Increasing Physical Activity

Research Gaps

What are Research Gaps?

Prior to and during the literature review and data analysis, the review team and the Community Preventive Services Task Force attempt to address the key questions of what interventions work, for whom, under what conditions, and at what cost. Lack of sufficient information often leaves one or more of these questions unanswered. The Community Guide refers to these as "research gaps." Research gaps can be pulled together in the form of a basic set of questions to inform a research agenda for those in the field.

Identified Research Gaps

Results from the Community Guide reviews of physical activity interventions indicate that a number of these interventions are effective in increasing physical activity across a range of settings. However, questions remain regarding more specific characteristics of how the intervention is implemented, with whom, and where. Research gaps are provided for the following categories:

Campaigns and informational approaches

Behavioral and social approaches

Environmental and policy approaches

General research issues

 

Campaigns and Informational Approaches

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 effect does varying the message or format of the prompt have on providing a “booster” to stair use among the targeted population?
• What type of prompt is most effective? What effect does format or size have, if any?
• Is there a "critical distance" from the elevator or escalator to the stairs, in which the effect of signage on stair use is reduced?
• Are there a minimum or maximum number of flights one must expect stair users to ascend in order for the prompt to be effective?
• How many individuals read the point-of-decision prompt and react (i.e., increase their use of the stairs) as a result, as opposed to reacting to other knowledge that the intervention is occurring?
• What strategies can be used to maintain the intervention effect after the intervention ends? Are periodic “boosters” necessary or helpful?

Behavioral Approaches

School-based physical education (PE)

• Is school-based PE as effective for preschool, elementary, and high school students as for middle school students?
• Is effectiveness of school-based PE different in coed 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 socioeconomic status, 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?
• Are these interventions effective in increasing physical activity?
• Do these interventions promote positive or negative attitudes toward physical activity?
• Basic research questions remain because the effectiveness has not been established for the following:
  • College-based health education and PE
  • Classroom-based health education focused on reducing television viewing and video game playing
  • Family-based social support

Environmental and Policy Approaches

• 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., worksite 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 the most crucial in influencing activity patterns?
• How does proximity of places such as trails or parks to residence affect ease and frequency

General Research Issues

Effectiveness. Several crosscutting research issues about 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 in 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.

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 about the applicability of these interventions in settings and populations other than those studied remain.

• Are there significant differences in the effectiveness of these interventions, based on the level or scale of an intervention?
• What are the effects of each intervention in various sociodemographic 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 multicomponent 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?

Evidence Reviews

Kahn EB, Ramsey LT, Brownson R, et al. The effectiveness of interventions to increase physical activity: a systematic review. [PDF - 3.14MB] Am J Prev Med 2002;22(4S):73-107.

Soler RE, Leeks KD, Ramsey Buchanan L, et al. Point-of-decision prompts to increase stair use: a systematic review update. [PDF - 1.59MB] Am J Prev Med 2010;38(2S):292-300.