Physical Activity InterventionsMediating variable framework in physical activity interventions: How are we doing? how might we do better?
Section snippets
Intervention → behavior: how are we doing?
Table 1 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 presents a summary of 23 physical activity intervention studies. While attempting to increase physical activity is highly laudable, we need to critically assess how well we have done. These critical comments apply to our own work, as well as that of others, and the results are comparable to those found with other behaviors.35
The primary purpose of intervention
Mediating variable framework
Similar to a recent paper by Hansen and McNeal,36 this paper argues that: (1) interventions work by means of mediating variables; (2) current theoretical models from which mediating variables are obtained often do not account for substantial variability in the targeted outcomes; (3) interventions have not been shown to effect substantial change in the mediating variables; and, together, (4) these factors impose limits on the effectiveness of the interventions. As a result, priority should be
Mediating variables → behavior: what’s possible?
Within the mediating variable framework, the maximum possible relationship of mediating variables to behavior places a limit on the effect of an intervention on behavior. A review of the theoretical literature enables us to assess what the current maximum level of predictiveness might be. There have been several recent reviews of theoretical models predicting physical activity.40, 41, 42 Table 2 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67,
Interventions → mediating variables: are we changing what we need to change?
If we accept that interventions work through mediating variables, then the extent to which interventions have an impact on mediating variables places another limit on the extent to which an intervention can have an impact on behavior. Few of the research projects summarized in Table 1 measured mediating variables. The ones that did, tested either an effect of the intervention on the mediating variables15 or the relationships of change in the mediating variable to change in physical activity
Discussion
This brief review suggests two major reasons why interventions are not attaining desired levels of change in behavioral outcomes. First, current theories do not predict behavior or behavior change at high enough levels. Second, interventions are not substantially effecting change in the mediating variables.
The low predictiveness of theory for behavior (RM→B2) specifies the vital importance of theory in the behavior change process. Clearly, more basic behavioral and social science research on
Recommendations for research
To facilitate communication, behavioral and social science research (BSSR) can be grouped into theoretical, basic, mediator change, and interventional categories. Theoretical BSSR includes research on basic mechanisms of cognition, emotion, and behavior not ordinarily focused on the behaviors of interest to us (e.g., physical activity). Basic BSSR employs the concepts, methods, and measures of theoretical BSSR to understand the behavior(s) of interest. Mediator Change research tests methods for
Acknowledgements
The authors were funded during the writing of this paper by grants from NIH: CA61596. The authors appreciate the comments of many reviewers, including Len Epstein, Rod Dishman, and Bess Marcus.
References (95)
- et al.
A multisite field test of the acceptability of physical activity counseling in primary careproject PACE
Am J Prev Med
(1996) - et al.
Mediators of change in physical activity following an intervention in primary carePACE
Prev Med
(1997) - et al.
Training Physicians to conduct physical activity counseling
Prev Med
(1997) - et al.
Reduction in cardiovascular disease risk factorSixth-month results from Project Active
Prev Med
(1997) - et al.
Enhancing exercise adherance in middle-aged males and females
Prev Med
(1994) - et al.
Changes in health behaviors of older adultsThe San Diego Medicare Preventive Health Project
Prev Med
(1994) - et al.
School physical educationeffect of the child and adolescent trial for cardiovascular health
Prev Med
(1996) - et al.
The effects of the child and adolescent trial for cardiovascular health upon psychosocial determinants on diet and physical activity behavior
Prev Med
(1996) - et al.
Strategies for increasing early adherence to and long term maintenance of home-based exercise training in healthy middle aged men and women
Am J Cardiol
(1988) - et al.
Training effects of long versus short bouts of exercise in healthy subjects
Am J Cardiol
(1990)
A multivariate study of determinants of vigorous exercise in a community sample
Prev Med
Identifying correlates of walking for exercisean epidemiologic prerequisite for physical activity promotion
Prev Med
Explanation of vigorous physical activity during two years using social learning variables
Soc Sci Med
The relative influence of health beliefs, parental and peer behaviors and exercise program participation on smoking, alcohol use and physical activity
Soc Sci Med
A prospective study of the determinants of physical activity in rural fifth-grade children
Prev Med
Sociocultural correlates of childhood sporting activitiestheir implications for heart health
Soc Sci Med
Psychosocial predictors of physical activity in adolescents
Prev Med
Determinants of exercise in children
Prev Med
Correlates of vigorous exercise in a predominantly low SES and minority high school population
Prev Med
Theory as mediating variableswhy aren’t community interventions working as desired?
Ann Epidemiol
Efficacy and effectiveness trials (and other phases of research) in the development of health promotion programs
Prev Med
Walking to meet health guidelinesThe effect of prompting frequency and prompt structure
HealthPsychol
A controlled trial of physician counseling to promote the adoption of physical activity
Prev Med
Community education for cardiovascular disease preventionRisk factor changes in the Minnesota Heart Health Program
Am J Public Health
Effect of community health education on physical activity knowledge, attitudes, and behavior
Am J Epidemiol
Cardiovascular disease risk reduction for tenth gradersa multiple-factor school-based approach
JAMA
Promoting children’s diet and physical activity among childrenresults of a school-based intervention study
Am J Public Health
School promotion of healthful diet and physical activityimpact on learning outcomes and self-reported behavior
Health Educ Q
Community wide youth exercise promotionlong-term outcomes of the Minnesota Heart Health Program and the Class of 1989 Study
J Sch Health
Effects of a curriculum and inservice program on the quality of elementary physical education classes
Res Q Exerc Sport
The effects of a 2-year physical education program (SPARK) on physical activity and fitness in elementary school students
Am J Public Health
Outcomes of a field trial to improve children’s dietary patterns and physical activity. The Child and Adolescent Trial for Cardiovascular Health (CATCH)
JAMA
Operational design and quality control in the CATCH Multicenter Trial
Prev Med
Results of the Teach Well Worksite Wellness Program
Am J Public Health
Long-term effects of varying intensities and formats of physical activity on participation rates, fitness, and lipoproteins in men and women aged 50 to 64 years
Circulation
Group- vs. home-based exercise training in healthy older men and womenA Community-Based Clinical Trial
JAMA
Predicting long-term adherence to aerobic exercisea comparison of two models
J Sport Exerc Psychol
Effects of a 6-month incentive-based exercise program on adherence and work capacity
Med Sci Sports Exerc
Low cost strategies for increasing excercis behaviorrelapse preparation training and social support
Behav Modif
Evaluation of relapse prevention and reinforcement interventions to promote exercise adherence in sedentary females
Res Q Exerc Sport
Prescribing exercise in multiple short bouts versus on continuous bouteffects on adherence, cardiorespiratory fitness, and weight loss in overweight women
Int J Obes
Effect of a stimulus control intervention on attendance at a university fitness center
Behav Modif
Preventing cardiovascular disease through community based risk reductionThe Bootheel Heart Health Program
Am J Public Health
Theory as mediating variableswhy aren’t community interventions working as desired?
Ann Epidemiol
The law of maximum expected potential effectconstraints placed on program effectiveness by mediator relationships
Health Educ Res Theory Pract
Cited by (715)
Review of gender, socioeconomic status, and ethnic background considerations reported in active school travel intervention studies
2021, Journal of Transport and HealthThe Use of Theory to Develop Physical Activity Interventions in Urological Cancer Survivors: A Narrative Review
2021, Seminars in Oncology NursingEffects of active video games on physical activity among overweight and obese college students: a systematic review
2024, Frontiers in Public HealthCost-Effectiveness of Prolonged Physical Activity on Prescription in Previously Non-Complying Patients: Impact of Physical Activity Mediators
2023, International Journal of Environmental Research and Public Health