Identifying subgroups that succeed or fail with three levels of physical activity intervention: the Activity Counseling Trial.

The authors used recursive partitioning methods to identify combinations of baseline characteristics that predict 2-year physical activity success in each of 3 physical activity interventions delivered in the multisite Activity Counseling Trial. The sample consisted of 874 initially sedentary primary care patients, ages 35-75 years, who were at risk for cardiovascular disease. Predictors of 2-year success were specific to each intervention and represented a range of domains, including physiological, demographic, psychosocial, health-related, and environmental variables. The results indicate how specific patient subgroups (e.g., obese, unfit individuals; high-income individuals in stable health) may respond differently to varying levels and amounts of professional assistance and support. The methods used provide a practical first step toward identifying clinically meaningful patient subgroups for further systematic investigation.     

Longitudinal measurement invariance of psychosocial measures in physical activity research: an application to adolescent data

The current study served as a practical and substantive guide to establishing longitudinal measurement invariance of psychosocial measures commonly used in adolescent physical activity (PA) research. Psychosocial data on an initial sample of 878 adolescents (ages 11–15) recruited through primary care providers were provided at baseline, 6, 12, and 24 months. The target measures included family support, peer support, decisional balance (pros, cons), self‐efficacy, and behavioral strategies. Five of the six psychosocial measures exhibited strict longitudinal measurement invariance, with the sixth measure (self‐efficacy) exhibiting strong longitudinal measurement invariance. These findings support the equivalence of these measures across time, and provide the foundation to substantively interpret group differences and associations involving these measures and PA.     

Process Evaluation of A Physical Activity Self-Management Program For Children: Spark

Abstract

SPARK is a controlled field study of a multi-component elementary school program to promote physical activity. One component is a weekly classroom-based self-management program, with the goal of increasing physical activity outside of school. The curriculum included goal setting, behavioral skills training, a reward system, and parent involvement. An evaluation of curriculum implementation and association between process and outcome was conducted using direct observation of lessons, subjective ratings by 24 teachers and 391 parents, and participation records of 549 students. Teachers viewed the self-management curriculum less positively than the physical education curriculum. Teachers were observed implementing an average of 65% of curriculum elements, which may have contributed to the limited effects of the self-management program. Student participation in the program, measured by points earned for doing out of school physical activity, was correlated significantly with changes in body mass index and multiple psychosocial variables among boys but not girls. Barriers to full program implementation were identified, and a remaining challenge is to improve self-management curriculum implementation by teachers.     

Behavioral control of exercise in adults: Studies 7 and 8

Abstract

Building on our previous six study series, the current studies 7 and 8 evaluated behavioral methods of improving adherence to exercise in adults. The studies tested the effectiveness of a single exercise modality versus choice of a variety of exercises and were conducted as part of a 12-week extended studies college course in San Diego, CA. Recruitment efforts were targeted to individuals who reported that they were sedentary and/or had experienced difficulty adhering to regular exercise. Participants were 42 adults (32F, 10M; mean age = 42.0) in Study 7 and 48 adults (35F, 8M; mean age = 47.9) in Study 8. In each study, subjects were randomly assigned to a single focus or variety exercise condition. There were no significant group differences in class attendance or out-of-class exercise adherence rates in Studies 7 or 8. In Study 7, significantly lower drop-out rates were detected in the single focus group (19%) than the variety condition (47.6%) (p = 0.04). No significant group differences were detected for drop-out rates in Study 8. Suggestions for further research are offered.     

A randomized controlled trial of single versus multiple health behavior change: promoting physical activity and nutrition among adolescents.

Targeting multiple behaviors for change may provide significant health benefits. This study compared interventions targeting physical activity and nutrition (PAN) concurrently versus physical activity (PA) alone. Adolescents (N=138) were randomized to the PAN or PA intervention or control condition (n=46 per group). Primary outcomes were change in PA accelerometer and 3-day dietary recording from baseline to 3-month follow-up. The PAN and PA interventions were efficacious in supporting boys' (p<.001) but not girls' (p=.663) PA relative to the control condition. Dietary change was minimal. Although the findings do not reveal a decrement to PA promotion when a nutrition intervention was added, neither do they reveal any additional benefit. More studies comparing single versus multibehavioral interventions are needed.