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Faigenbaum, Avery D. Ed.D., FACSM, ACSM-EP, CSCS; MacDonald, James P. M.D., FACSM; Carvalho, Carlos Ph.D.; Rebullido, Tamara Rial Ph.D., CSPS

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ACSM's Health & Fitness Journal: 7/8 2020 - Volume 24 - Issue 4 - p 10-17
doi: 10.1249/FIT.0000000000000584
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Exercise programming to fight pediatric obesity ranked first among worldwide fitness trends in 2007 (1). Yet despite growing global deficits in physical activity among youth, topics related to youth physical activity or childhood obesity vanished from the top tier of health and fitness trends. In 2020, wearable technology was the number 1 trend, whereas exercise programming for children ranked 20th out of 38 possible trends (2). Given the cascade of adverse health and behavioral outcomes associated with physical inactivity (3), a focus on regular participation in active play, exercise, and sport activities should remain a high priority issue.

In the United States, only 24% of children and adolescents accumulate at least 60 minutes of moderate to vigorous physical activity (MVPA) daily (4), and similar trends have been reported in youth from Australia, Brazil, Ethiopia, Mexico, Portugal, and Spain (5). The decline in MVPA begins to emerge early in life and children quit playing most sports by age 11 (6,7). Physically inactive children tend to become physically inactive adolescents who replace activity time with screen time throughout their growing years (8). Findings from the Gateshead Millennium Study in the United Kingdom found that objectively measured sedentary time (i.e., sitting and screen time) increased from about half of the waking day at 7 years to more than 75% of the waking day at 15 years (8). Without regular exposure to developmentally appropriate and inherently enjoyable physical activities early in life, contemporary trends in physical inactivity are likely to continue unabated as youth become disinterested, disengaged, and disconnected from school- and community-based exercise and sport programs.

The effect of physical inactivity on lifelong pathological processes and associated health care costs has created an increasingly urgent need to identify physically inactive youth and treat them with the same energy and resolve as a child with hypertension or an adolescent with obesity. Our current approach for identifying and treating youth with exercise deficits is falling far short of expectations, and traditional “adult” health care concerns such as dynapenia, osteopenia, and cardiometabolic disorders are now being managed in contemporary youth (9,10). Without a change in our current treatment philosophy, leading to informed interventions and innovative strategies, the dire health and economic consequences of physical inactivity may continue to affect youth, their families, and population health far into the future (9).

The impact of physical inactivity on lifelong pathological processes and associated health care costs has created an urgent need to identify physically inactive youth and treat them with the same energy and resolve as a child with hypertension or an adolescent with obesity.

Youth fitness specialists are trained specialists who are well versed in kinesiology, physical development, and pediatric exercise science and are skilled in teaching youth with different needs, goals, and abilities. These professionals are uniquely positioned to challenge misperceptions associated with youth physical activity and provide needed guidance for establishing school- and community-based youth fitness programs that are safe, effective, and enjoyable (see sidebar 1). If we expand our conceptual thinking of this growing problem, we may be better prepared to address the multifactorial drivers of the inactivity pandemic. A large shift in public perceptions, programmatic strategies, and health care policies is needed to raise awareness about the importance of physical activity, to increase participation in exercise and sport, and to reduce the burden of poor health outcomes in our youth. With these concerns in mind, the aim of this article is two-fold: 1) to present the framework of the pediatric inactivity triad (PIT), a novel construct illustrating the framework of interconnected factors that drive pediatric inactivity, and 2) to describe a continuum of effective strategies for activating inactive youth so they can realize the physical, psychosocial, and cognitive benefits of regular MVPA.

The pediatric inactivity triad refers to three distinct but interrelated components that appear to drive physical inactivity in modern day youth: exercise deficit disorder, pediatric dynapenia, and physical illiteracy.

Sidebar 1:
Sidebar 1::
Misperceptions about Youth Physical Activity


The PIT refers to three distinct but interrelated components that drive physical inactivity in youth: exercise deficit disorder (EDD), pediatric dynapenia, and physical illiteracy (sidebar 2) (19). Although each of these components in isolation can affect ongoing participation in active play, exercise, and sport, collectively they present a triple jeopardy for children and adolescents that is influenced by a web of socioecological factors (Figure 1). Youth fitness specialists should understand how each individual factor of the PIT contributes to physical inactivity while recognizing the constellation of social and environmental factors that can cause a lifetime of preventable pathology (20).

Interrelated components (red) and socioecological drivers (black) of the PIT. The bidirectional arrows illustrate how conditions are related to each other. Adapted from Faigenbaum et al. (19).
Sidebar 2:
Sidebar 2::
Operational Definitions

As Figure 1 illustrates, the three components of the PIT are surrounded by socioecological drivers that can affect physical activity behaviors in children and adolescents. Children, even more so than adults, are strongly influenced by their cultural milieu. Youth attending schools that support physical education, live in communities with physical activity resources, and have parents and peers who think physical activity is fun and important tend to be more active (3,23,24). Therefore, youth fitness specialists must recognize the potential negative influence that inactive schools, communities, and parents can have on the promotion of physical activity in children and adolescents. To effect change in the child, the youth fitness specialist should work alongside parents, teachers, coaches, and health care providers.

Exercise Deficit Disorder

EDD describes a condition of reduced levels of MVPA (<60 minutes of MVPA daily) that are below recommendations consistent with positive health outcomes (10). The use of the term exercise (a planned behavior) underscores the premise that physically inactive youth need an exercise prescription that is consistent with individual needs, goals, and interests. Viewed from this perspective, generic recommendations to simply increase physical activity (e.g., “go outside and play”) are less likely to result in long-term behavior change. Because physical activity is a learned behavior that is influenced by one’s family, friends, and environment (3,23,24), youth need regular opportunities to engage in well-designed exercise and sport activities with qualified instruction so they can develop the requisite skills and abilities needed for ongoing participation.

A study of 326 children found that almost 90% of the participants with low motor competence did not accumulate at least 60 minutes of MVPA daily (25). Children with EDD who do not address movement deficiencies early in life may be unwilling or unable to engage in the recommended amount of MVPA later in life. In this sense, we need to target exercise deficits early in life with structured and innovative interventions because children are unlikely to “outgrow” physical inactivity on their own. Focusing our efforts only on youth who are overweight or obese will likely foster a symptom-oriented treatment strategy, which is less effective and more expensive than primary prevention (9). The identification and treatment of asymptomatic youth with EDD by qualified professionals is one strategy to circumvent the persistence of risky behaviors and development of pathological processes that become more difficult to manage later in life.

Pediatric Dynapenia

Another separately identifiable and treatable component of the PIT is pediatric dynapenia, a condition characterized by low levels of muscular strength and power and consequent functional limitations not caused by neurologic or muscular disease (21). Findings from a global review found adolescent participation in resistance training ranged from 0.3% in Africa to 12.4% in the Eastern Mediterranean, and participation in strength-building activities was not in the top 10 sport- and leisure-time physical activities reported (26). Although the construct of dynapenia had traditionally been associated with older adults, modern-day youth appear to be weaker and slower than previous generations and, therefore, more susceptible to the inevitable consequences of low muscular strength and power (27). Because a prerequisite level of muscular strength and power is needed to squat, jump, and sprint proficiently, weaker youth are more likely to have functional limitations and less likely to accumulate at least 60 minutes of MVPA daily (27–29). Observing weaker children on the playground or sports field supports the premise that youth with dynapenia are “awkward” movers who tend to become less engaged than their stronger peers.

Structured exercise interventions that target strength deficits are needed to prepare youth for physical activities in different settings (30). Without such interventions, the gap between weaker and stronger youth will likely widen over time with observable adverse effects on health and well-being. Epidemiological findings indicate that youth with low muscular fitness are at increased risk of maintaining a low muscular fitness level into adulthood (31). Further, muscular weakness during adolescence is associated with disability 30 years later (32). In sum, muscular weakness tends to track throughout the life course, and there is evidence for a strong association between muscular weakness early in life and disability later in life.

Physical Illiteracy

The third component of the PIT is physical illiteracy, which refers to the lack of confidence, competence, and motivation to engage in meaningful physical activities with interest and enthusiasm (22). Although higher levels of physical literacy are recognized as foundational to regular participation in MVPA throughout the life course (33), youth who are physically illiterate tend to avoid nonessential MVPA to avoid failure and humiliation (18). Without regular opportunities to learn and practice in a progressively challenging environment, youth may be less willing to play outside with friends or join a local sports team. From this perspective, the concept of physical literacy can be viewed along a continuum that may be influenced both positively and negatively by life experiences and interactions with peers, parents, teachers, coaches, and youth fitness specialists (22). Thus, exercise programming for youth is not just about accumulating the minimum threshold of MVPA daily but also about enhancing the quality of the movement experience in different settings (34). It is unlikely that youth who are physically illiterate will gain the knowledge, skills, and understanding to participate in a variety of exercise and sport activities without education, guidance, and encouragement from parents, peers, and qualified professionals.


The interrelated components of the PIT, alone or in combination, pose significant health risks to children and adolescents. The PIT represents the unhealthy end of a continuum of interrelated subthreshold conditions between physical inactivity and physical activity. On the other healthy end of that continuum, one can observe the pediatric activity triad (PAT). The components of the PAT include adequate daily MVPA, physical literacy, and muscular fitness (i.e., muscular strength, muscular power, and local muscular endurance). Figure 2 illustrates the bidirectional components of youth physical activity from PIT to PAT.

The PIT–PAT continuum of pediatric physical activity. A child’s condition may move along different arms of each spectrum of the PIT and the PAT at different rates and in either direction (dashed arrows). The bidirectional solid arrows that link each of the three conditions within PIT and PAT illustrate how they are related to one another other. Adapted from Faigenbaum et al. (19).

Youth may move from the PIT to the PAT, and within each triad move along different arms of the spectrum at different rates and in different directions. For instance, a child may progress in the domain of physical literacy, but she also may regress in terms of muscular fitness unless she participates in strength-building activities. Although there are different strategies for targeting inactive youth, the ultimate goal for every child is to remain in the PAT while making gains in each arm of that spectrum, a condition that represents an active, strong, healthy child who is physically literate.

For instance, an 8-year-old boy walks to and from school daily while not participating in any afterschool sports and seems more interested in playing video games than outdoor play. He thinks his friends can kick a ball further and run faster than him and so his interest in exercise and sport has waned. For this child, the goal is to become more active at home (e.g., bike riding and outdoor games), at school (e.g., physical education and recess), and in his community (e.g., exercise and sport activities) as he concurrently enhances his physical literacy in diverse settings. Youth fitness specialists should develop a strategy that targets all three spectra of the PIT instead of focusing only on the quantity of MVPA accumulated throughout the day. Developmentally appropriate exercises that target neuromuscular deficiencies and small group activities in a less competitive environment may help to build his competence and confidence in his physical abilities (30). Asking the child what type of physical activity he enjoys, teaching the child different movement skills, and encouraging him to create new games will help him to discover his physical skills. It is important to provide reinforcement, publicly recognize desired behaviors, and promote friendships with other children.

Although there are different strategies to move children along the continuum from the PIT to the PAT, an overarching theme involves the integration of physical, psychosocial, and cognitive processes that benefit the healthy development of each participant. Behavior change is never easy and the journey toward a physically active lifestyle needs to be developed, maintained, and embraced throughout life because youth can progress or regress along each aspect of the bidirectional continuum. Just as one may progress or regress along the five stages of change in the transtheoretical model (35), youth may be at different stages of readiness to move and learn along each arm of the PIT–PAT continuum.


Youth are not simply miniature adults. In addition to differences in physical size and physiological responses to exercise, children are active in different ways and for different reasons than older populations (3). Boys and girls tend to be physically active in short bursts of MVPA interspersed with brief rest periods, as they have fun, make friends, and create new games. Informed interventions are needed to facilitate participation in activities as youth progress from the PIT to the PAT. This is where the art of designing and implementing youth exercise programs comes into play. An understanding of pediatric exercise science needs to be balanced with an appreciation of teaching methods that motivate children to move and take responsibility for their own actions (34). Figure 3 illustrates effective strategies that youth fitness specialists may use to support youth in their journey from the PIT to the PAT.

Effective strategies to engage youth in physical activity.

This is where the art of designing and implementing youth exercise programs comes into play because the science of pediatric exercise needs to be balanced with an understanding of teaching methods that motivate children to move and take responsibility for their own actions.

New insights into the design of youth exercise programs highlight the importance of enhancing muscular fitness and improving motor skills right from the earliest stages of childhood (36,37). FUNdamental Integrative Training is a method of conditioning that incorporates developmentally appropriate strength and conditioning exercises into a lesson that is designed to enhance both health- and skill-related components of physical fitness (38). This type of training provides young participants with an opportunity to enhance muscular fitness and improve movement skills while gaining confidence and competence in their abilities to be physically active. FUNdamental Integrative Training that includes meaningful instruction, challenging exercises, and positive social interactions should be an enjoyable experience for all youth regardless of body size, physical prowess, or training experience.

Although many different exercises and program variables (i.e., sets, repetitions, and rest intervals) can be used to design FUNdamental Integrative Training programs, sessions should begin with a 5- or 10-minute dynamic warm-up. This type of engaging activity can reinforce desired movement patterns while setting the tone for the upcoming lesson. The dynamic warm-up can transition seamlessly into the training session that may include a circuit of exercises with different types of equipment (e.g., medicine balls, elastic bands, punch balloons, battling ropes, etc.). With clear demonstrations, ongoing instruction, and peer support, participants can progress from simple exercises to more complex movement patterns. Participants may create new games and exercises using the skills they have learned in a positive learning environment. For example, they could create a new strength-building exercise with medicine balls or modify a game of tag. Although the programmatic details of FUNdamental Integrative Training are beyond the scope of this article, sample programs are available elsewhere (30,39,40).


Our current efforts to engage youth in developmentally appropriate physical activity are falling short of expectations. The PIT–PAT continuum is a new theoretical framework that captures the complexity of youth physical activity. If youth fitness specialists understand the bidirectional interactions between interrelated factors of this phenomenon, they may be better prepared to keep youth moving in the right direction. Teaching youth a variety of movement skills, monitoring progress, discovering special talents, and fostering healthy behaviors in a supporting environment are all equally important strategies to spark an ongoing interest in active play, exercise, and sport activities. Concerted efforts among youth fitness specialists, school administrators, community leaders, and health care providers are needed to identify physically inactive youth, develop informed interventions, promote innovative strategies, and challenge our current approach for activating inactive youth.


Because a majority of children and adolescents worldwide are not accumulating at least 60 minutes of MVPA daily, innovative strategies are needed to activate inactive youth. The PIT, a collection of three interrelated factors that drive physical inactivity in youth, embraces the complex etiology of physical inactivity and offers a solution to better effect change. Youth fitness specialists who understand the interactions between exercise deficit disorder, pediatric dynapenia, and physical illiteracy will be better prepared to design and implement exercise interventions that sustain an ongoing interest in physical activity throughout the life course.


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        Children; Exercise; Physical Activity; Physical Literacy; Strength

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