Predictors of physical activity at 12 month follow-up after a supervised exercise intervention in postmenopausal women.
BACKGROUND
Few studies have examined recreational physical activity (RPA) after participating in a structured exercise intervention. More specifically, little is known about the long-term effects of exercise interventions in post-menopausal women. This study had two objectives: 1) To compare RPA in postmenopausal women in the exercise group and the control group 12 months after the end of the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) Trial; and 2) To apply the Theory of Planned Behaviour (TPB) to identify predictors of RPA 12 months post-intervention among women in the exercise group.


METHODS
Self-reported RPA 12-months post-intervention from a validated questionnaire was used to estimate RPA levels for control group (118/160, 74% response) and exercise group participants (126/160, 79% response). Bivariate analysis was used to compare RPA between exercise and control group participants and to identify TPB variables for multivariate analysis. Logistic regression was applied to TPB data collected from self- administered questionnaires at end of trial by exercise group participants (126/160, 79% response) to identify predictors of long-term RPA.


RESULTS
At 12 months post-intervention, 62% of women in the exercise group were active compared to 58% of controls (p = 0.52). Of the TPB constructs examined, self-efficacy (OR =2.98 (1.08-8.20)) and behavioural beliefs (OR = 1.46 (1.03-2.06)) were identified as predictors of RPA for exercise group participants.


CONCLUSIONS
Levels of RPA in the exercise and control groups were comparable 12 months post intervention, indicating that participation in the ALPHA trial was associated with increased physical activity in previously inactive women, regardless of randomization into either the exercise group or in the control group. Exercise interventions that promote self-efficacy and positive behavioural beliefs have the potential to have long-term impacts on physical activity behaviour, although further research is needed to examine additional psychological, social and environmental predictors of long-term RPA in post-menopausal women.


BACKGROUND
ClinicalTrials.gov NCT00522262.
Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3rd Floor, TRW Building, 3280 Hospital Drive NW Calgary, Alberta, T2N 4Z6, Canada. feaparic@ucalgary.ca.
Fabiola E
FE
Aparicio-Ting
Department of Cancer Epidemiology and Prevention Research, Cancer Control Alberta, Alberta Health Services, Holy Cross Centre, 2210-2nd Street SW, Calgary, Alberta, T2S 3C3, Canada. Megan.Farris@albertahealthservices.ca.
Megan
M
Farris
Faculty of Physical Education and Recreation, University of Alberta, W1-34 Van Vliet Centre, University of Alberta, Edmonton, Alberta, T6G 2H9, Canada. kerry.courneya@ualberta.ca.
Kerry S
KS
Courneya
O'Brien Centre for the Bachelor of Health Sciences, Cumming School of Medicine, University of Calgary, 3300 Hospital Drive NW Calgary, Alberta, T2N 4N1, Canada. arschiller@gmail.com.
Ashley
A
Schiller
Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3rd Floor, TRW Building, 3280 Hospital Drive NW Calgary, Alberta, T2N 4Z6, Canada. Christine.Friedenreich@albertahealthservices.ca.|Department of Cancer Epidemiology and Prevention Research, Cancer Control Alberta, Alberta Health Services, Holy Cross Centre, 2210-2nd Street SW, Calgary, Alberta, T2S 3C3, Canada. Christine.Friedenreich@albertahealthservices.ca.|Department of Oncology, Cumming School of Medicine, University of Calgary, Tom Baker Cancer Centre, 1331 29th Street NW, Calgary, Alberta, T2N 4N2, Canada. Christine.Friedenreich@albertahealthservices.ca.
Christine M
CM
Friedenreich
D001943:Breast Neoplasms / Q000517:prevention & control*; D015444:Exercise / Q000523:psychology*; D005081:Exercise Therapy / Q000379:methods* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D017698:Postmenopause / Q000502:physiology / Q000523:psychology; D011897:Random Allocation; D020377:Self Efficacy; D011795:Surveys and Questionnaires / Q000592:standards; D016896:Treatment Outcome; D014930:Women / Q000193:education / Q000523:psychology*