Advancing Physical Activity Theory: A Review and Future Directions

Exploring changes in physical activity, sedentary behaviors and hypothesized mediators in the NEAT girls group randomized controlled trial

OBJECTIVE

To evaluate the impact of a 12-month school-based multi-component program on adolescent girls' physical activity and sedentary behaviors, and hypothesized mediators of physical activity behavior change.

DESIGN

Group randomized controlled trial with 12-month follow-up.

METHODS

The intervention, guided by Social Cognitive Theory, involved 357 adolescent girls (13.2 ± 0.5 years) from 12 secondary schools (6 intervention schools, 6 control schools) in low-income communities in the Hunter and Central Coast regions of New South Wales, Australia. The intervention included enhanced school sport, lunchtime physical activity sessions, interactive seminars, student handbooks, nutrition workshops, pedometers, parent newsletters and text messages to encourage physical activity and healthy eating, and a decrease in sedentary behavior. Outcomes were assessed at baseline and 12-months and included: physical activity (accelerometers), sedentary behaviors (questionnaire and accelerometers), and social-cognitive mediators of physical activity (questionnaire).

RESULTS

There were significant between group differences in favor of the intervention group for self-reported recreational computer use (-26.0 min; 95% CI, -46.9 to -5.1), and sedentary activities summed (-56.4 min; 95% CI, -110.1 to -2.7), however objective sedentary behavior showed no differences. There were no group-by-time effects for any of the physical activity outcomes or hypothesized mediators.

CONCLUSIONS

A school-based intervention tailored for adolescent girls from schools located in low-income communities significantly reduced time spent in sedentary activities. However, improvements in physical activity and hypothesized mediators of physical activity behavior were not observed. Future studies are encouraged to explore alternative mechanisms of behavior change derived from integrated and socio-ecological theories.

Perceived stress, behavior, and body mass index among adults participating in a worksite obesity prevention program, Seattle, 2005-2007

Introduction

Stress in numerous contexts may affect the risk for obesity through biobehavioral processes. Acute stress has been associated with diet and physical activity in some studies; the relationship between everyday stress and such behavior is not clear. The objective of this study was to examine associations between perceived stress, dietary behavior, physical activity, eating awareness, self-efficacy, and body mass index (BMI) among healthy working adults. Secondary objectives were to explore whether eating awareness modified the relationship between perceived stress and dietary behavior and perceived stress and BMI.

Methods

Promoting Activity and Changes in Eating (PACE) was a group-randomized worksite intervention to prevent weight gain in the Seattle metropolitan area from 2005 through 2007. A subset of 621 participants at 33 worksites provided complete information on perceived stress at baseline. Linear mixed models evaluated cross-sectional associations.

Results

The mean (standard deviation [SD]) Perceived Stress Scale-10 score among all participants was 12.7 (6.4), and the mean (SD) BMI was 29.2 kg/m² (6.3 kg/m²). Higher levels of perceived stress were associated with lower levels of eating awareness, physical activity, and walking. Among participants who had low levels of eating awareness, higher levels of perceived stress were associated with fewer servings of fruit and vegetables and greater consumption of fast food meals.

Conclusion

Dietary and physical activity behaviors of workers may be associated with average levels of perceived stress. Longitudinal studies are needed, however, to support inclusion of stress management or mindfulness techniques in workplace obesity prevention efforts.

Correlates of physical activity in a population-based sample of kidney cancer survivors: an application of the theory of planned behavior

Background

Over half of kidney cancer survivors (KCS) are completely inactive and only a quarter are meeting physical activity (PA) guidelines. This highlights the need to identify and understand the determinants of PA in this understudied population. The purpose of this study is to determine the social cognitive correlates of PA intention and behavior in KCS using the Theory of Planned Behavior (TPB).

Methods

All 1,985 KCS diagnosed between 1996 and 2010 in Alberta, Canada were mailed a self-report survey that consisted of the Godin Leisure Time Exercise Questionnaire and standard TPB items for intention, planning, perceived behavioral control (PBC), affective and instrumental attitudes, and descriptive and injunctive norms. Standard demographic and medical variables were also collected.

Results

Completed surveys were received from 703 of 1,654 (43%) eligible KCS. The TPB was tested using structural equation modelling and demonstrated an adequate-to-good fit to the data [χ² = 256.88, p < .001; TLI = 0.97; CFI = 0.98; RMSEA = 0.06, 90% CI = 0.05-0.06].

There were significant pathways to PA from PBC (ß = 0.18, p = 0.02), planning (ß = 0.22, p < 0.01), and intention (ß = 0.31, p < 0.01); and to planning from intention (ß = 0.81, p < 0.01). In addition, there were significant model pathways to intention from instrumental attitude (ß = 0.28, p = 0.03), descriptive norm (ß = 0.09, p = 0.01), and PBC (ß = 0.52, p < 0.01). Overall, the TPB accounted for 69%, 63%, and 42% of the variance in intention, planning and PA, respectively.

Conclusion

The TPB appears to be a useful model for explaining PA in KCS. All TPB constructs except injunctive norm and affective attitude were useful for explaining intention with PBC emerging as the largest correlate. Developing PA interventions based on the TPB may be effective in promoting PA in KCS and may lead to important improvements in health.