The following describes the research questions that were identified through a systematic review of population-based interventions designed to increase physical activity. These questions were published as part of the comprehensive evidence review conducted by the Task Force and published in a special supplement to the American Journal of Preventive Medicine (see Am J Prev Med 2002;22(4S), pp.73-106)

Public health practitioners, policy makers, employers/purchasers, and funders are encouraged to use these findings to help guide research priorities and build a broader evidence base.

RESEARCH ISSUES

Informational Approaches to Increasing Physical Activity

Effectiveness

The effectiveness of recommended and strongly recommended interventions in this section (i.e., community-wide campaigns and “point-of-decision” prompts) is established. However, important research issues regarding the effectiveness of these interventions remain.

Community-wide campaigns

• What characteristics and components of community-wide campaigns are most effective?
• How can community-wide efforts be institutionalized?
• What are the most effective and efficient delivery settings and channels (e.g., media, work settings)?
• Do coalitions enhance the delivery and effectiveness of interventions in community settings? If so, is the enhanced effect worth the potential added cost and burdens of implementation?

Point-of-decision prompts

• What is the sustained effect of placing signs near the elevator or escalator?
• What effect does varying the message or format of the sign have on providing a “booster” to stair climbing among the targeted population?
• What type of sign is most effective? What effect do format or size have, if any?
• Does effectiveness vary by setting and target audience?
• Is there a “critical distance” from the elevator or escalator to the stairs, in which the effect of signage on stair climbing behavior is reduced?

Because the effectiveness of mass media campaigns and classroom-based health education focused on information provision has not been established, basic research questions remain.

• Are these interventions effective in increasing physical activity?
• Do these interventions promote positive or negative attitudes toward physical activity?
• Do these interventions promote changes in physical activity mediators, such as stage of change or changes in policy, which may lead to population shifts?

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Behavioral and Social Approaches to Increasing Physical Activity

Effectiveness

The effectiveness of recommended and strongly recommended interventions in this section (i.e., school-based PE, social support interventions in community settings individually-adapted health behavior change programs) is established. However, research issues regarding the effectiveness of these interventions remain.

School-based PE

• Is school-based PE as effective for pre-school, elementary, and high school students as for middle school students?
• Is effectiveness of school-based PE different in co-ed classes versus single sex classes in junior high and high school?
• Are classroom teachers as effective as PE specialists?
• What is the relationship between PE class and overall daily physical activity? Is activity outside the school setting reduced when activity in PE is increased?
• Are before-school and after-school PE programs effective in increasing student's total daily activity levels or improving fitness?
• Does physical activity incorporated into regular classes result in effects similar to physical activity incorporated in a dedicated PE class?
• Is the effectiveness or efficacy of school-based PE affected by school setting (e.g., type of school, urban, suburban, etc.) or by population served (e.g., lower SES, racial or cultural differences)?

Social support interventions in community settings

• What type of social support and what medium works for whom? Do intensity and structure of the support make a difference?
• How does effect size vary by frequency of social interaction?
• Does the effect of these interventions vary by gender?

Individually-adapted health behavior change

• What characteristics and components are most effective?
• What mode of delivery is most effective?
• Does the effectiveness of behavioral change method vary by type of physical activity?

Because the effectiveness of college-based health education and PE, classroom-based health education focused on reducing television viewing and video game playing, and family-based social support has not been established, basic research questions remain.

• Are these interventions effective in increasing physical activity?
• Does these interventions promote positive or negative attitudes toward physical activity?

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Environmental and Policy Approaches to Increasing Physical Activity

Effectiveness

The effectiveness of the strongly recommended intervention in this section (i.e., creation of or enhanced access to places for physical activity) is established. However, research issues regarding the effectiveness of these interventions remain.

• What characteristics of a community are necessary for the optimal implementation of policy and environmental interventions?
• Does the effectiveness vary by type of access (e.g., work site facility or community facility) or socioeconomic group?
  • How can the necessary political and societal support for this type of intervention be created or increased?
  • Does creating or improving access motivate sedentary people to become more active, give those who are already active an increased opportunity to be active, or both?
  • If you build it, will they come? In other words, is enhanced access to places for activity sufficient to create higher physical activity levels, or are other intervention activities also necessary?
  • What are the effects of creating new places for physical activity versus enhancing existing facilities?
  • Which neighborhood features (e.g., sidewalks, parks, traffic flow, proximity to shopping) are most crucial in influencing activity patterns?
  • How does proximity of places such as trails or parks to residence affect ease and frequency of use?

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General Research Issues

Effectiveness

Several crosscutting research issues regarding the effectiveness of all of the reviewed interventions remain.

• What behavioral changes that do not involve physical activity can be shown to be associated with changes in physical activity? For example, does a decrease in time spent watching television mean an increase physical activity, or will another sedentary activity be substituted? Does an increase in the use of public transportation mean an increase in physical activity or will users drive to the transit stop?
• Physical activity is difficult to measure consistently across studies and populations. Although several good measures have been developed, several issues remain to be addressed.
• Reliable and valid measures are needed for the spectrum of physical activity.
  • Rationale: Current measures are better for vigorous activity than for moderate or light activity. Sedentary people are more likely to begin activity at a light level; this activity is often not captured by current measurement techniques.
• Increased consensus about “best measures” for physical activity would help to increase comparability between studies and would facilitate assessment of effectiveness.
  Note: This is not intended to preclude researchers' latitude in choosing what aspects of physical activity to measure and to decide which measures are most appropriate for a particular study population. Perhaps a useful middle ground position would be the establishment of selected core measures that most researchers should use which could then be supplemented by additional measures. The duration of an intervention's effect was often difficult to determine. Although some researchers did attempt long-term follow-up and assessment, many questions remain.
• How long does the effect of an intervention endure after intervention activities cease?
• Does the duration of an intervention affect the maintenance of activity? For example, does a two-year intervention show effectiveness for a longer period after the intervention ends than a ten-week intervention? What strategies can be used to maintain an intervention effect after the intervention ends? Are periodic “boosters” necessary or helpful?
• What is the nature and role of program “champions” in ensuring the successful implementation and adoption of an intervention?

Applicability

Each recommended and strongly recommended intervention should be applicable in most relevant target populations and settings assuming that appropriate attention is paid to tailoring. However, possible differences in the effectiveness of each intervention for specific subgroups of the population often could not be determined. Several questions regarding the applicability of these interventions in settings and populations other than those studies remain.

• Do significant differences exist regarding the effectiveness of these interventions, based on the level or scale of an intervention?
• What are the effects of each intervention in various socio-demographic subgroups, such as age, gender, race, or ethnicity?

Other positive or negative effects

The studies included in this review did not report on other positive and negative effects of these interventions. Research on the following questions would be useful:

• Do informational approaches to increasing physical activity help to increase health knowledge? Is it necessary to increase knowledge or improve attitudes toward physical activity to increase physical activity levels?
• Do these approaches to increasing physical activity increase awareness of opportunities for and benefits of physical activity?
• What are the most effective ways to maintain physical activity levels after the initial behavior change has occurred?
• Are there other benefits from an intervention that might enhance its acceptability? For example, does increasing social support for physical activity carry over into an overall greater sense of community?
• Are there any key harms?
• Is anything known about whether or how approaches to physical activity could reduce potential harms (e.g., injuries or other problems associated with doing too much too fast)?

Economic evaluations

The available economic data were limited. Therefore, considerable research is warranted on the following questions.

• What is the cost effectiveness of each of these interventions?
• How can effectiveness in terms of health outcomes or quality adjusted health outcomes be better measured, estimated, or modeled?
• How can the cost benefit of these programs be estimated?
• How do specific characteristics of each of these approaches contribute to economic efficiency?
• What combinations of components in multi-component interventions are most cost-effective?

Barriers

Research questions generated in this review include the following:

• What are the physical or structural (environmental) barriers to implementing these interventions?
• What resource (time and money) constraints prevent or hinder the implementation of these interventions?

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