- Physical activity provides important health benefits to children and adolescents, but most American youth do not meet current physical activity guidelines.
- A comprehensive public health initiative is needed to increase population-level youth physical activity, and it should include evidence-based strategies applied in multiple societal sectors.
- Established public health methods should be used in implementing policies and programs that will change U.S. communities in ways that will increase physical activity in young people.
For well over a century, multiple professional groups in the United States have worked to promote physical activity (PA) and physical fitness in youth. In the late 19th century, based largely on the recommendations of highly regarded physicians, the American educational system established and ultimately institutionalized physical education for students (1). In the mid-20th century, President Eisenhower, concerned by a report that American children were less physically fit than their European counterparts, established a President’s Council on Youth Fitness. Eisenhower’s successor, John F. Kennedy, broadened the role of the Council to include promotion of physical fitness in all segments of the population, but maintained an emphasis on youth. In addressing a Conference on Physical Fitness in Youth in 1961, Kennedy said, “I want to urge that this be a matter of great priority. ‘A sound mind and a sound body’ is one of the oldest slogans of the Western World. I am hopeful that we will place a proper weight on intellectual achievement, but in my judgment, for the long-range happiness and well-being of all of you, for the strengthening of our country, for a more active and vigorous life, all of you as individuals and as groups will participate in strengthening the physical well-being of young American boys and girls.”
In retrospect, President Kennedy’s words have an ironic ring, given that American children of the 1960s were almost certainly more physically active and fit than are today’s children (2,3). Because public health surveillance systems did not include measures of PA in the 1960s, we cannot be certain of the extent to which PA levels in youth have declined over the past 60 yr. But what is certain is that, today, millions of American children are less physically active and fit than experts recommend (4,5). It is also certain that a substantial public health burden is associated with low PA in youth and that this burden includes rates of overweight and obesity that have skyrocketed over the past 30 yr (6,7).
This article is based on the premise that, for the United States and most economically developed nations, promotion of PA in children and youth constitutes one of the great public health challenges of the 21st century. Our primary purpose in this article is to lay out a comprehensive plan that we believe has the potential to meet that challenge. The plan is composed of specific strategies for which both evidence supporting intervention effectiveness and experience with implementation in large-scale applications exist. The selected strategies are applied across multiple societal sectors. Furthermore, we make the case that the plan’s ultimate success will depend upon effective application of public health methods that have succeeded in advancing the public’s health in other areas, such as tobacco control. We begin with a concise summary of the body of knowledge that constitutes the rationale for launching a large-scale public health effort to promote PA in U.S. children and youth.
PA and Health in Children and Youth
An extensive body of knowledge documents the health benefits of PA during childhood and adolescence, and the report of the 2018 Physical Activity Guidelines Advisory Committee provides an important compilation of the relevant scientific literature (8). Based on its review of studies using observational and experimental research designs, the U.S. federal advisory group concluded that maintaining higher levels of PA and increasing PA are associated with the following health benefits:
- Improved cardiorespiratory endurance and muscular fitness
- More favorable body weight and adiposity
- Improved indicators of bone health
- Improved cardiovascular and metabolic biomarkers
- Positive effects on brain health, cognition, and academic outcomes
This foundation of scientific evidence has informed the development of public health guidelines on PA for children and youth. Multiple authoritative organizations around the world have developed such guidelines, and the consensus is that school-age children and adolescents should engage in moderate-to-vigorous intensity physical activity (MVPA) for at least 1 h·d−1. Within that hour of MVPA, guidelines recommend that youth regularly engage in resistance exercise, bone-loading activities, and vigorous intensity PA (9). For children under 6 years of age, the prevailing consensus is that they should be physically active for 3 h·d−1, with the activity including intensities ranging from light to vigorous (10). Unfortunately, population surveys have shown that most children and youth in the United States do not meet these targets (4). Accordingly, there is a need to design and implement a public health initiative that will produce population-level increases in PA in children and youth.
Conceptual Basis for Promotion of PA in Children and Youth
Research studies aimed at understanding the factors that influence PA in young people have applied numerous theories of health behavior. Likewise, multiple conceptual frameworks have been developed to support planning and implementation of both research and programmatic efforts to increase PA in youth. While an in-depth discussion of these theories and frameworks is beyond the scope of this article, we provide an overview here as a means of establishing the theoretical underpinnings for the specific strategies and approaches we will recommend.
Many strategies for promoting PA in youth are designed to influence behavior of intact groups, such as students attending schools, participants in community-based recreational programs, or children living in specific communities. Nonetheless, to be successful, any PA promotion initiative must change the behavior of individual children. Accordingly, researchers have given much attention to investigating the factors that associate with or influence change in PA in studies in which the unit of randomization and analysis is the individual child. Several theories of health behavior have been particularly prominent in establishing this body of evidence, and they are summarized in the Table. Social cognitive theory (11) is perhaps the theory most widely applied in studies of PA in children and youth. This theory posits that a child’s PA behavior is influenced by the interactive effects of personal characteristics, environmental factors, and attributes of specific forms of PA (12).
In designing studies of interventions to increase PA in children, researchers frequently have applied certain conceptual frameworks. In addition, these frameworks often have been used to plan and evaluate public health interventions intended to promote children’s PA. Several of these conceptual frameworks are summarized in the Table. In particular, one of these models, the Social Ecological Model (13), has been used widely in conceptualizing public health research and practice on promoting PA in youth. Accordingly, we apply this model in organizing the recommendations presented in this article.
STRATEGIES FOR PROMOTING PA IN CHILDREN AND YOUTH
PA is a complex behavior. People engage in PA for many different reasons, in numerous settings, and in myriad forms. In children and youth, PA behavior may be even more complex than it is in older persons. It is well established that children’s PA is associated with a very wide range of personal, social environmental, and physical environmental factors (14,15). Accordingly, interventions to increase PA in youth have been implemented in many settings and have applied a wide range of approaches.
The numerous approaches to increasing PA in young people vary greatly in quality and quantity of supportive evidence. In the following sections, we will present the approaches to promoting PA that we believe warrant including in a comprehensive public health initiative to increase the PA levels of young Americans. For each of these strategies we will summarize the supportive evidence. However, we readily acknowledge that this evidence varies markedly across the strategies. In some cases, the evidence is limited to relatively small-scale efficacy studies. In other cases, the strategy has been tested in large-scale, field-based effectiveness studies. Ultimately, the strategies presented hereinafter were selected by the authors, and we recognize that this subjectivity is a limitation.
Furthermore, because our goal is to present a comprehensive plan for public health promotion of PA in U.S. youth, where possible we present initiatives that demonstrate how a strategy has been translated to broad programmatic application. For some strategies, this translational experience is quite limited, but in other cases the strategy has been applied widely and thoroughly evaluated. In all cases, it is our considered judgment that the strategy is promising and worthy of inclusion in a large-scale effort to increase PA in the population of American youth. In presenting these strategies we will use the Social Ecological Model as an organizing framework, and we will begin at the center of that model — that is, we will begin with a focus on the individual child and then transition to influences that are increasingly distal to the child. The Figure demonstrates how each strategy recommended in this article links to a level in the Social Ecological Model. Although each strategy may be viewed as aimed primarily at a particular level in the model, it is important to note that many intervention strategies influence and are influenced by phenomena operating at multiple strata in the model.
Much of the research that has identified factors that influence PA in young people has been designed to study individual children. Many of the studies have used cross-sectional designs and have identified factors that discriminate between more and less active children or adolescents (14,15). A smaller number of studies used longitudinal designs and found factors that predict future PA behavior and that mediate change in PA (20). This research has identified many discriminating factors. To briefly summarize a very large body of research, more physically active children tend to
- Enjoy physical activities
- Feel confident in their ability to engage successfully in physical activities
- Be motivated to be physically active by their concerns for appearance, achievement, or fitness
- Have parents who are tangibly supportive of their participation in physical activities
- Have friends who think PA is fun and important
- Live in homes or neighborhoods with PA resources
- Attend schools that have policies and practices that support students’ PA
- Participate in school and community-based sports and other PA programs
Although much is known about factors that influence individual children’s PA, few individually focused intervention strategies have been researched extensively or applied widely. A promising exception to that pattern is clinically based promotion of PA. Over 80% of children, ages 0 to 17, annually receive a well-child visit with a physician (21). These visits provide an opportunity for clinicians to engage in annual PA assessment and counseling with children and adolescents, and leading health organizations have recommended this approach (22–24). However, many barriers exist to counseling patients about PA in clinical settings, including lack of time, lack of reimbursement, limited clinician knowledge and skills, and lack of practical tools, administrative support systems, and systems for follow-up (25–27). Available evidence indicates that PA counseling is not yet a common practice in pediatric and family medicine clinics (27). Nonetheless, some evidence supports the efficacy of this strategy. Heath et al. (28) reported a small effect size of 0.16 for PA counseling in health care settings across all ages. Another study (29), a randomized controlled trial in adolescent boys and girls (11–15 yr), examined a primary care office-based, computer-assisted diet and PA intervention that used goal setting and brief counseling. In boys, but not girls, self-reported active days per week increased significantly in the PA group (intervention vs control, 4.1–4.4 d·wk−1 vs 3.8 to 3.8 d·wk−1). Clearly, there is a need for more research on PA interventions that target individual children, and it is recommended that such interventions explicitly target the behavioral and psycho-social factors, summarized previously, that are known to associate with children’s PA. For example, interventions based in health care settings could refer individual children to community-based PA programs that are designed to provide low-active children with enjoyable and successful PA experiences.
For this strategy, large-scale application has moved ahead, despite limited research evidence. In 2007, the American Medical Association and American College of Sports Medicine introduced an initiative to promote PA in the health care setting (30), Exercise is Medicine® (EIM). EIM calls for PA to be treated by all health care providers as a “vital sign” in every patient (31). Notably, Healthy People 2020 (32) includes a new objective (PA-11) concerning physician counseling about PA that will be monitored at the national level. One example of a health care system that has implemented a program (LiVe Well) of assessment and prescription for better health habits is Intermountain Healthcare (33). Its prescription for PA for youth, teens, and families includes a goal of achieving 60 min every day, provides examples of physical activities, and stresses limits on sitting and screen time (34).
Family and Home Setting
Because children and adolescents spend much of their time in and near their homes, it seems self-evident that the home environment exerts a powerful influence on their PA behavior. As noted previously, observational studies (14,35) have shown that the PA resources in the home (e.g., play equipment) and certain parenting behaviors influence children’s PA. Successful family/home interventions have used the following strategies: family-based goal-setting and reinforcement; focus on outcomes other than health benefits or weight loss (e.g., parents and kids spending more time together); targeting the whole family; and tailoring content to the ethnicity of the family (36).
There is evidence to support family-based interventions to increase children’s PA. One family-based intervention was designed to increase the frequency of MVPA, decrease the frequency of sedentary behaviors, and promote enjoyment and self-efficacy in PA through engaging 8- to 10-year-old African-American girls and their parents. The study found a 12% increase in MVPA following the intervention (37). However, a recent meta-analysis, based on evaluation of 47 studies, concluded that family-based interventions to increase children’s PA have produced modest effect sizes (0.41; 95% confidence interval, 0.15–0.67). Furthermore, it was concluded that the quality of the studies was highly variable and only 3 of 47 were rated as “strong” (36). Although few large-scale programs exist to engage families in physically active lifestyles, a number of organizations have developed informational packets and tool kits to help parents create PA opportunities at home. One initiative of The Y, “Healthy Family Home,” emphasizes healthy living and includes a Web site that provides families with tips, strategies, and toolkits to help them increase the amount of time they spend being active (38). Another initiative, Let’s Move Active Families, spearheaded by former First Lady Michelle Obama, provided information and action plans for parents to promote PA in their family (39).
By far, the most robust body of knowledge on promotion of PA in youth comes from research conducted in the school setting. The logic behind school-based interventions is compelling. First, such interventions have the potential to change behavior in large numbers of children, because almost all young people attend schools for most of the year, for 12 or more years. Second, because schools across the United States share a common history and regulatory framework, school-based interventions are potentially widely generalizable. In addition, the traditional school environment limits students’ PA; hence, there is a substantial opportunity to add PA to the school day. Much of the evidence on the effects of school-based PA interventions was summarized in the Physical Activity Guidelines Mid-course Report (40). That report considered interventions conducted in multiple settings and concluded that school-based strategies were the most strongly supported by the research evidence. In the following sections, we overview selected evidence-based strategies for promoting children’s PA in the school setting.
Enhanced physical education
School-based physical education has a long history in the U.S. educational system, and state-level policies have mandated that schools provide physical education to students for over a century (1). It is clear that physical education classes provide an important opportunity for students to be physically active, and recent evidence documents that physical education is widely available to U.S. students (41,42). Although physical education classes provide the opportunity for students to be physically active, studies have shown that the dose of MVPA actually provided to students is highly variable. A recent meta-analysis found that the percentage of class time during which students are active ranged from 11.4% to 88.5%, with a mean of 44.8% (43). Numerous expert panels have called for schools to increase the activity level of students in physical education classes (44), and several organizations have indicated that students should be active for at least 50% of class time.
Schools can increase the amount of time youth spend engaging in MVPA during physical education classes. One study found that girls enrolled in physical education reported more MVPA and vigorous intensity PA. Specifically, girls enrolled in physical education reported 12%–32% more 30-min blocks of MVPA and 33%–60% more 30-min blocks of vigorous intensity PA, compared with those not enrolled in physical education (45). In addition, studies have shown that modifications to physical education classes can result in increased time spent in high-intensity PA. A recent review found that providing teachers with professional development to improve instruction methods was an effective way to increase PA in physical education classes (46). One intervention study included enhanced physical education courses for elementary-school children. During the intervention, the intensity of PA during physical education classes increased, as did child-reported daily vigorous intensity PA (47). Specific strategies that have resulted in increased PA during physical education classes include adoption of class organization practices that reduce time spent standing and waiting, increasing the percentage of class members who are moving during skill practice periods, and use of devices to provide feedback to students on their activity levels (48–50).
Public agencies, nongovernment organizations, and private sector entities have taken numerous actions to enhance the quality of school physical education in the United States. Although a thorough summary of those actions is beyond the scope of this article, we will cite some notable examples. For example, although school physical education is regulated at the state and local school district levels, a recent action of the federal government may play an important role in enhancing the reach and quality of physical education. In 2015, in the context of reauthorizing the Every Student Succeeds legislation, physical education was included as a core component of a “well-rounded education” (51). This action may make new resources available to support enhancement of physical education programs, and it may establish a more robust system of accountability for those programs. In addition, some large-scale nongovernment organizations, which developed as extensions of university-based research, are working to enhance physical education. These include CATCH (47) and SPARK (50). Private sector entities have launched other initiatives, including Build Our Kids’ Success (BOKS), which is designed to complement school physical education programs (52). Importantly, some policy interventions have applied legal strategies in insuring that schools comply with state regulations in provision of physical education. For example, The City Project filed complaints under civil rights and education laws to address discrepancies in provision of physical education classes in Los Angeles. As a result, the board of education passed a resolution to enforce physical education regulations (53).
Comprehensive School Physical Activity Program
In the United States, school administrators and teachers traditionally have attached a high priority to maintaining an instructional environment that involves very little student PA. Exceptions to that pattern have included physical education and, for elementary-school students, recess breaks. However, the weekly dose of MVPA provided to students by physical education and recess is usually quite modest, and most of the typical student’s school day is dedicated to sedentary pursuits (54,55). Although this tradition is embedded deeply in the American school culture, some professional leaders are now challenging it, primarily based on the growing body of evidence that higher levels of PA and fitness are associated with higher academic achievement and improved classroom behavior (56,57).
The Comprehensive School Physical Activity Program (CSPAP) is a school-based, multicomponent approach that is designed to increase PA. Components of the CSPAP include enhanced physical education as the foundation, PA programs before and after school, classroom exercise breaks, physically active learning activities, and linkages to family and community resources. The Physical Activity Guidelines for Americans Midcourse Report found that multicomponent school-based interventions are effective at increasing PA in youth (40). In addition, a recent meta-analysis concluded that multicomponent interventions conducted in the United States have produced small, significant effects on PA levels. To date, however, no studies have examined interventions that include all five components of the CSPAP (58), and therefore the full influence of the CSPAP has not been determined. Nonetheless, this fundamental approach has been endorsed by the Institute of Medicine (IOM) (59).
The Centers for Disease Control and Prevention (CDC) and the Society of Health and Physical Educators America have published a step-by-step guide to help school districts implement multicomponent school-based interventions (58). The guide and associated training program provide physical education coordinators and teachers, classroom teachers, school administrators, recess supervisors, before and afterschool program supervisors, parents, and community members with the necessary resources and tools to develop or improve a comprehensive school PA program.
Early childhood care and education
In the United States, 61% of 3- to 4-year-old children attend preschool and other structured child development programs (60). The childcare setting can provide numerous opportunities for children to be active, but research has shown that young children spend a large percentage of their time in childcare being inactive. Pate et al. (61) used direct observation to study 3- to 5-year-old children in 24 preschools and found that approximately 87% of all observations were sedentary and only 3% were spent in MVPA. Several expert panels have recommended that children 3–5 years of age should accumulate 3 h of total PA per day (10). In one analysis based on accelerometry data, results from two preschool studies (286 children in one sample and 337 in the second) indicated that only 40%–50% of children were meeting the PA guidelines (62).
A meta-analysis of the effectiveness of 15 preschool PA interventions indicated that effect sizes were small-to-moderate for general PA and moderate for MVPA (63). The most effective programs for MVPA were interventions led by teachers, involved outdoor activity, and incorporated unstructured activity. In a recent randomized controlled trial of a preschool PA intervention (64), providing children with opportunities to be active throughout the school day increased MVPA in intervention preschools (n = 188) compared with control preschools (n = 191). Children in the intervention preschools engaged in significantly more MVPA minute per hour compared with children in control preschools (7.4 and 6.6 min·h−1, respectively).
The IOM has endorsed a goal to increase PA and decrease sedentary behaviors in young children (65). The IOM recommends that childcare regulatory agencies require childcare providers and early childhood educators to provide preschool children with opportunities to be physically active throughout the day. Every state and most U.S. territories have at least one regulation related to promoting PA in young children (66). Most states require childcare centers to provide outdoor (98% of childcare centers) and indoor environments (94% of childcare centers) that have a variety of adequate space and portable play equipment. One example of a state that has developed early childhood policies for PA is South Carolina, which implemented the “ABC Grow Healthy Physical Activity Standards” for preschools and childcare centers. These standards require teachers to plan physical activities and promote outdoor play and require centers and preschools to provide a variety of play materials to promote activity indoors and outdoors.
Children spend substantial amounts of time in community settings, and many of these settings can provide important opportunities for PA. Some community factors that influence children’s PA are structured and programmatic in nature. Others relate to neighborhood and community characteristics, such as the built environment and cultural norms. Although there is some evidence that community-wide initiatives can increase children’s PA at the population level (67), most of the relevant evidence has examined community-based programs with limited reach. In this section, we address several community-based initiatives that we believe should be included in a comprehensive public health effort to increase children’s PA.
Afterschool and summer programs
Millions of U.S. children regularly attend afterschool and summer programs. These programs vary greatly in purpose, design, and setting. Most of them have the potential to provide participants with significant doses of PA, but available evidence indicates that many do not accomplish that aim. Studies have shown that, in typical programs, children spend very limited amounts of time in MVPA (68). However, growing evidence indicates that programs can be modified so that they provide increased amounts of PA. A meta-analysis supported the conclusion that interventions in afterschool settings have produced increases in children’s PA and physical fitness (69). As an example, a randomized clinical trial demonstrated that the percentage of children meeting a PA goal was increased by an intervention that trained program leaders and staff to integrate PA into the program’s daily schedule (70).
The Y is one of the nation’s largest providers of afterschool and summer programs for youth, so it is important that The Y has implemented new standards for providing PA to participants in their programs. The Y’s Healthy Eating and Physical Activity Standards call for programs to 1) provide children with at least 30 min of PA per day; 2) include a mixture of MVPA and bone-strengthening activities; and 3) incorporate outdoor play whenever possible (71). It is encouraging that over 90% of Y facilities have committed to meeting these standards, and we recommend that standards like those adopted by The Y become the norm for providers of afterschool and summer programs.
Youth sports programs
By their nature, most youth sports programs provide participants with opportunities for PA, and the same is true for related programs such as dance and outdoor activities. Furthermore, it is clear that such programs are ingrained deeply in the fabric of American society. Research shows that participants in youth sports programs tend to be more physically active than nonparticipants (72), and youth sports participants are more likely to be active as young adults (73).
Although no comprehensive information exists on the prevalence of participation by children and youth in community and school-based sports and PA programs, the Youth Risk Behavior Surveillance System has shown that approximately 60% of U.S. high-school students participated in at least one community or school sports program during the previous year (41). This rated a score of C in the 2016 U.S. Report Card on Physical Activity for Children & Youth (74). Although overall rates of participation in such programs are almost certainly high for children of elementary and middle-school age, drop-out from youth sports programs has long been recognized as a powerful and troubling phenomenon (41). Furthermore, the doses of PA provided to participants in youth sports and other PA programs have been shown to be highly variable. Leek et al. (75) observed that children were considerably more active during soccer practices than during practices for baseball and softball, and they reported that only a small percentage of participants engaged in MVPA for at least 60 min during those practices.
Addressing these limitations of youth sports programs is the goal of the Aspen Institute’s Project Play initiative (76). Project Play aims to enhance the youth sport experience so that overall participation increases, the number of children dropping out decreases, injury rates decrease, and enjoyment of PA increases. Given the high prevalence of participation in youth sports programs, attaining the objectives of Project Play should have the effect of increasing participation rates and thereby increasing the PA levels of children at the community level. Ideally, providers of youth sports programs should tailor the strategies of Project Play to local community characteristics and then coordinate implementation of those strategies at the community level.
Walking or bicycling to and from school is potentially a very important source of PA for school-age children and youth. Research has shown that children who walk or bicycle to school manifest overall PA levels that are higher than those of nonactive commuters (77,78). However, active transport to school has become much less common than was once the case (79), and it is no longer the norm for U.S. students. In 2014, over one-half of U.S. schools reported that fewer than 10% of students walked or bicycled to school (80). Interventions aimed at increasing active transport to school have been shown to be efficacious, although effect sizes have been small (81). One promising strategy is the “walking school bus,” which involves parents walking to school with children whom they “pick up” on the route to a neighborhood school.
Although more research on policy interventions to increase children’s active transport to school is needed, an important national initiative has been established. The Safe Routes to School Partnership is a non-profit organization that works to implement, at the state and local levels, policies that support active transport to school (82). A national network of state affiliates has been created, and Safe Routes to School programs have reached many thousands of schools and millions of children (82). Safe Routes to School programs that combined educational activities with improvements to infrastructure have been evaluated and found to be successful in increasing children’s PA (83,84).
The built environment includes the neighborhoods and communities surrounding the places where children live. Creating equity in the built environment is critical, as research has shown that broad aspects of the community, including socioeconomic status, influence children’s PA. One study reported that higher socioeconomic status communities had greater odds of having PA facilities present, compared with lower socioeconomic status and minority communities. In addition, an increasing number of PA facilities was associated with decreased overweight and increased odds of participating in MVPA >5 times per week. A recent meta-analysis found a small effect on MVPA in youth of built-environment features that encouraged play, sports participation, and walking (85). A review also reported that access and proximity to recreational facilities were among the factors related to PA (86). Cohen and colleagues have shown that upgrading of public parks results in increased utilization of parks and increased PA among children using the parks (87).
A number of organizations are implementing policies and programs to improve the built environment as it relates to children and PA. One example is The City Project, which works to achieve equal justice, democracy, and livability in urban areas, particularly in California. The City Project has used advocacy efforts to improve physical activity–related disparities through activities such as the Urban Park Movement and the United Teachers of Los Angeles lawsuit (88,89). For the Urban Park Movement, The City Project provided policy and legal advocacy to help create the 40-acre Rio de Los Angeles State Park. A second organization, the Latino Health Access, is a nonprofit that seeks to improve the quality of life for underserved Latino residents in southern California. This organization has sought opportunities to address inequities in park distribution in Santa Ana, CA. Through media engagement, collection and dissemination of obesity-related surveillance data, and leveraging resources for health promotion activities, the organization was able to obtain a vacant lot in the area to re-develop into a park space for children and their families (88).
Despite the difficulties inherent in efforts to improve the built environment, the U.S. Report Card on Physical Activity for Children and Youth rated the community and the built environment a B−, the highest rating of all U.S. PA indicators (70). This grade is due to the fact that 86% of U.S. youth live in neighborhoods with at least one park or playground (53). Furthermore, the Physical Activity Guidelines Midcourse Report indicates that evidence shows that modifying aspects of the built environment positively can influence PA levels of youth (36).
Mass media campaigns have been used widely in public health education and promotion programs, both as stand-alone initiatives and as part of multicomponent efforts. Such campaigns have operated through multiple channels, including both electronic and print media. They are attractive because they provide the opportunity to reach large audiences through incidental exposure resulting from routine media use. Media campaigns have been used with numerous public health issues, and the effectiveness of these campaigns has been highly variable. The strongest evidence for the potential effectiveness of public health mass media campaigns comes from those directed at prevention of tobacco use in youth and promotion of seat belt use and avoidance of alcohol consumption while driving automobiles (90).
Media campaigns have been used to promote increased PA, both as independent intervention strategies and in tandem with point-of-decision prompts (90,91). Systematic reviews of the studies that evaluated these efforts typically have rated the effectiveness of these campaigns as “moderate,” with better outcomes associated with media campaigns that were combined with point-of-decision elements (90). A systematic review undertaken to inform The Guide to Community Preventive Services (92) concluded that stand-alone mass media campaigns have shown “modest and inconsistent effects” on self-reported PA. In addition, most PA campaigns evaluated previously have been directed toward adults.
Although media campaigns aimed at promoting PA have had limited success, one of the most effective campaigns undertaken to date was aimed at increasing PA in so-called “tweens,” children aged 10 to 13 years (93). Undertaken between 2002 and 2006, the VERB campaign was supported by a very large, one-time $339 million Congressional appropriation that enabled application of the most sophisticated media strategies (94). Extensive formative research was undertaken to guide the design of the campaign, which operated largely through cable television channels that were popular with children of the target age. An extensive evaluation of VERB showed that children’s PA increased in proportion to their exposure to the campaign (94). This important project demonstrated that, with sufficient resources, it is possible to positively influence children’s PA levels through a media campaign that functions on a national scale.
National and State Policies
Policies, enacted in the form of federal or state laws, have been critical to advancing public health in many areas. For example, laws that have reduced pollution of our air and water resources have improved the quality of the environment. Tobacco use markedly has been reduced due, in part, to laws that limit the ways in which tobacco products are marketed. In some cases, policies represent guidelines or targets, and compliance is voluntary. In other cases, compliance with a policy is technically mandatory, but the policy is not enforced effectively. Long history in public health has shown that policies are most effective in producing the desired outcome when compliance with the policy is enforced rigorously (95).
The effort to promote PA in the U.S. population has benefitted from some seminal legislative actions at both the state and federal levels. As noted previously, school-based physical education is mandated in all states. Although the nature and level of required physical education varies considerably across the states, it has been shown that children who participate in physical education more frequently are more physically active than those who participate less frequently (96), and a similar pattern has been shown across states that require varying levels of physical education exposure (97). The landmark Title IX legislation, first enacted in 1972, required that females and males be provided with equal opportunities in all educational areas, including interscholastic and intercollegiate sports. The result has been a dramatic increase in the number of girls and young women participating in school sports programs (98). Likewise, the Americans with Disabilities Act (ADA) mandates that disabled persons have access to public facilities of all kinds, including recreational facilities. By reducing or eliminating barriers to accessing such facilities, it is clear that ADA has supported increased PA in disabled persons (99–101). In the transportation domain, federal initiatives have supported Safe Routes to School and “complete streets” programs (78). Furthermore, it should be noted that federal, state, and local government entities have long invested in parks and recreation programs (102).
Beyond the specific legislative actions described previously, it is important to note that the federal government has supported PA promotion by establishing and maintaining a President’s Council on Sports, Fitness, and Nutrition (103) and by supporting the activities of a Physical Activity and Health Branch and a Division of Adolescent and School Health at the CDC. Furthermore, the Department of Health and Human Services has produced Physical Activity Guidelines for Americans in 2008 and 2018 (9,104). Although the overall federal investment in promotion of PA has been modest in comparison with the investments made in some other health areas, the activities described previously represent important steps in establishing PA as a priority in the U.S. public health system.
IMPLEMENTING A COMPREHENSIVE PUBLIC HEALTH INITIATIVE
In the previous sections, we summarized a series of strategies for promoting PA in children and youth. For each of the strategies included, research evidence supports the strategy’s potential for increasing PA, and experience in translating the strategy to broad application exists. In theory, any one of the strategies could produce, in a given child, the increase in PA needed to enable that child to meet current PA guidelines. But in practice, and when applied at the level of a community or society at large, it is very unlikely that any one strategy would generate the desired outcome. Rather, in our view, it is much more likely that a nation, region, or state will need to implement multiple strategies to move population-level PA to the desired level. Such an approach is consistent with the Social Ecological Model that was summarized earlier in this article. Furthermore, we believe that, to be successful, the strategies should be implemented in the context of a well-planned, coordinated, adequately resourced, and sustained comprehensive public health initiative. The characteristics of such an initiative are presented hereinafter.
It is possible, perhaps even likely, that the individual strategies described previously will be implemented as the result of organic developments supported by advocacy groups committed to specific initiatives. For example, groups dedicated to expanding school recess might focus only on that activity, and the same would be true for different groups interested in improving the quality of afterschool programs. Indeed, we believe that this type of advocacy will be essential to moving the strategies forward. However, we also believe that progress toward attaining the overall goal of increasing children’s PA at the population level would be accelerated by coordinated cross-sector planning at the national, state, and local levels. In the United States, this approach is represented by the National Physical Activity Plan, which is composed of evidence-based strategies, tactics, and objectives for promoting PA through initiatives in nine societal sectors (105). Some states and local regions also have developed analogous PA plans (106). Because most of the critical strategies for promoting PA in children and youth operate at the community level, we strongly endorse development of local planning groups that will focus on mobilizing community resources for promoting PA through actions in multiple sectors of society.
Focus on Equity
Compelling evidence indicates that there are marked disparities in PA levels of children and youth across population subgroups. It is well documented that, at all ages, girls tend to be less active than boys, and it is clear that PA decreases with increasing age, such that adolescents are much less active than younger children (4). Furthermore, disparities in PA have been noted across race/ethnicity groups (107) and across children and youth categorized on the basis of family socioeconomic status (108). In addition, it has been documented extensively that children’s access to PA programs and physical environmental supports for PA vary markedly across socioeconomic (109,110) and physical ability/disability groups (111). This has been shown for access to quality school physical education programs (112), community-based PA programs (109), and physical resources such as parks, green spaces, and sidewalks (110). Clearly, in the United States, the playing field is not level for all children and youth.
Elsewhere in this article, we have noted some important actions that have been aimed at reducing PA disparities. These include Title IX, which has had an enormously positive impact on girls’ access to sports programs (98), and the ADA, which has produced important benefits for young people with a wide range of disabilities. However, research on PA interventions has yielded mixed findings regarding their effectiveness with children from disadvantaged backgrounds or minority race/ethnicity groups. Based on an umbrella review, Craike et al. concluded that interventions improve PA in children from deprived settings (113). In contrast, the Healthy Communities Study found that community programs and policies to promote PA in children were associated with higher levels of PA only in children of non-Hispanic ethnicity (114). This experience suggests that special efforts will be needed to design and implement public health interventions that are effective at reducing disparities in PA across age, race, ethnicity, and socioeconomic groups of children and youth.
Surveillance is a core function of public health, and it involves systematic collection of data for the purpose of designing, evaluating, and modifying public health promotion programs (115). In the United States, systems for surveillance of PA levels in youth have existed for several decades. The Youth Risk Behavior Survey provides information on self-reported PA in high-school students on a biennial basis (37), and the National Health and Nutrition Examination Survey has used accelerometry as an objective measure of PA in children and youth on several occasions (4). However, large gaps exist in our overall youth PA surveillance system. These include limited monitoring of children at the middle- and elementary-school ages, inconsistent application of objective monitoring methods, and very limited assessment of programs and policies that influence PA in youth. Aside from regular assessment of school physical education policies (38) and participation in interscholastic sports programs (38), we currently know little about the availability and penetration of PA policies and programs (116). We recommend that surveillance systems be expanded and modified to provide for a much more complete and granular monitoring of PA levels and community-level availability of policies and programs to promote PA.
Efforts to establish a robust public health system for promoting PA should learn from public health initiatives that are already well established. Two areas that are far more established than PA are tobacco control and nutrition. For both tobacco control and nutrition, the effort to build public health capacity began decades ago and has borne considerable fruit. For tobacco control, research and advocacy efforts that began in the 1960s with the release of the first Surgeon General Report on Smoking and Health (117) have produced regulations that ban the use of tobacco products in many settings, large-scale public health education campaigns focused on health risks of tobacco use, and taxation policies that limit access to tobacco products (118). The U.S. federal dietary guidelines were first produced in 1980, and large-scale federal programs to reduce the prevalence of hunger and food insecurity are supported by enormous federal investments that are managed by a highly developed infrastructure that reaches essentially all schools and communities in the country (119,120). If we are to have the same level of success in promoting PA that we have had in fighting hunger and reducing tobacco use, we will need to build the capacity for public health action that exists for these other behaviors.
One of the most notable assets of the PA/public health community is the extensive catalog of relevant resources that have been established in communities across the country. As applied to children and adolescents, these existing resources include school sports and physical education programs; school-based PA facilities; parks and community recreation programs; youth services organizations that provide afterschool, summer, and childcare programs; youth sports organizations; faith-based organizations that provide youth programs; and health care providers, particularly pediatricians and family medicine physicians. It is enormously important that these resources exist, albeit at widely varying levels, in almost all communities in the United States. Nonetheless, new resources are needed to fully and effectively mount a comprehensive public health effort to promote increased PA levels in the population of children and youth. These resources are needed for two major purposes. In most sectors, existing resources are not currently being invested in ways that optimize the impact on children’s PA. For example, both school physical education and youth sport programs provide important opportunities for children to be physically active, but neither has been focused traditionally on optimizing participants’ activity levels during program sessions. Likewise, afterschool and summer youth programs often do not prioritize providing PA. In addition, health care providers rarely have adopted systems for assessing and counseling children and parents regarding PA.
In all of the cases cited, the necessary infrastructure exists, but the existing assets need to be redirected to optimize children’s PA. New resources will be needed to affect that redirection of those assets. Often the new resource would be invested in training and retraining of personnel. For example, in many instances, teachers, recreation specialists, youth sport coaches, providers of youth services, and health care providers need training in how to deliver state-of-the-art approaches to providing PA to children. In other cases, investments are needed to install new systems or provide physical resources that are required to support a new strategy. For example, if a youth PA program is to be modified so that most participants are active most of the time, sufficient space and equipment are needed to enable that strategy.
Building the capacity, establishing the surveillance systems, creating the plans, identifying the resources, and implementing the policies and programs needed to increase population-level PA in youth will require leadership. The effort will require leadership in all sectors and at multiple levels. Given the complexities of PA behavior, no one entity can or should “own” PA promotion at any level or in any sector. Strong leadership at the national level is needed to draw attention to the issues and is essential to implementing some of the recommended strategies. For example, designing and delivering a national media campaign on youth PA would require support from the national government, nongovernment organizations, and private sector entities. However, most of the strategies recommended in this article operate at the community level. Likewise, most of them operate within a specific societal sector. Consequently, strong leadership is most needed at the community level and, ideally, would include leaders representing multiple sectors. An attractive model is a community-level coalition that includes participation from schools, recreation commissions, faith-based organizations, health care providers, and youth service organizations. Public health agencies can play the important role of creating and managing such coalitions. Many leaders are needed, and they will be most effective when they work together in a coordinated effort.
In this article, we have presented a comprehensive public health initiative aimed at increasing the PA level of children and youth in the United States. We have summarized the scientific evidence and public health experience for a diverse set of strategies that we believe should be included in a comprehensive initiative. Furthermore, we have called for application of state-of-the-art public health methods in planning and undertaking this effort. The goal is to actualize a vision. It is a vision in which American children live in a society that sees PA as a critical factor in the health, education, and development of its young people. In such a nation, most children and youth would be highly physically active at every stage of their development as a result of planned actions that sanction and promote PA in all the key settings. Toddlers would be encouraged to explore their environment by moving throughout the day, and their activity would not be restricted unnecessarily. Preschoolers would meet their developmental milestones and prepare for kindergarten in settings that provide and promote PA as an essential strategy for both learning and health. Schools at all levels would normalize PA. Classrooms would be open, movement would be encouraged, and sedentary behavior would be discouraged. Physical education classes would see most students moving most of the time while they are exposed to and receive instruction in a wide range of activities. Outside the classroom, students would be given opportunities for activity before school starts in the morning, during regular breaks in the school day, and in a wide array of afterschool programs. When at home, children and youth would spend time outside every day, accompanied by a parent or other responsible adult as needed to ensure their safety. Summer breaks from school would see most youth consistently spending time in settings and programs that involve high levels of PA. Community agencies as well as nongovernment and faith-based organizations would offer youth sports and other PA programs that meet the needs and interests of all children, regardless of their families’ resources. And finally, communities would be designed to support PA — by active transport to school and other destinations; by recreation in parks, centers, and green spaces that are well maintained and accessible to all youth; and by delivery of community-wide campaigns and events that encourage a physically active lifestyle. Can this vision be realized? We absolutely believe that it can and will become reality. It will happen because our society’s fitness, health, and quality of life depend on it.
The authors thank Jenny Flynn Oody, Ph.D., and Gaye Groover Christmus, M.P.H., for their assistance with the development and editing of the manuscript.
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