Effects of Physical Activity, Diet, & Self-Efficacy on Physical Function in Older Adults

Abstract

Background: Many older adults (OA) demonstrate decreased physical function (PF) which may lead to disability. Increased physical activity (PA), eating a healthful diet, and maintaining higher self-efficacy (SE) each improve PF in older adults, but few studies have examined if the combination of these three variables have an additive effect on PF. Additionally, few longitudinal studies have assessed the change in PF in relation to the changes in PA, diet, and SE. Purpose: The purpose of this study was to determine: (a) the relationship between PF and PA levels, fruit and vegetable intake (F&V), and exercise SE; (b) the percentage of variance in PF that is explained by PA levels, F&V intake, and exercise SE; and (c) if changes in PA levels, F&V intake, and exercise SE are related to changes in PF in community-dwelling OA. Methods: A secondary data analysis was conducted using data from the SENIOR II project. The participants (N=470) were community-dwelling OA (M=79.9, SD=5.8). PF was measured using the Timed Up and Go. F&V intake, PA and exercise SE were measured using the NCI Fruit and Vegetable Screener, the Yale Physical Activity Survey, and the Exercise Self-Efficacy Scale, respectively. Results: Pearson’s r correlation showed that PF was significantly related to PA (r=-.207, p<.001), F&V (r=-.125, p<.001), and SE (r=-.120, p<.01). Multiple regression analysis revealed that PA, F&V, and SE explained almost 15% of the variation of PF in OA. A repeated measures MANCOVA revealed that vigorous PA levels increased in individuals whose PF improved from baseline to 48-months. Conclusion: PA, F&V, and SE combined had an additive effect on PF in OA and explained a greater variance in PF than each individual variable. Declines in PA, F&V, and SE did not result in significant declines in PF in OA; however, results indicate that variable levels at a younger age may be related to PF in OA.