The S.P.A.C.E Hypothesis: Physical Activity as Medium—Not Medicine—for Public Health Impact

Abstract

Most scientifically tested physical activity interventions end when research funding ends; interventions that last struggle to sustain benefits. We hypothesize that long-term public health impact will benefit from a shift in how interventionists conceptualize physical activity—from a form of medicine, of value for its innate health benefits, to a malleable medium, of value for the dynamic contexts it creates.

SUMMARY:

Embracing physical activity as a medium is proposed to overcome barriers to dissemination and implementation of scientifically tested physical activity interventions.

INTRODUCTION

In the past 50 years, total physical activity (PA) energy expenditure—including leisure-time, household, travel, and occupational PA—has fallen by 32% and weekly sedentary hours have risen from 26 to 38 (1). Concurrently, the number of overweight and obese individuals globally increased from 857-million to 2.1-billion (2), and US diabetes prevalence rose from 0.2% to 7.1% (3). In response to these trajectories, scientists and major research funders have invested in systematic investigations to develop interventions that increase PA and in turn, reduce chronic disease. The process for developing scientifically-tested interventions—referred to below as “evidence-based interventions” (EBIs)—for PA consists of a series of clinical trials based upon the translational continuum in medicine (i.e., the process of bringing medical innovations from bench-to-bedside) (4, 5).

Table 1 highlights prominent translational models for developing evidence-based health behavior interventions, including PA. For researchers, translational models begin with one to three phases to develop and pilot the intervention; these are followed by one to three phases for testing efficacy (i.e., effect on the primary outcome in ideal conditions) and effectiveness (i.e., effect on the primary outcome in real-world conditions); and finally, a phase for dissemination and implementation (6–8). This final phase of the intervention development process is the subject of its own research area: Dissemination and Implementation Science (DI). DI is dedicated to investigating the active spread of knowledge and interventions (dissemination), as well as methods to promote uptake of interventions and change practice patterns within settings (implementation) (5). These extensive processes result in proven programs with known health benefits. Practitioner models rely similarly on cycles of implementation, assessment, and refinement (9–11). Practitioners weigh the available evidence within their local environment, local population, and organizational resources to inform their best path forward, a process which may or may not include adoption and adaptation of EBIs (12).

TABLE 1.

Behavioral Intervention Development Models and Frameworks

Framework	Phase I	Phase II	Phase III	Phase IV	Phase V
Research Models
Obesity-Related Behavioral Intervention Trials (ORBIT) Model (6)	Design (Define & Refine)	Preliminary Testing (Proof-of-Concept & Pilots)	Efficacy Trial	Effectiveness Research	-
Complex Intervention Framework (7)	Preclinical – Theory, Hypothesis, Planning	Modeling	Exploratory Trial	Definitive Randomized Controlled Trial	Long-Term Implementation
Stage Model of Behavioral Intervention Development (8)	Pilot Testing	Traditional Efficacy	Efficacy Testing with Real-World Providers	Effectiveness Research	Dissemination and Implementation Research
Practitioner Models
Intervention Mapping (9)	Proximal Program Objective Matrices	Theoretical methods and Practical Strategies	Program Design	Adoption & Implementation Plan	Monitoring and Evaluation Plan
PRECEDE-PROCEED Model (10)	Assessments (Phases 1–5)	Implementation (Phase 6)	Process Evaluation (Phase 7)	Impact Evaluation	Outcome Evaluation
MAP-IT Model (11)	Mobilize	Assess	Plan	Implement	Track

The rapid growth of PA intervention research using translational models is reflected in Part F of the 2018 Federal PA Guidelines Scientific Advisory Committee report entitled, “Promoting Regular Physical Activity.” The report lists 3,259 published PA and sedentary behavior (SB) intervention studies (not mutually exclusive) cited across 92 systematic reviews and meta-analyses from 2011–2016 (13). Table 2 highlights prominent public health web portals that synthesize and consolidate research findings and implementation resources to facilitate adoption of EBIs by practitioners and communities in diverse settings. Across these repositories, 238 scientifically-tested PA interventions and intervention strategies are listed as available.

TABLE 2.

Physical Activity Interventions Featured in Evidence-Based Repositories and Web Portals

Web Portal / Registry	Sponsoring Organization(s)	Website	# of Available PA Interventions or Approaches
The Community Guide	US Department of Health and Human Services (USDHHS), Centers for Disease Control and Prevention (CDC), Community Preventive Services Task Force (CPSTF)	www.thecommunityguide.org	11 intervention approaches with sufficient evidence for implementation
Cancer Control Planet	National Cancer Institute (NCI), Centers for Disease Control (CDC), Agency for Health Research and Quality (AHRQ), Substance Abuse of Mental Health Service Administration (SAMSA), American Cancer Society, Commission on Cancer	https://cancercontrolplanet.cancer.gov/planet/	37 Research Tested Intervention Programs (RTIPs)
Community Health Online Resource Center (CHORC)	Centers for Disease Control and Prevention (CDC), National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP)	https://nccd.cdc.gov/DCH_CHORC/Default.aspx	60 tools and toolkits related to PA
Older Adults Act, Title IIID Eligible Programs	Administration for Community Living (ACL)	https://acl.gov/programs/health-wellness/disease-prevention	55 Highest-Level EBPs / Older Adults Act Title IIID Eligible Programs
What Works for Health	Robert Wood Johnson Foundation	https://www.countyhealthrankings.org/take-action-to-improve-health/what-works-for-health	26 “Scientifically Supported” Diet and Exercise Policies and Programs
Community Health Improvement Navigator	Centers for Disease Control and Prevention (CDC)	https://www.cdc.gov/CHInav/database/	49 efficacious PA intervention studies
Interventions on Diet and Physical Activity: What Works	World Health Organization	https://www.who.int/dietphysicalactivity/whatworks/en/	48 PA interventions designated “moderately effective” or “Effective”

The public health impact of a given EBI has been represented as the mathematical product of participation and effectiveness (15). For example, an intervention that reaches 100,000 individuals with each individual increasing their moderate-vigorous PA by 10-minutes per day (100,000 individuals x 10-minutes per individual = 1,000,000 minutes of moderate-vigorous PA), has precisely four-times the public health impact of one reaching 50,000 individuals with each individual increasing their moderate-vigorous PA by 5-minutes per day (50,000 individuals x 5-minutes per individual = 250,000 minutes of moderate-vigorous PA). In the medical field, dissemination and implementation has proven to be the rate limiting step for public health impact. For example, it has estimated that over a given 17-year period only 14% of research-based medical innovations translate to practice (16). Attrition of innovations across translational phases in medicine has been termed the research-practice gap, the 17-year odyssey, and [more sensationally] “the valleys of death” (16, 17).

In the context of PA intervention research, comparable attrition is evidenced by the difference between the number of published PA interventions in the scientific literature—a number in the thousands (13)—and the number of PA interventions in EBI repositories and web portals—a number in the hundreds (see Table 2). The web portals themselves are widely used—Cancer Control P.L.A.N.E.T (Plan, Link, Act, Network with Evidence-Based Tools) has had six-million visitors from more than 54 countries since its launch in 2003 (18)—but adoption of PA interventions available in these portals remains low. Surveys report that 13–37% of cancer control planners use Cancer Control P.L.A.N.E.T EBIs (19, 20), while 20–35% of state health departments [and 0–4% of local health departments] use the Community Guide for PA programming (21). Adoption rates of EBIs for PA in non-health sectors are likely even lower.

Among the minority of EBIs that are adopted in real-world settings, implementation challenges remain. The Consolidated Framework for Implementation Research (CFIR) identifies 25 influences on implementation quality related to characteristics of the intervention, setting, participants, and the implementation process (22). Implementation difficulties contribute to declining impact on primary outcomes as programs move across the translational phases of funded research, and declining benefits and discontinuation of programs when research funding ends (23). The CFIR highlights that the impact of an intervention is not based solely upon how well that intervention performed during its efficacy trial but also upon how well it fits the setting that adopts it and how well it is implemented (5, 22–24). This depends only in part on the intervention itself but more so on service contexts, networks, providers, and recipients. For example, in a recent cross-sectional study of a citywide after-school program, our research team found that staff reports of organizational culture and climate were related to parent and child reports of program quality. Program quality, in turn, was related to child social skills and problem behaviors, the program’s primary aims (25).

Across literatures, we see evidence of decreasing effects on primary outcomes as interventions progress through translational phases (5, 23, 26). To illustrate this challenge in PA intervention research, consider the findings of Hip-Hop to Health Jr., a powerful and broadly disseminated obesity prevention program for African American preschoolers. The efficacy trial of Hip-Hop to Health Jr. demonstrated that the program reduced BMI gain in half over 2 years relative to a comparison group, a significant group x time difference (27). However, in subsequent trials, one among Latino children (28) and another that was facilitated by preschool teachers rather than university staff (29), significant group x time differences were not detected.

Scientifically-tested PA interventions struggle with dissemination and implementation and these struggles limit the impact that they have on public health. This review proposes that dissemination and implementation difficulties are exacerbated by the field’s well-supported but limited view of PA as medicine [primarily of value for its innate health benefits]. It hypothesizes that a shift in perspective—the embrace of PA as medium [primarily of value for the dynamic and modifiable contexts it creates]—will mobilize intervention researchers to overcome challenges to dissemination and implementation, and thereby achieve greater public health impact. We have termed this the Spreading Physical Activity through Conceptual Expansion (S.P.A.C.E) Hypothesis. To make the case, herein we will: (a) present three modifiable challenges to dissemination and implementation of scientifically-tested PA interventions, (b) detail how embracing PA as medium can overcome these challenges to generate greater public health impact, and (c) provide examples from our own work of ongoing intervention studies embracing PA as medium. We conclude by describing how we would test the S.P.A.C.E hypothesis and discussing its implications for practice. The purpose of this review is to provide researchers and practitioners with an alternative perspective on PA that can be leveraged to improve intervention reach and impact.

CHALLENGES TO DISSEMINATION & IMPLEMENTATION OF SCIENTIFICALLY-TESTED PHYSICAL ACTIVITY INTERVENTIONS

Over the past two decades, contributing authors have directed or collaborated on 21 unique PA intervention studies in schools, parks, day care centers, community centers, and senior centers. In that time, we have encountered many challenges to dissemination and implementation but three stand out as both critical and addressable in PA intervention research.

Challenge #1: Most Scientifically-Tested PA Interventions Are Not Designed To Scale.

In a number of recent randomized clinical trials we have tested hypotheses about the effect of PA—the independent variable—on psychological outcomes—the dependent variable—among children that are overweight or obese, children with behavioral disorders, and older adults (30–33). In each case, success has been defined as statistically significant differences between groups over time on the psychological outcomes, attributable to PA. We achieved this by creating as much difference as possible in PA between groups, while carefully selecting comparison groups that isolated the effects of PA from contextual factors by controlling for staff relations, social interaction, attention, reinforcements, rules and routines, etc. (30–33). Hence, we were in equipoise (i.e., we did not know which group would perform better) about results on the dependent variables, but never the independent variable. To be certain that groups received different levels of PA, we deployed as many resources and strategies as were necessary to increase PA in treatment groups, and limit PA in comparison groups. The greater the difference we created between groups on PA, the more power we had to answer our primary question.

Unfortunately, the resources and expertise necessary to generate differences also make real-world dissemination difficult. The PRECIS-2 (PRagmatic Explanatory Continuum Indicator Summary) tool illustrates the nuances of these tradeoffs well, placing each design decision in a clinical trial (e.g., staffing, setting, inclusion criteria, comparison group, DV) on a continuum from explanatory-to-pragmatic (akin to internal vs. external validity) (34). The tool highlights the tension between decisions that ensure definitive resolution to an explanatory question (rigor) and those that promote the intervention’s eventual routine use (relevance) (34). It is generally argued that these decisions are intended to move from explanatory in early phases of the translational continuum to pragmatic in later phases, but this overlooks the profound effect that intervention and study design decisions in early phases have on the potential of the intervention to disseminate in later phases (26). Hence, PA intervention researchers often find themselves at cross-purposes, attempting to explain the effect of PA on chronic disease while simultaneously attempting to generate scalable interventions.

Challenge #2: Maintaining Fit between Static Interventions and Dynamic Settings.

Sustainable interventions must fit their settings. This principle lies at the center of influential models in DI and public health (23, 24, 35, 36). In an elegant analogy, Atkins and colleagues (2016) suggest that each setting can be conceptualized as an ecosystem and the addition of an intervention to that ecosystem disrupts homeostasis; at which point a new homeostasis must be achieved (24). The idea raises an analogy to natural selection, no specific trait is inherently good or bad, it only fits its environment or not; a polar bear’s white fur is adaptive for hunting in the snow-covered arctic but would make it too conspicuous to hunt in a North American forest. Survival is more likely for species [or intervention] that adapts quickly to shifts in the environment. Viewing PA intervention research through the lens of fit exposes a limitation inherent to traditional intervention design, development, and testing—it must occur in a specific time and place. To the extent that interventions are intended to remain static—that is, implemented in the same manner that initially worked—they will be misaligned and become obsolete as settings inevitably change over time (23, 24). Hence, “gold-standard” interventions cannot indefinitely remain so as their ecosystems change (24); and this is especially true for interventions developed with carefully selected populations under tightly controlled conditions.

Challenge #3: Important Settings Have Limited Bandwidth and Their Own Priorities.

Community-Based Participatory Research (CBPR) holds that intervention researchers must partner with stakeholders to design their programs from the outset to maximize the likelihood of adoption and sustainment (i.e., continuing with the program) (36). However, partnering with intervention researchers represents a major investment of time and resources by community organizations. Having approached many community organizations [and been rejected frequently] we have yet to encounter a single organization that did not have limited time and resources, nor one that had not already allocated them towards achieving its core priorities. For schools, this may mean academic performance; for businesses, profit or market share; for faith institutions, service; and for hospitals, readmission. PA and health may be tangential to their core goals and thereby perceived in competition with them, rather than complementary or central to them. Hence, it can be difficult for community organizations to justify allocating time, energy, and resources towards adopting, modifying, and sustaining scientifically-tested PA interventions.

Imagine a public school where statewide standardized test performance drives funding, and thus test scores are their highest priority (one degree of freedom). This does not mean that obesity and chronic disease prevention are not important, but let’s imagine that in this particular school district PA and chronic disease prevention are the sixth most important priority, behind: (1) standardized test performance, (2) grades, (3) family engagement, (4) social and emotional learning, and (5) fine arts. The interest and capacity of that school district to partner with researchers on a PA intervention [whether creating a new intervention or adopting an established one] will depend upon the extent to which they already are achieving core priorities (e.g., meeting standardized benchmarks, students performing at or above grade level, engaged parents, socially mature students, and a robust arts program) and have surplus resources (fiscal, human, space) to put towards PA and health. Hence, researchers are more likely to partner with organizations that have health high on their priority list and who already are effectively achieving their core priorities and thus well-positioned to integrate new initiatives.

In this way, our inability to align PA intervention research goals with the core goals of important settings (in the above example: test performance and grades) is a major contributor to the historical underrepresentation of racial/ethnic minority and low-income communities in intervention research. Poverty, adversity, and the contexts that generate high chronic disease are characterized by historical, systemic, pervasive and persistent stressors. Necessarily, urgent and immediate concerns take precedence over more distal and remote ones. It is difficult for organizations to invest in preventing chronic disease when homelessness, police brutality, or gang violence require most of their time, resources, and energy. In this way communities with the greatest need for PA interventions also face the largest barriers to their adoption and implementation (37). Tensions between rigor and relevance, difficulty maintaining fit, and inability to align with core setting goals limit the impact of PA intervention research on population health and exacerbate health inequities.

THE S.P.A.C.E HYPOTHESIS: EMBRACING PHYSICAL ACTIVITY AS MEDIUM TO OVERCOME CHALLENGES TO DISSEMINATION AND IMPLEMENTATION

PA is defined as any bodily movement produced by skeletal muscle that results in energy expenditure above resting levels (≥1.5 metabolic equivalent of task) (38). The characteristics of PA dose (i.e., frequency, intensity, duration, mode) are immutable. PA must occur at some frequency, at some intensity, and for some duration; it must be some proportion aerobic and anaerobic. These characteristics provide the framework for the 2018 Federal PA Guidelines, which state that adults should participate in at least 150 to 300 minutes a week of moderate-intensity (duration and intensity), or 75 to 150 minutes a week of vigorous-intensity (duration and intensity), aerobic PA (mode) spread throughout the week (frequency); with additional benefits from more moderate-vigorous aerobic and muscle strengthening activity (frequency, intensity, mode, duration) (13).

The Guidelines list 26 major health benefits with strong empirical support, these range from increased bone health to lower depression, and include reduced risk for four of the five leading causes of premature death (13). If the health benefits of PA could be put into a pill, it would be the world’s most powerful medicine. PA is our hammer and we see a world full of nails, but when important settings express that their priority is nuts and bolts, we struggle to serve them. In this section we wish to offer an expanded perspective on PA. PA is not just a hammer, PA is metal, and metal can be forged to form diverse tools that serve multiple ends.

Two decades ago, physical education luminary Dr. Don Hellison wrote, “The nature of physical activity—active, interactive, highly emotional—certainly provides the possibility of exploring and practicing values, teamwork, goal-setting, peer-teaching, conflict resolution, and so on” (p. 44) (39). His view of PA emphasized other immutable characteristics of PA reflected in social ecological frameworks—contextual factors (40). PA must occur in some context [or space]; and that context necessarily contains a range of multi-level features across physical, social, affective, cognitive, and temporal dimensions (37). Who did we exercise with? Did we win or lose? Were we cheered or booed? Did we feel proud or ashamed? These contextual factors are among the definitive determinants of our PA experiences but most often we treat them as confounds to be controlled in research studies.

Viewed from this perspective, PA is not just medicine of value for its innate health benefits. PA is also a medium, of value for the dynamic contexts it creates. PA as medicine emphasizes PA dose and form (e.g., running, swimming, punching, spinning, throwing, kicking) and the many innate health benefits that arise from participation and engagement. In contrast, PA as medium, refers to the surrounding contextual features that can be intentionally and systematically manipulated to achieve an outcome that is not already fully realized innately by the PA itself. This lens places primacy on the modifiable contexts that surround physical movement, rather than the intrinsic benefits of movement itself. Among these, sights, sounds, smells, rules, routines, feedback, strategy, expectations, dialogue, timing, reinforcements, social dynamics, emotional climate, physical environment, degree of difficulty, cognitive and emotional challenges, etc. For our purposes, the term medium extends to every feature of the PA experience other than physical movement itself. Through the lens of PA as medium the context that surrounds PA becomes a canvas upon which we can paint a range of experiences to achieve diverse ends that are not innate to PA through its conceptualization as medicine.

To comprehend the breadth of possibilities for PA as medium, consider how creative we are with contexts that surround sedentary bodies. Sedentary behavior is defined as any waking behavior characterized by an energy expenditure ≤ 1.5 metabolic equivalent of task (MET), while in a sitting, reclining or lying posture (41). The distinction between PA and sedentary behavior, then, is only the position of the body in space (sitting vs. standing) and whether the body’s position in space changes over time (unmoving vs. moving). Yet, when sedentary, we are infinitely more creative with how we use the contexts that surround us. Rarely do we sit for the sake of sitting, rather we sit in order to engage in some activity (e.g., chess, math, music, movies, drawing, meditation); the focus is on what occurs around us [and within our minds] because sitting itself has little intrinsic value. The contexts that surround moving bodies are every bit as dynamic, multi-dimensional, and important as those surrounding sedentary bodies; treating them strictly as confounders and tools to improve adherence (30–33) carries a cost for long-term dissemination and implementation of EBIs.

Figure 1 depicts the Spreading Physical Activity through Conceptual Expansion (S.P.A.C.E) Hypothesis. The S.P.A.C.E Hypothesis is intended to complement established intervention development models [reviewed in Table 1] by illustrating how embracing PA as medium at the onset of intervention research may reduce barriers to dissemination and implementation in later phases. The primary advantage of embracing PA as medium is greater versatility in intervention form and purpose. This versatility can be leveraged to align PA intervention goals with the core goals of community partners, improve yield on attempted academic-community partnerships, and improve fit between interventions and settings where partnerships are established. The increased number of partnerships, and increased fit where they are established, are hypothesized to improve DI outcomes and public health impact on PA. Figure 1 illustrates the mechanisms by which these advantages are conferred and Table 3 contrasts capacity to address DI determinants between studies viewing PA as medicine and those viewing PA as medium.

Figure 1.

The Spreading Physical Activity through Conceptual Expansion (S.P.A.C.E) Hypothesis

TABLE 3.

Contrasting PA as Medicine with PA as Medium on Determinants of Dissemination & Implementation

	Physical Activity as Medicine	Physical Activity as Medium
Perspective at Onset
Explanatory vs. Pragmatic Design Decisions	• Emphasizing inherent PA benefits aligns with explanatory designs testing the influence of PA dose characteristics on health. • Explanatory studies generate interventions that are less likely to scale.	• Emphasizing PA as a medium and manipulating the dynamic contexts that PA creates can confound explanatory designs. • Pragmatic designs better accommodate complex multicomponent interventions with potential to scale.
Versatility in Intervention Design & Aims	• Intervention designs focused on characteristics of PA (i.e., frequency, intensity, duration, mode, domain, type). • Aims limited to outcomes arising from PA per se, largely physical and mental health.	• Intervention designs focused on manipulating contextual factors in PA spaces (e.g., rules, dialogue, reinforcements, social interactions, etc.) • Aims broaden beyond innate benefits to include non-health outcomes of interest to important settings.
Practice Advantages during the Approach Phase
Alignment with Core Setting Goals	• Offers prospective community partners PA and health, regardless of their goals. • Reliant upon persuasion, relevant evidence, and ancillary transactions. • Preference diversity becomes a disincentive.	• Offers to help prospective community partners achieve their goals (improved health is a bonus). • Persuasion, relevant evidence, and ancillary transactions are secondary considerations. • Preference diversity is avoided but the power of diverse perspectives for problem solving remains.
Value Proposition	• Time and resource-intensive partnerships towards achieving ancillary health goals.	• Time and resource-intensive partnerships towards achieving core setting goals, plus health benefits.
Yield on Attempted Partnerships	• For each approach, the number of potential partners that agree to adopt or develop a PA intervention is limited. Partnerships are more likely among organizations already meeting their fundamental needs, who value health highly, and have resources to spare.	• For each approach, the number of potential partners that agree to adopt or develop a PA intervention remains limited but higher. Partnerships become more attainable in difficult circumstances because PA intervention becomes a means of achieving important non-health aims.
Practice Advantages during the Performance Phase
Community Partner Contribution and Engagement	• Interventions are more rigid, community partner input is limited to setting expertise (i.e., making the intervention work within organizational routines and practices). Limited sense of ownership.	• Interventions are more flexible; more room for input by community partners; partner input is expanded to setting and content expertise (i.e., making intervention achieve their outcomes within organizational routines and practices). Greater sense of ownership.
Effectiveness on Core Setting Goals	• Not intentionally pursued, therefore, less likely to be impactful on setting goals at a magnitude competitive with sedentary alternatives.	• Intentionally pursued, therefore, more likely to be impactful on setting goals at a magnitude competitive with sedentary alternatives, plus health benefits.
Assessment & Refinement	• Periodic assessment and refinement is based on PA and health; a difficult proposition for ancillary goals. • Less room for refinement, context is controlled.	• Periodic assessment and refinement based on setting goals; PA program is part of the broader assessment and refinement processes of the organization. • More room for refinement as context is manipulated.
Fit between Intervention and Setting	• Tension between achieving PA stimulus and accommodating setting routines and practices (e.g., stopping activities to exercise). • Fit is limited by limitations in community partner involvement in design and refinement.	• Contextual manipulations provide malleability to better fit with setting routines and practices (e.g., time exercising is also time spent pursuing primary goals). • Greater community partner involvement in design and refinement leads to better fit.
Long-Term Public Health Impact
Sustained Effectiveness on PA & Discontinuation	• Problems sustaining effectiveness on PA over time and discontinuation after cessation of research funding. This is due to lack of fit, lower effectiveness on core setting goals, and absence of continuous quality improvement.	• Improved sustained effectiveness on PA over time and reduced discontinuation after cessation of research funding. This is due to improved fit, improved impact on core setting goals, and consistent assessment and refinement.
Dissemination (active spread) & Diffusion (passive spread)	• Limitations in approach phase lead to lower yield of new partnership attempts, especially in historically excluded settings with non-health primary goals. Fewer partnerships makes for fewer opportunities to spread. • Core setting goals not impacted, less likely to be shared or viewed as competitive advantage	• Practice shifts during approach phase generate greater yield on attempted partnerships, especially in historically excluded settings with non-PA primary goals. More partnerships generate more opportunities for spread. • More likely to be shared across organizations and perceived as a competitive advantage when effective

Conceptual Shifts at Onset.

Embracing PA as medium enables us to broaden the forms that PA interventions can take and the aims that can be pursued. Previously neglected contextual features become available for systematic manipulation; and these can be harnessed to pursue aims that do not arise innately from PA [in its medicinal sense] at a level competitive with sedentary alternatives. Although from an explanatory design perspective (i.e., rigor) each contextual manipulation confounds our ability to detect relations between PA [as medicine] and health outcomes, from a pragmatic design perspective these sacrifices improve intervention relevance by providing greater flexibility in form and function (34). In our visual illustration of the S.P.A.C.E Hypothesis (Figure 1), pragmatic design decisions are placed adjacent to embracing PA as medium to reflect the synergy between these constructs and their indispensability for generating greater versatility in PA interventions. Pragmatic design decisions may include complex interventions, gold standard alternatives as comparison groups, and studies conducted in the intended settings with routine staff (34).

Practice Advantages during the Approach Phase.

In Figure 1, the “Approach Phase” encompasses interactions between the research team and a community organization that follow an initial “approach” by one of the partners to discuss potential collaborations. All academic-community partnerships begin with these initial interactions, but not all lead to partnerships. Our research has largely been conducted in African-American (26, 31, 33, 42–44) and Latino (32, 45–47) low-income communities where competing priorities and limited resources are ubiquitous. In our experience, establishing partnerships is more difficult where organizational leaders explicitly prioritize goals that seem outside the scope of what PA is perceived to intrinsically provide. Historically, PA intervention research has combined three strategies during the approach phase to establish partnerships—health persuasion, relevant evidence, and ancillary transactions—but at times achieved only limited success.

The first strategy, health persuasion refers to persuading settings to move health up their priority list, say from priority number six to priority number three (see Section II (Table 2)above for an example of this in schools). However, there is a limit to how high PA can go on the priority lists of settings with existing goals. Persuasion can also become contentious. The benefits of community engaged research arise from diverse perspectives brought to bear to solve problems. However, “preference diversity,” a potential pitfall, occurs when individuals within the same group want different outcomes, compete with each other for direction, and fail to achieve progress (48). Advocating for settings to put more of their finite time and resources toward PA and health at the expense of core setting goals (e.g., convincing schools to spend more time fighting obesity at the expense of academic instruction) can make researchers agents of preference diversity.

The second strategy, relevant evidence, refers to highlighting the benefits of PA on outcomes valued by potential community partners. In our own work we have sought to develop evidence relevant to important settings through tests of the effects of PA on cognition, academic performance, and psychosocial health in schools (30, 31, 33), and health and brain health in senior centers (32). Presenting relevant evidence strengthens partnerships because instead of encouraging potential partners to change their goals, it illustrates how PA will help them reach their goals. The school physical activity literature has excelled in this regard. For example, the Physical Activity Across the Curriculum (49) and InPACT (50) studies each demonstrated that embedding PA breaks into school curricula improved academic performance and boosted academic engagement. However, even presenting this evidence is often insufficient to initiate partnerships. When school principals or program directors plan activities, they do not compare PA interventions with placebos, wait-lists, no-intervention, or attention-control conditions. A school principal may value evidence that PA improves mathematics performance but still wonder: “Should I invest in exercise or math tutoring to improve math scores?” Hence, PA interventions compete with sedentary alternatives that may be more intuitively relevant, more satisfactory to stakeholders, and more empirically impactful on specific outcomes.

The final strategy, ancillary transactions, refers to discussions about exchanges of service between partners. Service has been a critical part of our academic-community partnerships. It is an effective way to strengthen ties, earn trust, establish personal relations, and contribute meaningfully to important causes we hold dear. For us, this has included service on advisory boards, panels, and committees; training staff; speaking at community events; consulting on evaluations and programming; and connecting partners with university resources. Similarly, there is mutual benefit to including setting staff as co-investigators on grant applications and co-authors on manuscripts. When external funding has been attained, we have sometimes funded programming and community partner staff time, offered settings to keep equipment and supplies so they may continue delivering interventions, and provided monetary compensation to settings and participants. However, ancillary transactions are not sufficient to justify intensive partnerships, and research grants end. Where settings have been primarily motivated by funding, staff, and services that rely on research grant dollars, the interventions have not sustained beyond the timeline of the funded study.

Ultimately, persuasion, relevant evidence, and ancillary transactions are of limited utility because they fail to align us with core setting goals (24). We can achieve greater success by shifting how we approach potential partners. Nearly a century ago, Dale Carnegie wrote:

Thousands of salespeople are pounding the pavements today, tired, discouraged and underpaid. Why? Because they are always thinking only of what they want. They don’t realize that neither you nor I want to buy anything. If we did, we would go out and buy it. But both of us are eternally interested in solving our (own) problems. And if salespeople can show us how their services or merchandise will help us solve our problems, they won’t need to sell us. We’ll buy (pp. 40–41) (51).

When PA intervention researchers attempt to form partnerships with settings that have goals outside of what innately arises from PA, we too often offer what we want, rather than what they want. Unmoored from a specific form and a narrow set of health-only outcomes, we can allow form to follow function. We can listen to our community partners, hear their goals, and embrace them as our own—it is no longer about what we are trying to do, it is about what they are trying to do. Importantly, this shifts the value proposition for settings as they evaluate the costs and benefits partnering with researchers or adopting EBIs. Instead of asking for substantial time and effort towards lower priority goals, we ask for substantial time and effort towards achieving their primary goals [plus health benefits]. The S.P.A.C.E Hypothesis proposes that embracing PA as medium allows us to align the goals of our PA programs with the core goals of important settings. This allows us to offer a stronger value proposition for potential partners. This improved value proposition generates a higher yield on attempted partnerships, especially in historically disadvantaged settings.

Practice Advantages during the Performance Phase.

In Figure 1, the “Performance Phase” begins after the academic-community partnership has been formalized and research has begun. This includes the phases of intervention development outlined in Table 1. The success of an academic-community partnership rests on how well it helps community partners achieve their goals in a way that fits their setting—in other words, how well the intervention “performs.” Here, embracing PA as medium confers three major practice advantages that enhance performance by improving the fit between interventions and settings. First, viewing PA as medium provides greater room for creativity, imagination, and interdisciplinary collaboration. This invites deeper participation from community partners because in order to develop [or adapt] a PA program with a non-health aim, partners must bring the expertise related to the non-health aim and what will fit their organizational routines and practices. This contrasts with conventional PA programs where the research team brings all of the content expertise to achieve the health aim, and the community partners contribute expertise to organizational setting routines and practices only. Deeper contribution and engagement by community partners should lead to better fit between intervention and setting (36).

Second, by harnessing PA as medium we expect greater impact on non-health goals compared to relying on the innate benefits of PA alone. This is for the simple reason that they are now being intentionally and systematically pursued. For example, daily aerobic exercise programs have been demonstrated to benefit math performance among children that are overweight or obese without any academic instruction [PA as medicine] (52), but the literature suggests that math gains are even larger when the physiological stimulus is combined with explicit math instruction, designed in partnership with a math instructor [PA as medicine + PA as medium] (49).

Third, the S.P.A.C.E Hypothesis proposes that interventions approaching PA as medium make continuous quality improvement more feasible. In their Dynamic Sustainability Framework, Chambers and Glasgow (2013) assert that the predictable lack of fit between interventions and settings over time underlies major implementation problems (23). They suggest a process of continual evaluation, cycling through assessment, feedback, and refinement towards increasingly greater effectiveness; rather than adhering closely to the intervention form that demonstrated initial effectiveness with the aim of maintaining the same impact. These ideas are powerful but require significant time and resources from community partners, seemingly without end. This lowers the value proposition for interventions that already require considerable cost and energy to establish. The S.P.A.C.E Hypothesis shifts the primary outcomes (driving continuous quality improvement) away from PA or health toward core setting goals, enabling partners to better justify ongoing assessment and refinement and roll it into existing evaluation processes. The S.P.A.C.E Hypothesis proposes that embracing PA as medium at the beginning allows interventionists to increase community partner engagement, better impact core setting goals, and iterate based upon those goals. These advantages are posited to improve fit between intervention and setting.

Long-Term Public Health Impact on Physical Activity.

The S.P.A.C.E Hypothesis proposes that where the aforementioned practice advantages are executed they will result in better performance on DI outcomes, and ultimately, higher public health impact on PA (operationalized as the product of intervention spread and intervention effectiveness). Embracing PA as medium allows greater partner engagement, intervention adaptability, intervention compatibility, and feasibility of continuous quality improvement. Each of these is an empirically demonstrated determinant of implementation (22), which is an important determinant of sustained effectiveness (23). There are situations in which focus on core setting goals—unrelated to health—may come at the expense of PA. However, impact on core setting goals may be an important reason that a setting continues to use a PA program, rather than adopting an alternative sedentary approach. When community partners see positive impacts on their core goals, view PA intervention activities as well aligned with routines and practices, and are actively engaged in continual refinement, interventions are more likely to sustained over time, and so too are their benefits (23, 24, 26).

With regard to spread, higher yield on initial contacts with community partners during the approach phase and better fit during the performance phase will lead to greater long-term dissemination (planned, systematic spread of ideas) and diffusion (unplanned, natural spread of ideas), as settings share their successes amongst one another. PA interventionists become present in new networks where they can target influential stakeholders, and competitors identify a competitive advantage and seek the same success (22, 35). One can imagine a future in which important settings visiting the web portals described in Table 2 see not only a menu of PA interventions demonstrated to improve PA and health outcomes in their setting (as is currently the case), but also a menu of PA interventions demonstrated to improve high value non-health goals [as well as or better than sedentary alternatives]. By way of example, The Community Guide could offer school principals a menu of PA interventions recommended for attendance, math performance, scientific literacy, conflict resolution, parent engagement, time-on-task, reading fluency and comprehension, and so on. What could this do for our low adoption rates? In the words of Carnegie, “The only way I get you to do anything is by giving you what you want. What do you want?” (emphasis added, p. 17) (51).

EXAMPLES OF INTERVENTIONS EMBRACING PHYSICAL ACTIVITY AS MEDIUM

Below we offer two examples of ongoing interventions embracing PA as medium from our own work. Each harnesses the contexts surrounding PA in different ways, but does so systematically, strategically, and with an eye towards dissemination.

Example #1 - Leaders @ Play.

Leaders @ Play was developed through a partnership between mental health services researchers, kinesiology researchers, and the Chicago Park District, in an effort to promote mental health in after-school settings serving children in marginalized communities characterized by high poverty and limited resources (43).

Approach Phase.

During an ongoing collaboration focused on primary school children (53), park supervisors expressed dismay at seeing teens who had been consistent attendees to park programming during elementary school get recruited by gangs in middle school. In response, university and park collaborators came together to imagine a system in which vulnerable youth would transition from Park Kids participants during elementary school, to volunteer Junior Counselors during middle school, and paid Recreation Leaders in high school. Hence, the research team aligned with a specific setting goal and the parties acquired funding to develop Leaders @ Play. The program was developed in partnership with staff at three parks, and designed to practice early job skills so that youth could succeed as Junior Counselors during summer camp. The specific skills identified—emotion regulation, effective communication, problem solving—were the result of input by community partners paired with a distillation of common elements across adolescent prevention programs. In this case, community partners identified the target outcomes—none of which arose innately from PA as a tool—and brought expertise with regard to the routines and practices of the setting; the research team brought expertise with regard to mental health promotion and PA.

Performance Phase.

The initial version of the program, entitled Leaders @ Play, was informed by a violence prevention curriculum and combined PA, small group discussions, role play, arts and crafts, mentorship, and multi-family group activities (44). Three parks and 46 youth participated. University staff with mental health expertise worked alongside park recreation leaders to deliver the program twice per week for 10-weeks. Assessments following the first iteration revealed that youth attendance—6.3 attendees per session—and park staff co-facilitation rate—51%—remained challenges. The partners then developed a second iteration of the program to improve fit with the park setting by increasing reliance on teachable moments during PA. Activities and strategies were developed and piloted at two parks in 2016, before further refinement and implementation at five parks (N=38 youth) in 2017 (42).

Leaders @ Play 2.0 sparked co-development of several physically active games, each designed to challenge early job skills. For example, The Amazing Race presents youth with a series of physical challenges to complete in small groups (e.g., 100 push-ups, 10 3-point baskets, 500 crunches, 20 pull-ups, 25 cartwheels). The first team to complete the challenge wins, and each team has two minutes to generate its strategy. This format provides ample challenges to communication, emotion regulation, and problem solving—all outcomes that are not innately impacted by PA as a tool. Games are bookended by pre- and post-game huddles. Pre-game huddles include brief introduction to rules and goals of the activity; post-game huddles are structured staff-led discussions focused on examples and opportunities to use job skills during and beyond the game. Sessions are co-facilitated by university staff and park recreation leaders who use sample scripts emphasizing lessons to be learned from each activity. In the second iteration, the recreation staff co-facilitation rate rose to 94% and teen attendance rose to 9.0 attendees per session (42). Staff also played a much more active role in the program, designing their own games and adapting the program to fit their routines.

Assessments of the second iteration revealed that youth engaged in the games with high levels of emotion, offering many opportunities to reinforce job skills. However, observations revealed the pre and post-huddles were difficult for staff and often failed to capitalize on the teachable moments that occurred during the PA activities. Specifically, staff were comfortable asking simplistic questions from the scripts (e.g., what went well and what did not), but found it difficult to elaborate or help youth reflect on particularly good or bad examples of communication, emotion regulation, or problem solving. It was even more challenging for staff to help youth think about generalizing skills to other settings and interactions. To this end, staff trainings and support were refocused to illustrate and practice how to Model, Observe, Reinforce, and Encourage (MORE) the desired skills during the activities and huddles. In Leaders @ Play, though youth are participating in PA, and enjoying the associated health benefits, the program’s focus was on reducing delinquency and facilitating teen employment, reflecting core goals of the program partners and communities served.

Leaders @ Play activities and strategies are available on-line at http://nafasipartners.fiu.edu, and efforts are ongoing to develop an online prototype to disseminate content to after school professionals. The Miami-Dade Parks, Recreation and Open Spaces Department has incorporated components of Leaders @ Play in their youth after-school program entitled Fit2Lead, begun in 2016 with funding by Miami Dade County as part of their initiatives around youth and community safety. To date, Fit2Lead has enrolled 501 at-risk youth ages 12–17 in 12 high-need areas of Miami (54). Results after 2-years suggest that youth arrests decreased significantly in neighborhoods implementing the program relative to those without the program (54, 55).

In Chicago, co-authors EEB, TGM, and SLF continue to plan the wider dissemination of Leaders @ Play with park district leadership, and major components including the Amazing Race, post-game huddles, and pathways to high school jobs have become staples of park programming. This reflects the reality that community partners generally exist in a world with a much faster pace and shorter timelines than researchers. Hence, they often wish to scale practices before they have gone through Phase III clinical trials. In the case of Leaders @ Play we offer our support in the implementation of the novel components and encourage partners to collect “residual” or “permanent product” data (naturally occurring opportunities for data collection that do not require extra effort). This does not preclude more rigorous scientific testing later and the experience and preliminary data can help to strengthen implementation during subsequent clinical trials. In this case, the adoption of components also reflects the partnership origins of the program, the relevance of the identified goals, and the fit of the adopted components with setting routines and practices (12).

Example #2 - Fraction Ball.

Fraction Ball was developed through a partnership between education researchers and primary school teachers, in an effort to promote rational number learning in a playful and physically active context.

Approach Phase.

The first installation of Fraction Ball arose from a partnership between El Sol Science and Arts Academy of Santa Ana California, and the University of California Irvine, STEM Learning Lab. The parties connected through the Playful Learning Landscapes initiative (46). The research team learned during several meetings with teachers that fractions and decimals were especially difficult for students. Teachers also reported that the school had recently laid down new blacktop for a basketball court but had not yet painted lines on the court. Thus, the group decided to develop a basketball game that reimagined the lines on a basketball court to emphasize fraction and decimal number learning; embracing a core goal of the school and utilizing existing resources.

Performance Phase.

The research team and teachers engaged in a series of iterative design sessions, and a few months after the idea was conceived Fraction Ball was painted on the school’s blacktop (see Figure 2). Figure 2a shows that the traditional 3-point arc is converted into a 1-point arc and smaller arcs closer to the basket represent 1/4, 1/2, and 3/4 point shots on one end of the court, and 1/3 and 2/3 point shots on the opposite end. The numbers are presented as fractions on the blue side of the court and as decimals on the green side, requiring students to convert between fractions and decimals. Figure 2b shows that, along the side of the court, a number line with both fraction and decimal representations helps students keep track of their score. Together, teachers and investigators developed structured games in which children rotate three roles—shooter, rebounder, and counter. During the games the shooter shoots, the rebounder calls out the value of the shot, and the counter moves down the number line that amount (see Figure 2c). Some games require children to score as many points as possible in a time limit, while others require them to achieve an exact number (e.g., 3.25) without over-shooting the goal. The physical nature of the games provides an environment characterized by high energy, motivation, engagement, and fun; children are incentivized to engage in arithmetic quickly and accurately. Hence, the school partner brought knowledge of the setting (the blacktop and games their students liked) and of the content (how to teach math) and the research team brought knowledge of embodied cognition, playful learning, and resources to help design the court.

Figure 2. Fraction Ball Pilot Installation.

(a) Fraction Ball court containing blue arches with decimals on the left side and green arches with fractions on the right side, numbers values increasing in fourths on near-side of court and in thirds on far side of the court; (b) teacher facilitating structured game with shooter, rebounder, and counter; (c) number line to assist children in keeping score.

The first evaluation study randomly assigned 5^th and 6^th grade students (N=69) to normal physical education (PE) or Fraction Ball for four 40-minute sessions, spread across four weeks. The Fraction Ball sessions were led by two math teachers who participated in a 90-minute training with the research team and were provided a 1-page script for each session. Results demonstrated that students assigned to Fraction Ball made significantly greater gains pretest to posttest on converting decimals to fractions, fractions to decimals, and a subset of items categorized as “near transfer” (e.g., basic fraction and decimal arithmetic) (45). Following acquisition of this preliminary data, adjustments were made to the activities to target additional math concepts and implement teacher feedback. A second evaluation study was undertaken with 4^th to 6^th grade students (N=160) randomized to PE or Fraction Ball for six 40-minute sessions across three weeks. Fraction Ball sessions were led by six math teachers who participated in a revised training and were provided with updated scripts. Results demonstrated significantly greater improvements from pre- to post-test in the Fraction Ball condition, on the composite score which is a sum of all test items including fraction and decimal arithmetic, conversion between fractions and decimals, and number line estimation.

Fraction Ball is a low-cost, scalable intervention that promotes embodied math learning in a fun and engaging approach in schoolyards and public parks. The partners have acquired a 5-year research contract to assess, refine, and scale the intervention across the Santa Ana Unified School District, which serves ~50,000 predominantly low-income Latino students. Through a genuine partnership with teachers and an intentional effort to align project and setting goals, Fraction Ball is embracing PA as medium to promote learning. The physical health, neurocognitive, and behavioral benefits of PA remain, but as secondary considerations behind achieving the setting’s primary goal of improving math performance.

CONCLUSION

PA intervention studies have demonstrated capacity to increase PA behavior among enrolled participants but have struggled to reach millions of individuals in need and to maintain effects once disseminated. The S.P.A.C.E Hypothesis contends that embracing PA as medium can improve long-term DI outcomes and public health impact by providing researchers greater versatility in intervention design and aims. We propose this versatility allows PA intervention researchers to align their program goals with the core goals of important settings, improving the yield on attempted academic-community partnerships [especially in low-income and racial/ethnic minority communities underrepresented in research] and improving fit where partnerships are established. These processes are hypothesized to improve DI outcomes and long-term public health impact. To illustrate the concept, we have provided examples from our own work that embraced PA as medium in different settings, with different populations, and from the perspective of different fields. The S.P.A.C.E Hypothesis calls for us to recognize and capitalize upon the versatility of our medium so that we may reach more people and have a greater impact on their health and wellness.

For a hypothesis to be scientific, it must be testable. The example interventions described in Section IV(Table 3) illustrate how we have harnessed PA as medium in our own work but their success or failure is not a test of the hypothesis. As a starting place, surveys distributed to settings that have already adopted scientifically-tested PA interventions could explore: (1) goal alignment (i.e., where are PA program goals on the list of organizational priorities); (2) performance phase determinants (i.e., to what extent did organizational staff contribute to intervention design, development, and adaptation; measures of perceived effectiveness; frequency of assessment and refinement; and staff perceptions of intervention fit, flexibility, and compatibility); and (3) DI outcomes (i.e., how many other organizations in their network adopted the intervention, how long it was implemented, and how long it sustained effectiveness on PA). Support for the S.P.A.C.E Hypothesis would be evidenced by associations between goal alignment (the independent variable), performance phase determinants (mediators), and DI outcomes (the dependent variable). Similarly, surveys administered to PA interventionists could reveal whether [and to what extent] they harness PA contexts to pursue non-health goals [PA as medium], align with setting goals, and achieve success on DI outcomes. Here, support for the S.P.A.C.E Hypothesis would be reflected by differences in DI outcomes (the dependent variable) by approach to PA (the independent variable); performance phase determinants would be tested for indirect or mediating effects depending on whether the data are cross-sectional or longitudinal.

Our purpose is to empower PA interventionists to achieve greater public health impact; hence, comparative effectiveness trials could definitively determine the validity of the hypothesis in each setting (e.g., schools, businesses, churches, hospitals). For example, in school settings, schools could be offered funding and resources to pair with PA interventionists to develop a PA intervention. The pairs could be given the same resources and supports to develop and evaluate the intervention with a focus on PA as medicine—emphasis on relationships between PA dose characteristics, health, and academic and neurodevelopmental benefits. The experimental manipulation would arise from the provision of additional training on how PA as medium can be leveraged to generate better DI outcomes (emphasis on contextual manipulations and performance phase advantages). With sufficient sample size and stratification on important factors (e.g., grade level, demographics, geographic region, interventionist experience) the randomization would yield comparable groups. Differences on DI outcomes (the dependent variable) over time could then be attributed to the differences in intervention approach at onset (PA as medium vs. PA as medicine).

KEY POINTS.

1. Physical activity researchers view physical activity as a form of medicine and have adopted a modified version of the translational continuum in medicine to create interventions. This has led to difficulties in dissemination and implementation, limiting public health impact.

2. Settings with broad reach (e.g., schools, workplaces, religious institutions) have primary goals that supersede physical activity and chronic disease, and few have time and resources to spare on ancillary goals.

3. The contexts that surround moving bodies are every bit as malleable and dynamic as those that surround sedentary bodies. Therefore, contexts surrounding physical activity can be strategically manipulated to achieve ends as diverse as those pursued while seated.

4. Recognizing and embracing physical activity as a medium puts interventionists in a better position to overcome challenges to dissemination and implementation by aligning with the core goals of important settings, improving the yield on attempted partnerships and improving the fit between interventions and settings where partnerships are established.