school. Monitoring of policies and practices is improving but needs expansion and maturation. Finally, schools and school districts vary greatly in size, resources, environmental setting, urbanization, population characteristics, traditions, and policies. Summary assessments and measures may capture the national gestalt but omit important differences among subgroups.

Physical Activity Versus Exercise

Physical activity is defined as all human movement; it is done at some rate of energy expenditure in all settings and for many different purposes. Exercise is a subcomponent of physical activity that is done for the purpose of increasing physical fitness. Intensity (i.e., rate of energy expenditure) is an important descriptor of physical activity because different intensities have different physiologic effects. Both physical activity and exercise encompass the full range of energy expenditure.

The purpose of this chapter is to describe the evidence supporting these general statements about the status and trends of the physical activity behaviors of school-age children and adolescents, as well as the school-related policies and practices that help determine those behaviors. Description of the status and trends of physical activity behaviors of youth requires, along the way, some discussion about the behaviors themselves, how they are measured, and how the current recommendations came into being.

PHYSICAL ACTIVITY

Unless they take a nap or lie down to rest, all people are physically active from the time they get up in the morning until they go to bed at night. Physical activity is a necessary part of everything people do at home, work, or school; while going from place to place; and during leisure time. Few people in the United States, whether adults or children, expend a great deal of energy during physical activity, but they are always expending some. In the still-emerging field of physical activity and public health, physical activity is commonly defined as “any bodily movement produced by skeletal muscles that results in energy expenditure” (Caspersen et al., 1985, p. 126). Despite this straightforward definition, physical activity is a complex behavior with a wide variety of types and intensities. Types of physical activity may be categorized, for example, by type of movement (e.g., walking, skipping), by sport (e.g., soccer, badminton), by life context (e.g., at school, at home, during transportation), or by predominant physiologic effect (e.g., cardiorespiratory conditioning, muscle strengthening). Regardless of the categorization scheme, physical activity operates through multiple physiologic pathways to influence many health outcomes. Although physical activity can be categorized and discussed in many ways, aerobic activities are the most common and have the broadest physiologic and health effects. Aerobic activities are commonly categorized as being of sedentary, light, moderate, or vigorous intensity based on the rate of energy expenditure (see Box 2-1).

Box Icon

BOX 2-1

Categories of Intensity of Physical Activity. Aerobic activities are common and important. Such activities include walking, dancing, and playing soccer or basketball, all of which involve large muscle groups in rhythmic repetitive movement. Aerobic activities (more...)

STATUS OF PHYSICAL ACTIVITY BEHAVIORS AMONG YOUTH

This section reviews what is known about the status of physical activity behaviors among youth, first for vigorous- or moderate-intensity activity, next for sedentary or light-intensity activity, and finally for vigorous- or moderate-intensity activity during the school day.

Vigorous- or Moderate-Intensity Physical Activity

Vigorous- or moderate-intensity physical activity is important for normal growth and development (see Chapter 3), including maintenance of healthy body composition, and reduces the likelihood of acquiring risk factors for the development of chronic diseases later in life. The currently recommended dose of physical activity for children and adolescents is at least 60 minutes of vigorous- or moderate-intensity physical activity per day, with vigorous physical activity on at least 3 of those days (Strong et al., 2005; PAGAC, 2008).

In 2005 a panel was convened by the CDC specifically to consider the physical activity needs of children and adolescents (6–18 years of age). The panel reported beneficial effects of regular physical activity on muscular health, cardiovascular health, adiposity, blood pressure, blood lipid levels, self-concept, anxiety, depressive symptoms, and academic performance. The optimal dose was more difficult to determine for at least two reasons (see also Box 2-2). First, different health outcomes accrue from different doses. Second, research demonstrates a positive dose response rather an ideal dose. The panel concluded, however, that “school-aged youth should participate every day in 60 minutes or more of moderate to vigorous physical activity that is enjoyable and developmentally appropriate” (Strong et al., 2005, p. 736). In 2008 the Physical Activity Guidelines Advisory Committee also reviewed the scientific evidence relating to physical activity and the health of children and adolescents (PAGAC, 2008). That committee confirmed the benefits reported by the previous panel. The committee also agreed that it is difficult to select a minimal or optimal dose of physical activity for youth but reaffirmed the recommendation for 60 minutes or more per day of vigorous or moderate physical activity. The committee further commented that weekly activity should include some vigorous activity on at least 3 days and some activities to strengthen muscles and bones.

Box Icon

BOX 2-2

Dose of Physical Activity. The dose of physical activity, sometimes referred to as volume or amount, is a function of the type, frequency, duration, and intensity of the activity. Until recently, benefits appeared to derive almost exclusively from vigorous- (more...)

Available information indicates that relatively few youth achieve a daily dose of at least 60 minutes of vigorous- or moderate-intensity physical activity. Information on the proportion of youth who are vigorously active on 3 or more days per week is not available. However, about 10 percent of middle and high school students responding to the Youth Risk Behavior Survey (YRBS), conducted by the CDC and state health departments, self-reported that on no days in the previous week did they spend at least 60 minutes doing vigorous- or moderate-intensity physical activity, about 50 percent reported doing so on at least 5 days, and about 30 percent reported meeting the recommended 7 days (CDC, 2012b) (see Figure 2-1). In a different ongoing national survey of 8th-, 10th-, and 12th-grade students—Monitoring the Future—fewer than half of students reported doing 60 or more minutes of vigorous activity every or almost every day (Delva et al., 2006).

FIGURE 2-1. Percentage of middle and high school students reporting they engaged in no days, 5 days, or 7 days per week of 60+ minutes of vigorous- or moderate-intensity physical activity.

FIGURE 2-1

Percentage of middle and high school students reporting they engaged in no days, 5 days, or 7 days per week of 60+ minutes of vigorous- or moderate-intensity physical activity. NOTE: The middle school estimate is the mean of 15 statewide surveys; the (more...)

Results from surveys measuring physical activity with accelerometers and including younger children similarly suggest that few children, especially older ones, meet the currently recommended volume of vigorous- or moderate-intensity physical activity. A study of accelerometer-measured physical activity among students in central Massachusetts found that almost all students in grades 1-6, but fewer than one-third of high school students, performed at least 60 minutes of vigorous- or moderate-intensity physical activity at least 5 days per week (Pate et al., 2002) (see Figure 2-2); the proportion of students meeting the 7-day recommendation would, of course, be lower. Also worth noting is that for high school students in this study, the accelerometer-estimated prevalence is about half the self-reported estimated prevalence for the same dose among students responding to the YRBS (see Figure 2-1). (See Box 2-3 on measuring physical activity.)

FIGURE 2-2. Percentage of students performing accelerometer-measured vigorous- or moderate-intensity physical activity for at least 60 minutes on at least 5 days per week, by grade.

FIGURE 2-2

Percentage of students performing accelerometer-measured vigorous- or moderate-intensity physical activity for at least 60 minutes on at least 5 days per week, by grade. SOURCE: Adapted from Pate et al., 2002.

Results of other surveys confirm the decline in vigorous- or moderate-intensity physical activity with age (Nader et al., 2008; Troiano et al., 2008). Figure 2-3 displays the mean number of minutes of vigorous- or moderate-intensity physical activity per day rather than the proportion who do or do not achieve a set number of minutes, as presented in Figures 2-1 and 2-2. These three figures illustrate some of the difficulties entailed in comparing studies that used different measurement methods (i.e., self-report versus accelerometer-measured) and different types of data summary (i.e., proportion meeting a specific standard versus average of the whole group).

FIGURE 2-3. Average minutes/day of accelerometer-measured vigorous- or moderate-intensity physical activity by years of age and source.

FIGURE 2-3

Average minutes/day of accelerometer-measured vigorous- or moderate-intensity physical activity by years of age and source. NOTE: NHANES = National Health and Nutrition Examination Survey. SOURCES: Nader et al., 2008; Troiano et al., 2008.

In addition to the low proportion of children and adolescents meeting currently recommended physical activity levels and the decline in vigorous-or moderate-intensity physical activity with age, data from the above and other surveys indicate, almost without exception, that girls are less active than boys (see Figure 2-4). Patterns of activity by race/ethnicity are less clear. Large surveys (e.g., YRBS, Monitoring the Future) using self-reported information usually find that whites report more vigorous- or moderate-intensity physical activity than other racial/ethnic groups (Simons-Morton et al., 1997; Delva et al., 2006; CDC, 2012a). In the National Health and Nutrition Examination Survey (NHANES), however, in which physical activity is assessed using accelerometers, non-Hispanic blacks are the group with the most vigorous- or moderate-intensity physical activity (Troiano et al., 2008; Gortmaker et al., 2012). In a study of 6th-grade girls from six states, also using accelerometers to assess physical activity, white girls had the highest average number of minutes of vigorous- or moderate-intensity physical activity, while African American girls had the highest prevalence of meeting physical activity recommendations (Pate et al., 2006b). An analysis of youth aged 12-19 who performed treadmill tests as part of the NHANES found that about one-third of subjects failed to meet standards for cardiovascular fitness, but there were no significant differences in the prevalence of acceptable cardiovascular fitness among non-Hispanic white, non-Hispanic black, and Mexican American subjects (Pate et al., 2006a). Physical fitness and physical activity are different but directly related concepts. Finding no differences in cardiovascular fitness among groups suggests that there also are no differences in overall amounts of vigorous- and moderate-intensity physical activity.

FIGURE 2-4. Percentage of youth reporting at least 60 minutes of vigorous- or moderate-intensity physical activity daily by sex: self-reported estimates from the Youth Risk Behavior Survey (YRBS) (2011) and accelerometer estimates from the National Health and Nutrition Examination Survey (NHANES) (2003–2004).

FIGURE 2-4

Percentage of youth reporting at least 60 minutes of vigorous- or moderate-intensity physical activity daily by sex: self-reported estimates from the Youth Risk Behavior Survey (YRBS) (2011) and accelerometer estimates from the National Health and Nutrition (more...)

Fewer data are available with which to assess the influence of socio-economic status on physical activity behaviors, and these data, too, provide no clear picture. Proxy information from the NHANES for children aged 6-11 indicate that a higher proportion from low-income than from high-income families meet current recommendations for vigorous- or moderate-intensity physical activity (Fakhouri et al., 2013). Self-reported information from children 9-13 years of age and their parents shows a slightly lower percentage (74 percent) of children from low-income (≤$25,000/year) than from high-income (>$50,000/year) families (78 percent) engaging in free-time vigorous- or moderate-intensity physical activity (CDC, 2003). This same survey did find that substantially fewer children from low-income (24 percent) than high-income (49 percent) families participate in organized physical activities because of transportation problems, expense, and lack of opportunities.

Despite limited information about differences, if any, in physical activity behaviors among racial/ethnic or socioeconomic groups, information about the variability of funding among school districts across the United States suggests that not all students have equal opportunities for participating in physical activity during the school day. Schools are funded by local and state governments, as well as the federal government. During the past 50 years, local and state governments have each provided about 45 percent of school funding, with the federal government providing about 10 percent. Considerable variation exists, however, among states and school districts in per-pupil expenditures for elementary and secondary education and in the sources of the funds.

In the 2008–2009 school year, per-pupil expenditures ranged from $6,612 in Utah to $19,698 in the District of Columbia (see Figure 2-5). The source of those funds also varied markedly among states. The federal portion of annual expenditures ranged from 4 percent in New Jersey to 16 percent in South Dakota (New America Foundation, 2012). The proportion of state funding, mainly from income and sales taxes, ranged from 86 percent in Vermont to 28 percent in Illinois; local funding, mainly from property taxes, ranged from 60 percent in Nevada to 3 percent in Hawaii.

FIGURE 2-5. Per pupil expenditures for public elementary and secondary education in the United States, 2008–2009.

FIGURE 2-5

Per pupil expenditures for public elementary and secondary education in the United States, 2008–2009. 1U.S. estimates are for the 50 states and the District of Columbia. NOTE: The prekindergarten student membership was imputed for some states, (more...)

Substantial within-state variation in per-pupil expenditures also exists. A general assumption is that the quality of education is directly linked to the quantity of funding. However, different systems have different levels of efficiency, and living costs and workforce salaries vary among and within states. In addition, educating children from low-income homes, those with disabilities, or those for whom English is a second language costs more. Various methods have been proposed for comparing funding levels among different school districts, including simple dollar-to-dollar comparisons; cost-of-living adjustments; and “level-of-effort” adjustments, such as proportion of total taxable state and local resources or state per capita gross domestic product (Epstein, 2011).

While the best way to measure and resolve differences in educational opportunities among and within states is uncertain, it is clear that substantial differences exist. Children and adolescents from low-income families are more likely to live in low-income school districts and have fewer resources for public education. It appears likely that fewer resources for education systems result in fewer opportunities for school-related physical activity. As noted above, however, information about the differences in physical activity behaviors among different racial/ethnic and socioeconomic groups is sparse and inconsistent.

Sedentary or Light-Intensity Physical Activity

Recent evidence indicates that light-intensity physical activity, although not likely a substitute for vigorous- or moderate-intensity physical activity, is beneficial to health. Research has focused on the detrimental health impact of sedentary-intensity physical activity, usually sitting or watching television, but the evidence can just as well be described as showing benefits from light-intensity physical activity (see Box 2-4). The relative merits of different levels and combinations of physical activity intensities are being investigated and discussed, but the lower end of the spectrum of rate of energy expenditure is now receiving attention previously reserved for the higher end.

Box Icon

BOX 2-4

Recognizing the Value of Light-Intensity Physical Activity. Thirty to 40 years ago, only vigorous physical activity was thought to provide reductions in disease risk. By the early 1990s, however, it was clear that moderate-intensity physical activities (more...)

An important aspect of sedentary-intensity physical activity is the large portion of waking hours it fills. Assuming about 15 hours per day of wakefulness, sedentary and light-intensity physical activities fill 80 percent of waking hours for youth who spend 3 hours doing vigorous- or moderate-intensity physical activities (see Figure 2-6). For youth just meeting the 60-minute daily recommendation for the latter activities, the former would fill 93 percent of the day. For the majority of youth not meeting the current recommendation for vigorous- or moderate-intensity physical activity, nearly the whole day comprises sedentary and light-intensity physical activities (Treuth et al., 2012).

FIGURE 2-6. Approximate number of hours spent during the day at different levels of energy expenditure.

FIGURE 2-6

Approximate number of hours spent during the day at different levels of energy expenditure. SOURCE: Treuth et al., 2012.

Various suggestions have been made about what aspects of youth's sedentary physical activity should be avoided and monitored, including limiting television viewing to less than 2 hours per day, limiting television viewing to less than 3 hours per day, limiting computer use to less than 3 hours per day, and limiting total media time to less than 2 hours per day (see, e.g., the Healthy People 2020 objectives [HealthyPeople.gov, 2012]).

Not surprisingly, surveys and studies of sedentary behavior among children and adolescents have used various methods of data collection (e.g., self-report, accelerometer, proxy), have assessed different aspects of sedentary-intensity physical activity (e.g., total sedentary time, watching television for more than 2 or 3 hours), and have reported the data in different formats (e.g., percentage meeting a specified requirement, mean minutes of sedentary physical activity). Taken together, the results of these surveys and studies indicate that children and adolescents spend a great deal of time in activities requiring very low energy expenditure. The results also indicate that girls are more likely than boys and older adolescents are more likely than children to engage in these low-energy activities, although the differences are generally smaller than for vigorous- or moderate-intensity physical activity.

Data from the YRBS and the NHANES are the most frequently cited. Based on accelerometer-assessed physical activity, youth aged 6-19 engage in sedentary physical activity 6-8 hours per day (Matthews et al., 2008) (see Figure 2-7). Figure 2-7 also provides estimates of the average time per day spent using different types of media (TVB, 2012). Reports from the YRBS suggest that about one-third of both middle and high school students report watching television for at least 3 hours per day. In response to a different question, those in this age group (not necessarily the same students) report using a computer for at least 3 hours per day (CDC, 2012b). Other reports (Anderson et al., 2008; Sisson et al., 2009; Wright et al., 2009) and a review (Pate et al., 2011) are available. Data from two reasonably comparable studies demonstrate the reduction in vigorous- or moderate-intensity physical activity and the rise in sedentary and light-intensity activity as girls grow from age 5 to 8 to 12 (Janz et al., 2005; Pate et al., 2006b) (see Figure 2-8).

FIGURE 2-7. Hours per day spent in sedentary activity by age group, ages 6-19, and hours per day using different media sources, ages 13-17.

FIGURE 2-7

Hours per day spent in sedentary activity by age group, ages 6-19, and hours per day using different media sources, ages 13-17. NOTE: NHANES = National Health and Nutrition Examination Survey. SOURCES: Matthews et al., 2008; TVB, 2012.

FIGURE 2-8. Percentage of waking hours spent in sedentary, light, moderate, and vigorous physical activity by girls aged 5 and 8 (all from Iowa) and aged 12 (from Arizona; California; Louisiana; Maryland; Minnesota; South Carolina; and Washington, DC).

FIGURE 2-8

Percentage of waking hours spent in sedentary, light, moderate, and vigorous physical activity by girls aged 5 and 8 (all from Iowa) and aged 12 (from Arizona; California; Louisiana; Maryland; Minnesota; South Carolina; and Washington, DC). SOURCES: Janz (more...)

Vigorous- or Moderate-Intensity Physical Activity During the School Day

In the United States, elementary and secondary school students spend 180 days every year at school. On those days, about 6.5 hours, or about 40 percent of their waking hours, make up the official school day. Including time spent going to and from school and in school-related after-school activities, students spend half or more of the available hours of every school day at school or going to and from school. Given the large proportion of total waking hours spent at school and in school-related activities, remarkably little is known about students' physical activity behaviors during school hours and during school-related after-school activities.

A recent analysis of the potential impact of select school-based policies indicates that the current dose of vigorous- or moderate-intensity physical activity at school could be substantially increased (Bassett et al., 2013; see Figure 2-9; see also Chapter 7):

FIGURE 2-9. Minutes per day of vigorous- or moderate-intensity physical activity gained by implementing school-based policies.

FIGURE 2-9

Minutes per day of vigorous- or moderate-intensity physical activity gained by implementing school-based policies. NOTE: PE = physical education. SOURCE: Bassett et al., 2013.

  • Compared with no physical education, a usual physical education class adds about 23 minutes of vigorous- or moderate-intensity physical activity to a student's day.
  • Using a standardized high-quality physical education program can add another 5 minutes. High-quality or enhanced physical education programs strive, among other things, to devote at least 50 percent of physical education time to vigorous- or moderate-intensity physical activity.
  • Programs that enable and encourage more vigorous- or moderate-intensity physical activity during recess by providing age-appropriate equipment, blacktop games, and/or adult encouragement and supervision can add another 5 minutes.
  • Inserting vigorous- or moderate-intensity physical activity into the classroom by incorporating physical activity into the lesson or by providing specific activity breaks can add about 19 minutes per day above the usual time.
  • Walking or biking to school compared with being driven can add about 16 minutes of vigorous- or moderate-intensity physical activity to the school day.
  • After-school activity programs can add another 10 minutes of vigorous- or moderate-intensity physical activity per school day.

Despite evidence that policies and programs can increase vigorous-or moderate-intensity physical activity among children and adolescents on school days, only rough estimates are available, at best, of students' baseline physical activity behaviors at school and during school-related activities. Therefore, only rough estimates can be made of the volume of vigorous- or moderate-intensity physical activity that is being and could be achieved.

Physical Education

Children in elementary and middle school spend about 10-40 percent of their time in physical education classes engaged in vigorous- or moderate-intensity physical activity (Simons-Morton et al., 1993, 1994; McKenzie et al., 1996; Sallis et al., 1997; Belsky et al., 2003; McKenzie et al., 2006). On average they have two physical education class periods per week, each for about 30 minutes (Belsky et al., 2003). Assuming that 35 percent of physical education time is spent in vigorous- or moderate-intensity physical activity, children spend an average of 4 minutes per school day doing vigorous- or moderate-intensity physical activity in physical education classes (see Table 2-1). If elementary school students had 30 minutes of physical education daily (150 minutes per week) and middle school students had 45 minutes of physical education daily (225 minutes per week), the estimated number of minutes per day spent doing vigorous-or moderate-intensity physical activity during physical education would increase to 11 minutes and 16 minutes, respectively. If the proportion of time in vigorous- or moderate-intensity physical activity during physical education were increased to 50 percent through the use of standardized high-quality physical education programs, the average time per day would increase to 15 minutes and 23 minutes for elementary and middle school students, respectively. High school students also average 2 days per week of physical education classes (Delva et al., 2006). If the proportion of time they spent in vigorous- or moderate-intensity physical activity during physical education were assumed to be similar to that for primary school students, they would average 4 minutes per day currently, 16 minutes per day if they attended the classes daily, and 23 minutes per day if the classes were both daily and of high quality (see Table 2-1). These estimates are a bit lower than those in a recent analysis (Bassett et al., 2013).

TABLE 2-1. Estimated Current and Potential Minutes of Vigorous-or Moderate-Intensity Physical Activity on School Days for Physical Education, Classroom Physical Activity, Recess, Total School Hours, Active Transport, and After-School Sports and Activity Programs for Elementary, Middle, and High School Students.

TABLE 2-1

Estimated Current and Potential Minutes of Vigorous-or Moderate-Intensity Physical Activity on School Days for Physical Education, Classroom Physical Activity, Recess, Total School Hours, Active Transport, and After-School Sports and Activity Programs (more...)

Classroom Physical Activity

Information is insufficient with which to estimate the amount of vigorous- or moderate-intensity physical activity in which an average student engages during usual instructional classroom time. As noted earlier, it is estimated that classroom physical activity could add 19 minutes of such activity to every school day (Bassett et al., 2013), perhaps at the primary and secondary school levels (see Table 2-1).

Recess

An estimated 97 percent of primary schools have regularly scheduled recess for about 30 minutes per day (Lee et al., 2007), and children spend roughly 30 percent of their time at recess doing vigorous- or moderate-intensity physical activity (Ridgers et al., 2005), for an estimated average time per day in vigorous- or moderate-intensity physical activity during recess of 9 minutes. As noted, enhanced-quality recess (e.g., providing age-appropriate equipment, blacktop games, adult encouragement and supervision) could add an estimated 5 minutes (Bassett et al., 2013), for a total of 14 minutes per day (see Table 2-1).

Total During School Hours

The committee found few estimates of total vigorous- or moderate-intensity physical activity or step counts during school hours. The estimates it did find are from a limited number of schools and only one in the United States (Tudor-Locke et al., 2006; Fairclough et al., 2012; Gauthier et al., 2012; Rush et al., 2012). Together, these estimates suggest that about 40 percent of the usual volume of physical activity takes place during school hours, but no estimate of the total energy expenditure or time in vigorous- or moderate-intensity physical activity was available. The estimates in Table 2-1 suggest that primary school students currently spend at least 15 minutes per school day and high school students at least 5 minutes per school day engaged in vigorous- or moderate-intensity physical activity during school hours. With high-quality daily physical education, enhanced-quality recess, and vigorous- or moderate-intensity physical activity inserted into usual classroom activities, the estimated minutes per school day would be at least 49, 57, and 42 minutes for elementary, middle, and high school students, respectively (see Table 2-1). These totals do not include vigorous-or moderate-intensity physical activity that might accrue during other parts of the school day, such as during the lunch break, or for the upper grades movement from one classroom to another.

Active Transport

Students who walk or bike to school average 16 minutes per day of vigorous- or moderate-intensity physical activity during transit (Bassett et al., 2013). Currently, approximately 13 percent of primary school students, 11 percent of middle school students, and 8 percent of high school students usually walk or bike to school (McDonald, 2007; McDonald et al., 2011). Thus, the average minutes per day of vigorous- or moderate-intensity physical activity during active transit for all students is 2 minutes for elementary and middle school students and 1 minute for high school students. Because many students live too far from school to be able to walk or bike (Falb et al., 2007; McDonald, 2007; McDonald et al., 2011), a doubling of the current prevalence of students using active transport is perhaps as much as could be expected without the creation of numerous smaller schools nearer children's homes or major changes in school busing practices. The average number of minutes for all students would then increase to 4 minutes per day for elementary and middle school students and 3 minutes per day for high school students. Of course, for those students who can walk or bike to school, active transport provides the full 16 minutes of vigorous- or moderate-intensity physical activity.

After-School Interscholastic and Intramural Sports, Physical Activity Clubs, and Other After-School Programs

Despite the growing popularity of these after-school activities, no good estimates of the number of participants exist. As noted earlier, after-school activity programs for elementary and middle school students are estimated to add 10 minutes per day of vigorous- or moderate-intensity physical activity (Bassett et al., 2013).

TRENDS IN PHYSICAL ACTIVITY BEHAVIORS AMONG YOUTH

This section reviews trends in physical activity behaviors among youth, examining in turn vigorous- or moderate-intensity activity, sedentary and light-intensity activity, and physical activity not necessarily related to school.

Vigorous- or Moderate-Intensity Physical Activity

Although estimates of children and adolescents currently achieving the recommended volume of vigorous- or moderate-intensity physical activity vary depending on how the data were collected, it is clear that few children are sufficiently physically active. An important question is whether the current status of physical activity among youth is an improvement, a worsening, or no different relative to previous years. If the situation is improving (i.e., children have been becoming more active), no changes or new efforts may be warranted; if the situation is stable or worsening, actions are needed. Few data sources provide clear and convincing evidence on trends in children's level of physical activity, but taken together the evidence is persuasive that children and adolescents in the United States have become increasingly less physically active over the past 40-50 years.

The YRBS provides self-reported information on physical activity among high school students for 1993–2011. Although the data span 20 years, trends in vigorous- or moderate-intensity physical activity are obscured because the survey questions have been modified over time to align with changes in the recommended volume of physical activity for youth (annual surveillance reports from CDC's website for 1995, 1997, 1999, 2001, 2003, 2005, 2007, 2009, and 2011) (see Figure 2-10 and Box 2-5). The largest change is an increase from 70 percent in 1995 to 84 percent in 2005 in the percentage of students who participate in physical education and who report averaging more than 20 minutes per class exercising or playing sports. In 2011 there was a sharp increase over 2009 in the proportion of students reporting at least 60 minutes of vigorous- or moderate-intensity physical activity on at least 5 days in the preceding week (37 percent to 50 percent) and a corresponding decline in the number reporting that much activity on no days of the preceding week (23 percent to 14 percent) (see Figure 2-10). These sharp changes are thought to be an artifact arising from a shift in the format of the questionnaire such that students had fewer opportunities to describe the types and amounts of their physical activity.

FIGURE 2-10. Percentage of high school students meeting physical activity recommendations, doing strength training, playing on one or more sports teams, and engaging in 20 minutes or more of vigorous- or moderate-intensity physical activity during physical education.

FIGURE 2-10

Percentage of high school students meeting physical activity recommendations, doing strength training, playing on one or more sports teams, and engaging in 20 minutes or more of vigorous- or moderate-intensity physical activity during physical education. (more...)

Box Icon

BOX 2-5

Progression of the Recommended Dose of Physical Activity for Youth. The dose of physical activity recommended for youth has changed during the past 30 years (see the table below). Initially, with little information specific to youth available, the recommended (more...)

A clear example of a decline in physical activity among youth is the decrease in the proportion of schoolchildren walking or bicycling to school. Between 1969 and 2001, this proportion dropped from 42 percent to 13 percent; among children living within 1 mile of their school, it dropped from 86 percent to 50 percent (McDonald, 2007) (see Figure 2-11).

FIGURE 2-11. Percentage of students walking or bicycling to school.

FIGURE 2-11

Percentage of students walking or bicycling to school. SOURCE: McDonald, 2007.

Sedentary or Light-Intensity Physical Activity

The above-noted evidence accumulated during the past decade indicating the health benefits of light-intensity physical activity compared with sedentary-intensity activities has spurred interest in monitoring trends in these two types of physical activity. One of the difficulties has been deciding which sedentary behaviors to monitor. Use of accelerometers in recent years has enabled researchers to measure total sedentary time, but long-term trends have depended on self-reported data, primarily regarding television viewing time and more recently also time spent watching videos, playing video games, and using a computer. Television viewing time has been monitored, often for business reasons, for a number of years. The average number of hours children and teens spent watching television daily declined slightly during the early 1990s, from about 3.3 hours per day to about 3 hours per day, and rose during the 2000s to about 3.4 hours per day (see Figure 2-12) (TVB, 2012). If television use includes DVDs, prerecorded shows, or television shows on other platforms (e.g., Internet, cell phone), then total television use has increased since the late 1990s, as has the use of computers for purposes other than schoolwork (Rideout et al., 2010). The prevalence of high school students reporting on the YRBS that they watched at least 3 hours per day of television declined from 38 percent in 2003 to 32 percent in 2011, while the prevalence of using computers for at least 3 hours per day increased from 21 percent in 2005 to 31 percent in 2011 (CDC, 2012a).

FIGURE 2-12. Hours per day spent watching television by age group, 1998–2009, and hours per day spent watching television and using computers for youth aged 8-18.

FIGURE 2-12

Hours per day spent watching television by age group, 1998–2009, and hours per day spent watching television and using computers for youth aged 8-18. NOTES: TotTV = total television content, which includes watching not only standard television (more...)

Physical Activity Not Necessarily Related to School

As noted, indirect and inferential evidence from several different types of research suggests that children and adolescents today are less physically active than previous generations. For example, comparisons with traditional cultures indicate a decline in routine physical activity. Old Order Amish and Old Order Mennonite cultures eschew modern conveniences. Comparisons of accelerometer-measured routine physical activity among children from traditional Amish and Mennonite cultures and samples of U.S. and Canadian children indicate that the former children are more physically active (Tremblay et al., 2005; Esliger et al., 2010; Hairston et al., 2012). Children from Maryland's Eastern Shore spent 53 minutes per day less in vigorous- or moderate-intensity physical activity and 34 minutes per day less in light-intensity physical activity than the Old Order Amish children with whom they were compared (Hairston et al., 2012). This translates to 87 minutes per day of sedentary physical activity.

Declines in cardiorespiratory fitness among children around the world have been documented. American researchers usually have preferred not to compare current measures of cardiorespiratory fitness among American children with results of surveys from previous years because of differing measurement methods (Pate et al., 2006a), although one review has suggested declines since the 1960s (Malina, 2007). Assessments have been performed, however, in other countries using more consistent measurement techniques, and they indicate a global decline in cardiorespiratory fitness among youth (Santtila et al., 2006; Tomkinson and Olds, 2007; Albon et al., 2010; Boddy et al., 2012; Tomkinson et al., 2012) or, in one case, a decline in physical activity behaviors (Salmon et al., 2005) (see Table 2-2). A review of evidence from around the world found that participation by youth in “active transport, physical education, and organized sports is declining in many countries” (Dollman et al., 2005, p. 892). The authors also comment that “young people would like to be active but are constrained by external factors such as school policy or curricula, parental rules in relation to safety and convenience, and physical environmental factors” (p. 892).

TABLE 2-2. Declines in Physical Fitness Among Children Around the World.

TABLE 2-2

Declines in Physical Fitness Among Children Around the World.

Finally, several studies provide empirical evidence for a gradual decline in physical activity among adults in occupational, transportation, and household tasks (Lanningham-Foster et al., 2003; Brownson et al., 2005; Church et al., 2011; Archer et al., 2013). Of interest, there is little evidence to suggest either a decrease or an increase in adult leisure-time physical activity. Although the evidence in these reports pertains to adult behavior, there can be little doubt that the declines in physical activity due to mechanization, technology, and social norms apply to children and adolescents as well.

STATE AND LOCAL POLICIES ON SCHOOL-BASED PHYSICAL ACTIVITY

As discussed in Chapter 1, schools are an important focal point for efforts to increase physical activity among children and adolescents. Accordingly, the committee examined the current state of knowledge on the status of and trends in public policies regarding school-based physical activity. Public policies are an effective tool for influencing behavioral changes at the population level as opposed to the individual level, and have been shown to have significant long-term effects on population health and health behaviors. Examples include fluoridating drinking water and requiring the use of seat belts in motor vehicles (CDC, 1999). At present, there are no federal mandates on physical activity and physical education in schools. Therefore, this section presents the committee's findings on state policies, including both statutory (legislative) and administrative (regulatory) laws, and school district wellness policies, as well as their implementation and effectiveness.

National surveillance systems contain quantitative data on the strength and comprehensiveness of these policies, developed using systematic and reliable coding systems. These data are useful for tracking both progress and changes in codified public policies of time and across jurisdictions.

Table 2-3 lists available sources of information on policies regarding school-based physical activity. The School Health Policies and Practices Study (SHPPS; Burgeson et al., 2001; Lee et al., 2007) and the Shape of the Nation Report (NASPE and AHA, 2010, 2012) provide relevant policy information collected through self-report surveys; the National Association of State Boards of Education's (NASBE's) State School Health Policy Database supplements the SHPPS with additional information on the existence of relevant state laws and policies; and the National Cancer Institute's Classification of Laws Associated with School Students (C.L.A.S.S.; Mâsse et al., 2007) and the Robert Wood Johnson Foundation–supported Bridging the Gap program (www.bridgingthegapresearch.org) compile state laws and then apply scoring systems to rank the laws in comparison with national standards and recommendations. Bridging the Gap also conducts the largest ongoing nationwide evaluation of the congressionally mandated school district wellness policies (Bridging the Gap, 2013b). The data on district wellness policies are coded using the same schemes as those used for state laws, thus enabling multilevel evaluations of the impact of district policies and state laws on school practices and student behaviors.

TABLE 2-3. Data Sources for Policies Related to School-Based Physical Activity.

TABLE 2-3

Data Sources for Policies Related to School-Based Physical Activity.

The SHPPS compiled information collected through self-report surveys for use in assessing school-based physical education and physical activity policies and practices at the state, district, school, and classroom levels. State-level data were collected from education agencies in all 50 states and the District of Columbia. District and school-level data were collected from nationally representative samples of public school districts and public and private elementary and secondary schools. Classroom-level data were collected from teachers of randomly selected classes.

The Shape of the Nation survey collects the following information on physical education: (1) time requirements; (2) high school graduation requirements; (3) exemptions/waivers and substitutions; (4) physical activity; (5) local school wellness policy; (6) standards, curriculum, and instruction; (7) class size; (8) student assessment and program accountability; (9) body mass index (BMI) collection; (10) physical education teacher certification/licensure; (11) national board certification in physical education; and (12) state physical education coordinator requirements (NASPE and AHA, 2012).

The NASBE State School Health Policy Database, begun in 1998 and continuously updated (http://www.nasbe.org/healthy_schools/hs/index.php), provides a summary description of the most recent state-level laws, legal codes, rules, regulations, administrative orders, mandates, standards, and resolutions (see Appendix C for a summary table of the laws); it does not provide historical information on laws that were in place prior to 1998.

The C.L.A.S.S. and Bridging the Gap databases vary from the NASBE database by providing scores related to the strength of policies rather than the actual policy language. They also provide historical data by year, which allows for the examination of change in state laws over time. The C.L.A.S.S. database contains state-level information in such areas as (1) physical education class time, (2) staffing requirements for physical education, (3) physical education curriculum standards, (4) assessment of health-related fitness during physical education, (5) physical activity time requirements outside of physical education, and (6) recess. C.L.A.S.S. uses a 0-4 or 0-5 rating scale, depending on the category, that captures information on the specificity, strength of language, and stringency of a law. Each year's rating reflects laws in place as of December 31. Bridging the Gap, described in detail below, collects data on both state and school district policies related to physical education and physical activity and applies a 0-3 rating scale. All sources in Table 2-3 contain information on laws for elementary, middle, and high schools. All contain some duplicative information but also other measures that are unique to that source.

Given the overlap in these data sources, the following information on state- and school district-level policies was taken from two sources—one self-reported and the other objectively collected and coded. Tables 2-4 through 2-6 present trend data for 2000–2012 on the prevalence of state-level policies related to school-based physical education and physical activity. Table 2-4 presents information extracted from the SHPPS in 2000 and 2006 (Burgeson et al., 2001; Lee et al., 2007), while Tables 2-5 and 2-6 present information compiled from Bridging the Gap (Chriqui et al., in press). Starting with the 2006–2007 school year, Bridging the Gap has compiled policies for all 50 states and the District of Columbia annually from the state law databases Westlaw and Lexis-Nexis using keyword searches. All policies are coded using a 3-point rating scale, where 0 (none) represents those states with no policy, 1 (weak) represents states with a law that suggests/encourages or imposes a less stringent requirement than the national physical activity and physical education recommendations, and 2 (strong) represents states requiring or exceeding the national recommendations. These three tables highlight only the percentage of states that have strong laws in place. The SHPPS does not use the same data coding format as Bridging the Gap; thus it is not possible to compare similar measures directly across these data sources.

TABLE 2-4. Prevalence of Policies at the State, School District, and School Levels Related to School-Based Physical Education and Physical Activity, from the School Health Policies and Practices Study (SHPPS).

TABLE 2-4

Prevalence of Policies at the State, School District, and School Levels Related to School-Based Physical Education and Physical Activity, from the School Health Policies and Practices Study (SHPPS).

TABLE 2-5. Trends in State Physical Education Policies for Elementary, Middle, and High Schools.

TABLE 2-5

Trends in State Physical Education Policies for Elementary, Middle, and High Schools.

TABLE 2-6. Trends in State Policies Related to Physical Activity for Elementary, Middle, and High Schools.

TABLE 2-6

Trends in State Policies Related to Physical Activity for Elementary, Middle, and High Schools.

Because the SHPPS (see Table 2-4) surveys relevant respondents at multiple levels, results of this survey provide information on changes in policies related to physical education and physical activity at the state, district, and school levels. These data help illustrate how policies are implemented from the state down to the school level. Because schools do not have codified policies, the self-report method of data collection can provide valuable information on the implementation and enforcement of state- and district-level policies, along with a snapshot of how schools at the local level may be implementing programs and practices beyond what they are required to do by law. In a recent study, for example, Nanney and colleagues (2010) used the SHPPS data to construct a summary scale of the number of physical activity–related policies adopted by states. They identified 146 items in the SHPPS related to physical activity and physical education and found that, on average, states had adopted 38 percent of all possible physical activity and physical education policies. However, a disadvantage of self-reported data is that they are subject to human error, such as respondent bias or misinterpretation of the survey questions, which can result in overreporting of the presence of laws, policies, and practices.

Tables 2-5 and 2-6 present annual quantitative data on trends in state policies related to physical education and physical activity, respectively, for elementary, middle, and high schools. In general, these data show that in most instances these policies at the state level have changed little during the past 6 years.

Trends in State Laws Related to Physical Education and Physical Activity

Tables 2-4 and 2-5 show an increase over time in the number of state laws addressing physical education, revealing that by school year (SY) 2011–2012 nearly all states (98 percent) across all grade levels mentioned physical education in a state-level law. However, very few states have a strong law. Only 10, 2, and 2 percent of laws, respectively, that address requirements for elementary, middle, and high schools meet national recommendations for at least 150 minutes (for elementary schools) and at least 225 minutes (for secondary schools) weekly of physical education, and virtually no change occurred in these policies from SY 2006–2007 to SY 2011–2012. Similarly, very little change has occurred across states during the past 6 years with respect to requiring daily physical education, and most states continue to allow physical education waivers, with the exception of 8, 6, and 6 percent of states, respectively, prohibiting them at the elementary, middle, and high school levels. Some positive changes in state laws have occurred, including steady increases across all grades in the number of states requiring that schools promote a physically active lifestyle and that physical education be taught by qualified instructors. Some slight change even has taken place across all grade levels in the number of states requiring a specific teacher-student ratio for physical education classes.

Currently no states require that at least 50 percent of time spent in physical education be devoted to vigorous- or moderate-intensity physical activity. Some improvement has occurred over the past 6 years in states having a requirement for any percentage of time spent in vigorous- or moderate-intensity physical activity in physical education, with elementary schools seeing the largest increase in such requirements. Further, fewer than one-quarter of all states require physical activity outside of physical education for all grade levels, and only about 1 in 5 states require daily recess at the elementary level. Requirements for physical activity outside of physical education decrease significantly at the middle and high school levels, and recess policies apply only to elementary schools. Finally, there has been a decline in the percentage of states prohibiting the use of physical activity as a punishment. Overall, the above trends reveal significant opportunities to enact and strengthen state-level physical education and physical activity laws.

Trends in States Reporting on Physical Education and Physical Activity Requirements and Fitness Assessments

Implementing laws that require a reporting mechanism is one way to monitor compliance. Table 2-7 shows trends in state and school district policies that address some kind of formal reporting to stakeholders, such as a school board, parents, or the state. The table shows that most states and districts currently do not require formal reporting on physical education and physical activity in schools. Where such a requirement exists, it may include reporting on mandatory minutes or participation rates for physical education and other school-based physical activity. For example, the law might state: “The district will report to the State Board of Education by June 15th (each year) the daily physical education/physical activity for students by school, grade, and class.” Policies may also require reporting of the results of fitness assessments (e.g., Fitnessgram®, Presidential Fitness Test, Activitygram®) to parents, the school board, or the state. The requirement might read: “Students' health-related fitness reports will be shared with parents/legal guardians at grades 5 and 8 and in high school.”

TABLE 2-7. Trends in States Mandating Reporting on Physical Education and Physical Activity Requirements and Fitness Assessments.

TABLE 2-7

Trends in States Mandating Reporting on Physical Education and Physical Activity Requirements and Fitness Assessments.

Trends in School District Wellness Policies

In addition to state laws, Bridging the Gap researchers annually collect and code congressionally mandated school district wellness policies, which are required to include physical activity goals. District wellness policies and other relevant school district policy documents (e.g., regulations, curriculum standards) are gathered annually from a nationally representative sample of school districts (N = ~600 school districts/year). Web searches are conducted, and telephone and mail follow-up with districts is used, if necessary, to identify the policies. District-level policies are coded using the same 0, 1, 2 scoring described above for state laws.

Figures 2-13 through 2-16 show that local school districts have been steadily enacting and strengthening the physical education and physical activity provisions included in local wellness policies since the policies' initial required enactment at the beginning of SY 2006–2007. Although addressing physical education is not required for local wellness policies, about 90 percent of students attend school in districts that have this provision across all grade levels.

FIGURE 2-13. Progress in adopting district wellness policies and required policy components.

FIGURE 2-13

Progress in adopting district wellness policies and required policy components. SOURCE: Chriqui et al., 2012.

FIGURE 2-14. Selected physical education provisions in district wellness policies, by year.

FIGURE 2-14

Selected physical education provisions in district wellness policies, by year. NOTE: Physical education is not a required element of wellness policies but is commonly addressed. MVPA = moderate to vigorous physical activity; PA = physical activity; PE (more...)

FIGURE 2-15. Provisions on physical education time in district wellness policies, by year and grade level.

FIGURE 2-15

Provisions on physical education time in district wellness policies, by year and grade level. NOTE: ES = elementary school; HS = high school; MS = middle school; NASPE = National Association for Sport and Physical Education; PE = physical education. SOURCE: (more...)

FIGURE 2-16. Selected physical activity provisions in district wellness policies by year.

FIGURE 2-16

Selected physical activity provisions in district wellness policies by year. NOTE: PA = physical activity; PE = physical education. SOURCE: Chriqui et al., 2012.

School districts have steadily increased the number of physical education provisions included in local wellness policies, and districts also are increasingly enacting strong provisions that require and/or are aligned with national recommendations. However, provisions on physical education continue to vary in strength. Consistent with the absence of strong state laws, few districts have implemented strong policies meeting the national standards of at least 150 physical education minutes weekly at the elementary level and at least 225 physical education minutes weekly at the middle and high school levels.

As with physical education provisions, school districts have steadily been increasing the number of other physical activity–related provisions included in wellness policies. However, fewer than 10 percent of districts include language that ensures efforts by local schools to promote safe routes to school, and only one in five districts require that communities be permitted to use school facilities for physical activities outside of school hours and prohibit withholding recess/physical education as a punishment.

Evidence showing that strong policies are associated with increased physical education and/or physical activity during the school day is growing. For example, studies conducted by Barroso and colleagues (2009), Evenson and colleagues (2009), and Kelder and colleagues (2009) show an increase in the number of weekly physical education minutes after the passage of state laws requiring daily physical education. However, implementation of state policies varied across the affected school districts (Evenson et al., 2009; Kelder et al., 2009), and some schools cited competing time demands as a barrier to full implementation (Evenson et al., 2009). More recently, Perna and colleagues (2012) examined the association between strong state laws and weekly physical education time using the C.L.A.S.S. state policy and SHPPS school-level physical education time-related measures. They found that, in states with stronger laws, 27-60 more minutes of physical education was provided weekly in elementary and middle schools compared with states with weak or no laws. However, they found no differences in weekly physical education minutes in high schools regardless of the stringency of state laws. In another study using the C.L.A.S.S. state policy data, Carlson and colleagues (2013) examined the association between the strength of state laws and the level of implementation, monitoring, and enforcement at the school level by interviewing state-level physical education coordinators. They found no policies with strong language and eight policies with moderate or weak language. They also found that none of the interviewed coordinators knew the level of implementation of the policies at the local level. In general, they found that information on school-level implementation was lacking because there were no policies in place for monitoring or enforcement. More locally, Schwartz and colleagues (2012) examined the relationship between the strength and comprehensiveness of all school district wellness policies in the state of Connecticut and school-level implementation. They found that schools located in districts with stronger, more comprehensive wellness policies were more likely to implement the policies fully. Finally, examining the association between the presence of stronger state- and district-level policies and both weekly physical education and recess minutes in elementary schools, Slater and colleagues (2012) found laws at both levels to be associated with schools providing at least 150 weekly minutes of physical education. They also found that weak state laws were associated with schools offering at least 20 minutes of daily recess. As both the SHPPS and Bridging the Gap data show, however, schools are likely to provide recess regardless of whether there is an existing state- or district-level policy requiring it.

Declining Student Enrollment in Physical Education

The data also illustrate the slippage in physical education that can occur at both the state and local levels when weaker policies in this area are enacted (see also Figure 1-3 in Chapter 1). For example, the Shape of the Nation Report (NASPE and AHA, 2012) provides a current picture of physical education in the American education system. The 2012 survey found areas of both improvement and decline in the status of physical education. As all policy data sources highlighted in this report show, the majority of states mandate physical education at all school levels. According to the Shape of the Nation Report, however, most schools do not require a specific amount of instructional time, and more than half allow exemptions, waivers, and/or substitutions for physical education. Further, the 2011 YRBS found that 48-69 percent of students did not attend physical education classes in an average week.

The Shape of the Nation Report also shows that in most states, all children in elementary and middle schools are required to take physical education when it is offered. In high school, however, students may have flexibility in when they take physical education as long as they satisfy the requirement for graduation. This flexibility creates a situation in which not all high school students take physical education at the same time. According to CDC 2011 data, in high schools where physical education was not offered daily, 68 percent of students in 9th grade, 55 percent in 10th grade, 43 percent in 11th grade, and 39 percent in 12th grade attended physical education on 1 or more days during a typical week. In schools where physical education was offered daily, 41 percent of students in 9th grade, 33 percent in 10th grade, 25 percent in 11th grade, and 24 percent in 12th grade attended daily physical education classes (CDC, 2012b). Across the nation, 52 percent of high school students attend physical education at least 1 day per week, and only 31.5 percent have daily physical education (CDC, 2012b).

Trends in Policies on After-School Programs

Before- and after-school programs offer additional opportunities to increase physical activity among youth. These opportunities also can be influenced by policy. Currently, no national surveillance system monitors the existence of such policies. However, Beets and colleagues (2010b) conducted a systematic review of state-level after-school program organizations to identify existing standards and policies, which they found in 47 states. Only about one-third of states' written documentation specifically addressed providing opportunities for physical activity during after-school programs, and only four states had comprehensive language specifying training requirements, student-staff ratios, planning/evaluation of after-school physical activity, and time allocated for physically activity. In a follow-up study, Beets and colleagues (2010a) examined the amounts of physical activity children obtained while attending after-school programs in states with comprehensive policies addressing physical activity and found that children did not meet the physical activity levels outlined in the policies. Given the variation in the language of existing policies, they suggest the need to develop a model policy for incorporating physical activity into after-school programs.

Recently, the Healthy Out of School Time Coalition was formed, consisting of individuals from major after-school program organizations and policy leaders, to develop evidenced-based Healthy Eating and Physical Activity Quality Standards for use in out-of-school-time settings. The final consensus document recommends that after-school programs provide children “with at least 30 minutes of organized, inclusive physical activity for every three hours of program time” (Wiecha et al., 2012, p. 574). In addition, the standards address policy content, provision of staff training, and appropriate program infrastructure and curriculum, as well as the provision of supportive social and physical environments.

Discrepancy Between Policy and Reality

Recent data (NASPE and the AHA, 2010) show that, although many states mandate that physical education be included in the school curriculum, schools seldom adhere to specific guidelines regarding time allocation (McCullick et al., 2012). Moreover, although elementary, middle, and high school students report meeting the national recommendation for minutes per week or per day of physical education, this may not be true in actuality. On the school schedule, the minutes allotted for physical education may be presented and reported, but the actual number of minutes in which students are engaged in physical education remains undocumented. Nor is it clear whether the time allotted for physical education was canceled or shortened on a weekly basis because of assemblies, disciplinary actions, or other school activities. Seldom are time allocations for physical education enforced or are schools held accountable for policy enforcement.

Overall, policies requiring increased physical education and physical activity at school each day have the potential to affect large numbers of children and adolescents and are an effective strategy for promoting regular physical activity. However, external and internal barriers to policy implementation need to be considered, as is highlighted by a recent study (Amis et al., 2012) finding that priority given to standardized testing and varsity sports over physical education, as well as insufficient resources and inundation with new policy requirements, serve as barriers to successful implementation of strong policies on physical activity. These findings are supported by results of a study conducted with California school board members (Cox et al., 2011), who cited most frequently as barriers to policy implementation a lack of adequate funding; limited time during the school day; and competing priorities, such as core curriculum classes and standardized testing. (See the discussion of these issues in Chapters 5 and 6.)

Existing evidence also shows some grade-level, racial/ethnic, and socio-economic disparities in participation in physical education across secondary schools (i.e., grades 8-12). Johnston and colleagues (2007) conducted a national study of 504 middle/junior high and high schools from a representative sample of geographic (urban/rural) and regional locations. The overall requirement for participation in physical education was found to drop sharply from 8th to 12th grade—87 percent in 8th grade, 47 percent in 10th grade, and 20 percent in 12th grade. The evidence also indicates a significant decrease in the minutes per week of physical education—from 172.3 minutes per week in 8th grade, to 163.9 minutes in 10th grade, to 88.6 minutes in 12th grade. The number of days per week on which students in 8th, 10th, and 12th grades receive physical education also was found to decline from 3.5 to 2.7 to 1.4 days, respectively.

From 8th to 12th grade, moreover, the percentage of students taking physical education was found to be lower in schools attended by Hispanic students than in those attended by white students; no significant differences were found for African American students (Johnston et al., 2007). Johnston and colleagues also found that schools with a greater percentage of students of higher socioeconomic status were more likely to require students to take physical education and actually have students take it than schools with a greater percentage of students of lower socioeconomic status. These findings suggest that differences do exist in the provision of physical education across grades, race/ethnicity, and socioeconomic status in secondary schools. In general, however, data on differences in the percentage of students taking physical education by race/ethnicity and socioeconomic status are sparse. Thus while it is important that schools closely examine and address such disparities, there is also a need to examine these disparities more closely.

SUMMARY

Few children in the United States, probably no more than half, meet the guideline of at least 60 minutes of vigorous- or moderate-intensity physical activity daily. The reason this statistic cannot be more specific is that different measurement methods yield different estimates. Some consistent patterns can be reported, however. The proportion meeting the guideline declines with age, with more elementary school children than middle and high school students achieving the goal, and boys are more likely than girls to meet the guideline regardless of whether the information is self-reported or derived from objective measurement with accelerometers or pedometers. There are no consistent patterns across different racial/ethnic or socio-economic groups, although fewer data are available with which to examine these issues. One can also say with reasonable certainty that over the past 30-40 years, probably even longer, the volume and intensity of daily physical activity among youth have gradually declined.

During about half of their waking hours, youth engage in activities with low rates of energy expenditure—1.5 METs or less—commonly called sedentary activities. Evidence is clear for adults and is accumulating for children that shifting time spent in sedentary activities to even light-intensity physical activity is beneficial from a health perspective.

Remarkably little information exists about the physical activity behaviors of students during school hours or in school-related activities. Even the nation's best public health surveillance systems do not obtain that information. Aside from a few good one-time surveys of physical activity during physical education classes, little information is available on students' physical activity during the school day or in after-school programs. This lack of information is surprising given that school-related physical activity must be a large component of the overall volume of physical activity among youth and that vigorous- or moderate-intensity physical activity is vital to students' healthy growth and development and is associated with improved academic performance and classroom behavior (see Chapters 3 and 4). Substantial evidence exists that the volume of student's vigorous- or moderate-intensity physical activity can be increased through daily physical education, recess, classroom physical activity, active transport to school, and before- and after-school activities (see Chapter 6).

State- and district-level policies related to physical activity have the potential to exert a positive influence on the physical activity behaviors of large numbers of children and adolescents. Evidence that such policies have not only potential but actual influence is emerging. Also emerging is evidence of slippage between the intent and implementation of these policies, such that their ultimate impact is commonly less, sometimes appreciably so, than expected. The factors that create an effective policy are still being elucidated. Policies that include required reporting of outcomes, provision of adequate funding, and easing of competing priorities appear to be more likely to be effective, as well as implemented, compared with policies that lack these features. Further evaluation of policies on physical activity and physical education is needed to fully understand their impact in changing health behavior.

Monitoring of state and district policies has improved over the past decade. In general, the number of states and districts with policies pertaining to physical education has increased, although many such policies remain weak. For example, most states and districts have policies regarding physical education, but few require daily physical education or a minimum number of minutes of physical education per week. Although some comprehensive national guidelines exist, more are needed to define quality standards for school-based physical activity policies so that more uniform programs and practices can be created across states, school districts, and ultimately schools.

An important need going forward will be augmentation of the few monitoring systems that exist for school-related physical activity behaviors. It is important to know not only how much vigorous- or moderate-intensity physical activity youth are performing but also how much of that activity is taking place in each segment of the school day (i.e., physical education, recess, classroom, transport to and from school, school-related before- and after-school activities). The YRBS, the NHANES, and Monitoring the Future provide much useful information but not enough about physical activity during and related to school. Such national surveys are not designed to provide local or even state estimates. State departments of education, local school districts, and state and local health departments will need to collaborate to provide adequate monitoring.

Finally, in addition to improved monitoring of physical activity behaviors, there is a need for augmented monitoring of physical activity–related guidelines, policies, and practices at the federal, state, and local levels. Surveillance of both student behavior and policy is necessary.

REFERENCES

  • ACSM (American College of Sports Medicine). Opinion statement on physical fitness in children and youth. Medicine and Science in Sports and Exercise. 1988;20:422–423.
  • Albon HM, Hamlin MJ, Ross JJ. Secular trends and distributional changes in health and fitness performance variables of 10-14-year-old children in New Zealand between 1991 and 2003. British Journal of Sports Medicine. 2010;44(4):263–269. [PubMed: 18487256]
  • Amis JM, Wright PM, Dyson B, Vardaman JM, Ferry H. Implementing childhood obesity policy in a new educational environment: The cases of Mississippi and Tennessee. American Journal of Public Health. 2012;102(7):1406–1413. [PMC free article: PMC3478004] [PubMed: 22420819]
  • Anderson SE, Economos CD, Must A. Active play and screen time in US children aged 4 to 11 years in relation to sociodemographic and weight status characteristics: A nationally representative cross-sectional analysis. BMC Public Health. 2008;8(1):366. [PMC free article: PMC2605460] [PubMed: 18945351]
  • Archer E, Shook RP, Thomas DM, Church TS, Katzmarzyk PT, Hébert JR, McIver KL, Hand GA, Lavie CJ, Blair SN. 45-year trends in women's use of time and household management energy expenditure. PLOS ONE. 2013;8(2):e56620. [PMC free article: PMC3577846] [PubMed: 23437187]
  • Barroso CS, Kelder SH, Springer AE, Smith CL, Ranjit N, Ledingham C, Hoelscher DM. Senate bill 42: Implementation and impact on physical activity in middle schools. Journal of Adolescent Health. 2009;45(3 Suppl):S82–S90. [PMC free article: PMC2903960] [PubMed: 19699442]
  • Bassett DR, Fitzhugh EC, Heath GW, Erwin PC, Frederick GM, Wolff DL, Welch WA, Stout AB. Estimated energy expenditures for school-based policies and active living. American Journal of Preventive Medicine. 2013;44(2):108–113. [PubMed: 23332325]
  • Beets MW, Wallner M, Beighle A. Defining standards and policies for promoting physical activity in afterschool programs. Journal of School Health. 2010a;80(8):411–417. [PubMed: 20618624]
  • Beets MW, Rooney L, Tilley F, Beighle A, Webster C. Evaluation of policies to promote physical activity in afterschool programs: Are we meeting current benchmarks. Preventive Medicine. 2010b;51(3):299–301. [PubMed: 20637796]
  • Belsky J, Booth C, Bradley R, Brownell CA, Campbell SB, Clarke-Stewart A, Friedman SL, Hirsh-Pasek K, Houts RM, Huston A, Knoke B, McCartney K, McKenzie TL, Morrison F, Nader PR, O'Brien M, Payne C, Parke RD, Owen M. Tresch, Phillips D, Pianta R, Spieker S, Vandell DL, Robeson WW, Weinraub M. Frequency and intensity of activity of third-grade children in physical education. Archives of Pediatrics and Adolescent Medicine. 2003;157(2):185–190.
  • Boddy LM, Fairclough SJ, Atkinson G, Stratton G. Changes in cardiore-spiratory fitness in 9- to 10.9-year-old children: SportsLinx 1998–2010. Medicine and Science in Sports and Exercise. 2012;44(3):481. [PubMed: 21814150]
  • Bridging the Gap. Complete descriptive statistics on state school nutrition, physical activity, and wellness policy-related laws, school years 2006–07 through 2012–13. Chicago, IL: Bridging the Gap, Health Policy Center, Institute for Health Research and Policy, University of Illinois at Chicago; 2013a. http://www​.bridgingthegap.org.
  • Bridging the Gap. District wellness policies. 2013b. [April 12, 2013]. http://www​.bridgingthegapresearch​.org/research​/district_wellness_policies.
  • Brownson RC, Boehmer TK, Luke DA. Declining rates of physical activity in the United States: What are the contributors. Annual Review of Public Health. 2005;26:421–443. [PubMed: 15760296]
  • Burgeson CR, Wechsler H, Brener ND, Young JC, Spain CG. Physical education and activity: Results from the school health policies and programs study 2000. Journal of School Health. 2001;71(7):279–293. [PubMed: 11586871]
  • Carlson JA, Sallis JF, Chriqui JF, Schneider L, McDermid LC, Agron P. State policies about physical activity minutes in physical education or during school. Journal of School Health. 2013;83(3):150–156. [PubMed: 23343315]
  • Carson V, Janssen I. Volume, patterns, and types of sedentary behavior and cardio-metabolic health in children and adolescents: A cross-sectional study. BMC Public Health. 2011;11 [PMC free article: PMC3112118] [PubMed: 21542910]
  • Caspersen CJ, Powell KE, Christenson GM. Physical activity, exercise, and physical fitness: Definitions and distinctions for health-related research. Public Health Reports. 1985;100(2):126. [PMC free article: PMC1424733] [PubMed: 3920711]
  • CDC (Centers for Disease Control and Prevention). Ten great public health achievements—United States, 1900–1999. Morbidity and Mortality Weekly Report. 1999;48(12):241–243. [PubMed: 10220250]
  • CDC. Physical activity levels among children aged 9-13 years—United States, 2002. Morbidity and Mortality Weekly Report. 2003;52:785–788. [PubMed: 12931076]
  • CDC. Nutrition, physical activity, & obesity data & statistics. 2012a. [January 13, 2013]. http://www​.cdc.gov/healthyyouth​/npao/data.htm.
  • CDC. Youth risk behavior surveillance: United States, 2011. Morbidity and Mortality Weekly Report. 2012b;61(4):1–162. [PubMed: 22673000]
  • Chiriqui JF. It's time to update your wellness policy: How does your policy compare to policies nationwide. Chicago, IL: Bridging the Gap, Health Policy Center, Institute for Health Research and Policy, University of Illinois at Chicago; 2012. [April 10, 2013]. (Webinar presentation for Illinois Department of Public Health “We Choose Health” Initiative, Illinois Maternal and Child Health Coalition, December 18, 2012). http://www​.bridgingthegapresearch​.org/_asset​/68byty/Chriqui_IDPH_2012_wellne.
  • Church TS, Thomas DM, Tudor-Locke C, Katzmarzyk PT, Earnest CP, Rodarte RQ, Martin CK, Blair SN, Bouchard C. Trends over 5 decades in US occupation-related physical activity and their associations with obesity. PLOS ONE. 2011;6(5):e19657. [PMC free article: PMC3102055] [PubMed: 21647427]
  • Cox L, Berends V, Sallis JF, St. John JM, McNeil B, Gonzalez M, Agron P. Engaging school governance leaders to influence physical activity policies. Journal of Physical Activity & Health. 2011;8(Suppl 1):S40–S48. [PubMed: 21350261]
  • Delva J, O'Malley PM, Johnston LD. Racial/ethnic and socioeconomic status differences in overweight and health-related behaviors among American students: National trends 1986–2003. Journal of Adolescent Health. 2006;39(4):536–545. [PubMed: 16982389]
  • Dollman J, Norton K, Norton L. Evidence for secular trends in children's physical activity behaviour. British Journal of Sports Medicine. 2005;39(12):892–897. [PMC free article: PMC1725088] [PubMed: 16306494]
  • Ekelund U, Luan J, Sherar LB, Esliger DW, Griew P, Cooper A. Moderate to vigorous physical activity and sedentary time and cardiometabolic risk factors in children and adolescents. Journal of the American Medical Association. 2012;307(7):704–712. [PMC free article: PMC3793121] [PubMed: 22337681]
  • Epstein D. Measuring inequity in school funding. Washington, DC: Center for American Progress; 2011.
  • Esliger DW, Tremblay MS, Copeland JL, Barnes JD, Huntington GE, Bassett DR Jr. Physical activity profile of Old Order Amish, Mennonite, and contemporary children. Medicine and Science in Sports and Exercise. 2010;42(2):296–303. [PubMed: 19927029]
  • Evenson KR, Ballard K, Lee G, Ammerman A. Implementation of a school-based state policy to increase physical activity. Journal of School Health. 2009;79(5):231–238. [PubMed: 19341442]
  • Fairclough SJ, Beighle A, Erwin H, Ridgers ND. School day segmented physical activity patterns of high and low active children. BMC Public Health. 2012;12(1):406. [PMC free article: PMC3434066] [PubMed: 22672654]
  • Fakhouri TH, Hughes JP, Brody DJ, Kit BK, Ogden CL. Physical activity and screen-time viewing among elementary school-aged children in the United States from 2009 to 2010. Journal of the American Medical Association. 2013;167(3):223–229. [PubMed: 23303439]
  • Falb MD, Kanny D, Powell KE, Giarrusso AJ. Estimating the proportion of children who can walk to school. American Journal of Preventive Medicine. 2007;33(4):269–275. [PubMed: 17888852]
  • Gauthier AP, Laurence M, Thirkill L, Dorman SC. Examining school-based pedometer step counts among children in grades 3 to 6 using different timetables. Journal of School Health. 2012;82(7):311–317. [PubMed: 22671947]
  • Gortmaker SL, Lee R, Cradock AL, Sobol AM, Duncan DT, Wang YC. Disparities in youth physical activity in the United States: 2003–2006. Medicine and Science in Sports and Exercise. 2012;44(5):888–893. [PubMed: 22089478]
  • Grøntved A, Hu FB. Television viewing and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: A meta-analysis. Journal of the American Medical Association. 2011;305(23):2448–2455. [PMC free article: PMC4324728] [PubMed: 21673296]
  • Hairston KG, Ducharme JL, Treuth MS, Hsueh WC, Jastreboff AM, Ryan KA, Shi X, Mitchell BD, Shuldiner AR, Snitker S. Diabetes Care. 2012. Comparison of BMI and physical activity between Old Order Amish children and non-Amish children. epub ahead of print. [PMC free article: PMC3609522] [PubMed: 23093661]
  • HealthyPeople.gov. Physical activity. 2012. [February 25, 2013]. http://www​.healthypeople​.gov/2020/topicsobjectives2020​/objectiveslist​.aspx?topicId=33.
  • Healy GN, Dunstan DW, Salmon J, Cerin E, Shaw JE, Zimmet PZ, Owen N. Breaks in sedentary time beneficial associations with metabolic risk. Diabetes Care. 2008a;31(4):661–666. [PubMed: 18252901]
  • Healy GN, Dunstan DW, Salmon J, Shaw JE, Zimmet PZ, Owen N. Television time and continuous metabolic risk in physically active adults. Medicine and Science in Sports and Exercise. 2008b;40(4):639. [PubMed: 18317383]
  • HHS (U.S. Department of Health and Human Services). Promoting health/preventing disease: Objectives for the nation. Washington, DC: HHS; 1984.
  • HHS. Physical activity and health: A report of the Surgeon General. Atlanta, GA: HHS, CDC, National Center for Chronic Disease Prevention and Health Promotion; 1996.
  • HHS. Physical activity guidelines for Americans. Washington, DC: HHS; 2008.
  • Hu FB, Li TY, Colditz GA, Willett WC, Manson JE. Television watching and other sedentary behaviors in relation to risk of obesity and type 2 diabetes mellitus in women. Journal of the American Medical Association. 2003;289(14):1785–1791. [PubMed: 12684356]
  • IOM (Institute of Medicine). Accelerating progress in obesity prevention: Solving the weight of the nation. Washington, DC: The National Academies Press; 2012. [PMC free article: PMC3648752] [PubMed: 22983849]
  • Janz KF, Burns TL, Levy SM. Tracking of activity and sedentary behaviors in childhood: The Iowa Bone Development Study. American Journal of Preventive Medicine. 2005;29(3):171–178. [PubMed: 16168865]
  • Johnston LD, Delva J, O'Malley PM. Sports participation and physical education in American secondary schools. Current levels and racial/ethnic and socio-economic disparities. American Journal of Preventive Medicine. 2007;33(4 Suppl):S195–S208. [PubMed: 17884568]
  • Katzmarzyk PT, Church TS, Craig CL, Bouchard C. Sitting time and mortality from all causes, cardiovascular disease, and cancer. Medicine and Science in Sports and Exercise. 2009;41(5):998–1005. [PubMed: 19346988]
  • Kelder SH, Springer AE, Barroso CS, Smith CL, Sanchez E, Ranjit N, Hoelscher DM. Implementation of Texas Senate Bill 19 to increase physical activity in elementary schools. Journal of Public Health Policy. 2009;30:S221–S247. [PMC free article: PMC2917835] [PubMed: 19190576]
  • Kohl HW III, Hobbs KE. Development of physical activity behaviors among children and adolescents. Pediatrics. 1998;101(Suppl 2):549–554. [PubMed: 12224661]
  • Lanningham-Foster L, Nysse LJ, Levine JA. Labor saved, calories lost: The energetic impact of domestic labor-saving devices. Obesity. 2003;11(10):1178–1181. [PubMed: 14569042]
  • Lee SM, Burgeson CR, Fulton JE, Spain CG. Physical education and physical activity: Results from the School Health Policies and Programs Study 2006. Journal of School Health. 2007;77(8):435–463. [PubMed: 17908102]
  • Malina R. Physical fitness of children and adolescents in the United States: Status and secular change. Medicine and Sport Science. 2007;50:67–90. [PubMed: 17387252]
  • Mâsse LC, Chriqui JF, Igoe JF, Atienza AA, Kruger J, Kohl HW III, Frosh MM, Yaroch AL. Development of a Physical Education-Related State Policy Classification System (PERSPCS). American Journal of Preventive Medicine. 2007;33(4 Suppl):S264–S276. [PubMed: 17884575]
  • Matthews CE, Chen KY, Freedson PS, Buchowski MS, Beech BM, Pate RR, Troiano RP. Amount of time spent in sedentary behaviors in the United States, 2003–2004. American Journal of Clinical Nutrition. 2008;167(7):875–881. [PMC free article: PMC3527832] [PubMed: 18303006]
  • Matthews CE, George SM, Moore SC, Bowles HR, Blair A, Park Y, Troiano RP, Hollenbeck A, Schatzkin A. Amount of time spent in sedentary behaviors and cause-specific mortality in U.S. adults. American Journal of Clinical Nutrition. 2012;95(2):437–445. [PMC free article: PMC3260070] [PubMed: 22218159]
  • McCullick BA, Baker T, Tomporowski PD, Templin TJ, Lux K, Isaac T. An analysis of state physical education policies. Journal of Teaching in Physical Education. 2012;31(2):200–210.
  • McDonald NC. Active transportation to school: Trends among U.S. schoolchildren 1969–2001. American Journal of Preventive Medicine. 2007;32(6):509–516. [PubMed: 17533067]
  • McDonald NC, Brown AL, Marchetti LM, Pedroso MS. U.S. school travel, 2009: An assessment of trends. American Journal of Preventive Medicine. 2011;41(2):146–151. [PubMed: 21767721]
  • McKenzie TL, Sallis JF, Nader PR. SOFIT: System for Observing Fitness Instruction Time. Journal of Teaching in Physical Education. 1991;11(2):195–205.
  • McKenzie TL, Nader PR, Strikmiller PK, Yang M. School physical education: Effect of the Child and Adolescent Trial for Cardiovascular Health. Preventive Medicine. 1996;5(4):423–431. [PubMed: 8818066]
  • McKenzie TL, Catellier DJ, Conway T, Lytle LA, Grieser M, Webber LA, Pratt CA, Elder JP. Girls' activity levels and lesson contexts in middle school PE: TAAG baseline. Medicine and Science in Sports and Exercise. 2006;38(7):1229. [PMC free article: PMC2431981] [PubMed: 16826019]
  • Nader PR, Bradley RH, Houts RM, McRitchie SL, O'Brien M. Moderate-to-vigorous physical activity from ages 9 to 15 years. Journal of the American Medical Association. 2008;300(3):295–305. [PubMed: 18632544]
  • Nanney MS, Nelson T, Wall M, Haddad T, Kubik M, Laska MN, Story M. State school nutrition and physical activity policy environments and youth obesity. American Journal of Preventive Medicine. 2010;38(1):9. [PMC free article: PMC3273864] [PubMed: 20117552]
  • NASPE (National Association for Sport and Physical Education) and AHA (American Heart Association). Shape of the nation report: Status of physical education in the USA. Reston, VA: NASPE; 2010.
  • NASPE and AHA. Shape of the nation report: Status of physical education in the USA. Reston, VA: American Alliance for Health, Physical Education, Recreation and Dance; 2012.
  • New America Foundation. School finance: Federal, state, and local K-12 school finance overview. 2012. [January 13, 2013]. http:/febp​.newamerica​.net/background-analysis/school-finance.
  • PAGAC (Physical Activity Guidelines Advisory Committee). Physical activity guidelines advisory committee report. Washington, DC: HHS; 2008.
  • Pate RR, Pratt M, Blair SN, Haskell WL, Macera CA, Bouchard C, Buchner D, Ettinger W, Heath GW, King AC. Physical activity and public health. Journal of the American Medical Association. 1995;273(5):402–407. [PubMed: 7823386]
  • Pate RR, Freedson PS, Sallis JF, Taylor WC, Sirard J, Trost SG, Dowda M. Compliance with physical activity guidelines: Prevalence in a population of children and youth. Annals of Epidemiology. 2002;12(5):303–308. [PubMed: 12062916]
  • Pate RR, Ross R, Dowda M, Trost SG, Sirard J. Validation of a 3-day physical activity recall instrument in female youth. Pediatric Exercise Science. 2003;15(3):257–265.
  • Pate RR, Wang CY, Dowda M, Farrell SW, O'Neill JR. Cardiorespiratory fitness levels among US youth 12 to 19 years of age: Findings from the 1999–2002 national health and nutrition examination survey. Archives of Pediatrics & Adolescent Medicine. 2006a;160(10):1005. [PubMed: 17018458]
  • Pate RR, Stevens J, Pratt C, Sallis JF, Schmitz KH, Webber LS, Welk G, Young DR. Objectively measured physical activity in sixth-grade girls. Archives of Pediatrics & Adolescent Medicine. 2006b;160(12):1262–1268. [PMC free article: PMC2443855] [PubMed: 17146024]
  • Pate RR, Mitchell JA, Byun W, Dowda M. Sedentary behaviour in youth. British Journal of Sports Medicine. 2011;45(11):906–913. [PubMed: 21836174]
  • Pate RR, O'Neill JR, Lobelo F. The evolving definition of “sedentary.” Exercise and Sport Science Reviews. 2008;36(4):173–178. [PubMed: 18815485]
  • Perna FM, Oh A, Chriqui JF, Mâsse LC, Atienza AA, Nebeling L, Agurs-Collins T, Moser RP, Dodd KW. The association of state law to physical education time allocation in US public schools. American Journal of Public Health. 2012;102(8):1594–1599. [PMC free article: PMC3464828] [PubMed: 22594746]
  • Powell KE, Roberts AM, Ross JG, Phillips MAC, Ujamaa DA, Zhou M. Low physical fitness among fifth- and seventh-grade students, Georgia, 2006. American Journal of Preventive Medicine. 2009;36(4):304–310. [PubMed: 19201145]
  • Powell KE, Paluch AE, Blair SN. Physical activity for health: What kind? How much? How intense? On top of what. Annual Review of Public Health. 2011;32:349–365. [PubMed: 21128761]
  • Rideout V, Foehr UG, Roberts DF. Generation M2: Media in the lives of 8- to 18-year-olds. Washington, DC: Kaiser Family Foundation; 2010.
  • Ridgers ND, Stratton G, Fairclough SJ. Assessing physical activity during recess using accelerometry. Preventive Medicine. 2005;41(1):102–107. [PubMed: 15917000]
  • Ridley K, Ainsworth B, Olds T. Development of a compendium of energy expenditures for youth. International Journal of Behavioral Nutrition and Physical Activity. 2008;5(1):45. [PMC free article: PMC2564974] [PubMed: 18782458]
  • Rush E, Coppinger T, Obolonkin V, Hinckson E, McGrath L, McLennan S, Graham D. Use of pedometers to identify less active children and time spent in moderate to vigorous physical activity in the school setting. Journal of Science and Medicine in Sport. 2012;15(3):226–230. [PubMed: 22154488]
  • Sallis JF, McKenzie TL, Alcaraz JE, Kolody B, Faucette N, Hovell MF. The effects of a 2-year physical education program (SPARK) on physical activity and fitness in elementary school students. American Journal of Public Health. 1997;87(8):1328–1334. [PMC free article: PMC1381094] [PubMed: 9279269]
  • Salmon J, Timpero A, Cleland V, Venn A. Trends in children's physical activity and weight status in high and low socio-economic status areas of Melbourne, Victoria, 1985–2001. Australian and New Zealand Journal of Public Health. 2005;29(4):337–342. [PubMed: 16222931]
  • Santtila M, Kyröläinen H, Vasankari T, Tiainen S, Palvalin K, Häkkinen A, Häkkinen K. Physical fitness profiles in young Finnish men during the years 1975–2004. Medicine and Science in Sports and Exercise. 2006;38(11):1990. [PubMed: 17095934]
  • Schwartz MB, Henderson KE, Falbe J, Novak SA, Wharton CM, Long MW, O'Connell ML, Fiore SS. Strength and comprehensiveness of district school wellness policies predict policy implementation at the school level. Journal of School Health. 2012;82(6):262–267. [PMC free article: PMC3810308] [PubMed: 22568461]
  • Simons-Morton BG, Parcel GS, O'Hara NM, Blair SN, Pate RR. Health-related physical fitness in childhood: Status and recommendations. Annual Review of Public Health. 1988;9(1):403–425. [PubMed: 3288238]
  • Simons-Morton BG, Taylor WC, Snider SA, Huang IW. The physical activity of fifth-grade students during physical education classes. American Journal of Public Health. 1993;83(2):262–264. [PMC free article: PMC1694589] [PubMed: 8427337]
  • Simons-Morton BG, Taylor WC, Snider SA, Huang IW, Fulton JE. Observed levels of elementary and middle school children's physical activity during physical education classes. Preventive Medicine. 1994;23(4):437–441. [PubMed: 7971870]
  • Simons-Morton BG, McKenzie TJ, Stone E, Mitchell P, Osganian V, Strikmiller PK, Ehlinger S, Cribb P, Nader PR. Physical activity in a multiethnic population of third graders in four states. American Journal of Public Health. 1997;87(1):45–50. [PMC free article: PMC1380763] [PubMed: 9065225]
  • Sisson SB, Church TS, Martin CK, Tudor-Locke C, Smith SR, Bouchard C, Earnest CP, Rankinen T, Newton RL Jr, Katzmarzyk PT. Profiles of sedentary behavior in children and adolescents: The U.S. National Health and Nutrition Examination Survey, 2001–2006. International Journal of Pediatric Obesity. 2009;4(4):353–359. [PMC free article: PMC2891818] [PubMed: 19922052]
  • Slater SJ, Nicholson L, Chriqui J, Turner L, Chaloupka F. The impact of state laws and district policies on physical education and recess practices in a nationally representative sample of U.S. public elementary schools. Archives of Pediatrics & Adolescent Medicine. 2012;166(4):311–316. [PMC free article: PMC3523123] [PubMed: 22147763]
  • Strong WB, Malina RM, Blimkie CJ, Daniels SR, Dishman RK, Gutin B, Hergenroeder AC, Must A, Nixon PA, Pivarnik JM, Rowland T, Trost S, Trudeau F. Evidence based physical activity for school-age youth. Journal of Pediatrics. 2005;146(6):732–737. [PubMed: 15973308]
  • Tomkinson G, Olds T. Secular changes in pediatric aerobic fitness test performance: The global picture. Medicine and Sport Science. 2007;50:46–66. [PubMed: 17387251]
  • Tomkinson GR, Macfarlane D, Noi S, Kim DY, Wang Z, Hong R. Temporal changes in long-distance running performance of Asian children between 1964 and 2009. Sports Medicine. 2012;42(4):267–279. [PubMed: 22350571]
  • Torun B. Inaccuracy of applying energy expenditure rates of adults to children. American Journal of Clinical Nutrition. 1983;38(5):813–815. [PubMed: 6637872]
  • Tremblay MS, Barnes JD, Copeland JL, Esliger DW. Conquering childhood inactivity: Is the answer in the past. Medicine and Science in Sports and Exercise. 2005;37(7):1187. [PubMed: 16015137]
  • Tremblay MS, LeBlanc AG, Kho ME, Saunders TJ, Larouche R, Colley RC, Goldfield G, Gorber SC. Systematic review of sedentary behaviour and health indicators in school-aged children and youth. International Journal of Behavioral Nutrition and Physical Activity. 2011;8(1):98. [PMC free article: PMC3186735] [PubMed: 21936895]
  • Treuth MS, Catellier DJ, Schmitz KH, Pate RR, Elder JP, McMurray RG, Blew RM, Yang S, Webber L. Weekend and weekday patterns of physical activity in overweight and normal-weight adolescent girls. Obesity. 2012;15(7):1782–1788. [PMC free article: PMC2289771] [PubMed: 17636097]
  • Troiano RP, Berrigan D, Dodd KW, Mâsse LC, Tilert T, McDowell M. Physical activity in the United States measured by accelerometer. Medicine and Science in Sports and Exercise. 2008;40(1):181–188. [PubMed: 18091006]
  • Tudor-Locke C, Lee SM, Morgan CF, Beighle A, Pangrazi RP. Children's pedometer-determined physical activity during the segmented school day. Medicine and Science in Sports and Exercise. 2006;38(10):1732–1738. [PubMed: 17019294]
  • TVB (TV Basics). TV Basics. 2012. [January 13, 2013]. http://www​.tvb.org/media/file/TV_Basics​.pdf.
  • U.S. Department of Education. National Public Education Financial Survey (NPEFS). Washington, DC: U.S. Department of Education, National Center for Education Statistics, Common Core of Data (CCD); 2009.
  • Wiecha JL, Hall G, Gannett E, Roth B. Development of healthy eating and physical activity quality standards for out-of-school time programs. Childhood Obesity. 2012;8(6):572–576. [PubMed: 23181923]
  • Wijndaele K, Healy GN, Dunstan DW, Barnett AG, Salmon J, Shaw JE, Zimmet PZ, Owen N. Increased cardiometabolic risk is associated with increased TV viewing time. Medicine and Science in Sports and Exercise. 2010;42(8):1511–1518. [PubMed: 20139784]
  • Wijndaele K, Brage S, Besson H, Khaw KT, Sharp SJ, Luben R, Wareham NJ, Ekelund U. Television viewing time independently predicts all-cause and cardiovascular mortality: The European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk study. International Journal of Epidemiology. 2011;40(1):150–159. [PubMed: 20576628]
  • Wright VR, Price J, Bianchi SM, Hunt BR. The time use of teenagers. Social Science Research. 2009;38:792–809.
Image p25
Copyright 2013 by the National Academy of Sciences. All rights reserved.
Bookshelf ID: NBK201496

Views

  • PubReader
  • Print View
  • Cite this Page
  • PDF version of this title (4.4M)

Related information

  • PMC
    PubMed Central citations
  • PubMed
    Links to PubMed

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...