The predictors of short- and long-term physical activity levels of older adults from FABS (Fitness for the Ageing Brain Study)

Abstract

Background: Physical activity (PA) may potentially delay or slow down cognitive decline. Developing strategies to encourage the adoption and long-term maintenance of PA is a major challenge. Knowing what factors predict an increase in PA will enhance and focus such strategies. We aimed to identify the baseline characteristics of FABS participants that predict short and long-term PA. Methods: Volunteers with memory complaints but dementia-free recruited from memory clinics and the general community were randomly assigned to a control or PA group. The PA group undertook an individualised home-based PA program with a target of 150 minutes/week of moderate PA and a behavioural intervention for the first 6-months. They then continued their PA for a further 12 months without any further intervention. The control group continued their usual PA throughout the study. Baseline measures included; age; gender; Body Mass Index (BMI); PA (7-day pedometer scores); PA self-efficacy(self-efficacy to be active in adverse events); cognition (Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale - cognitive section (ADAS-cog)) and physical and mental health (SF-36V2, components PCS and MCS).These were repeated at 6, 12 and 18 months. Mixed-effects longitudinal regression models were used to determine predictors of PA. Results: One hundred and seventy participants mean age 68.5 (SD 8.6) years started the study. At each time-point there was no significant difference between groups in the number of participants who were retained in the study. After 6 and 12 months the PA group had significantly higher PA than the control group (P<0.01). When all study participants were considered higher self-efficacy (P<0.001); cognition (MMSE) (P<0.01) and physical health (PCS) (P<0.01) were significant independent predictors of higher PA at all time-points. Older age (P<0.001) and having a higher BMI (P<0.01) predicted lower PA. Conclusion: In this group of older adults having better perceived physical health, higher PA, self-efficacy and cognition resulted in higher PA levels in the short and long-term. Future programs should aim to maximise and maintain these characteristics and provide physical activities that accommodate ageing and minimise the potential limitations of higher BMI on physical activity.