Browsing by Author "Williams, David Michael"

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    Multi-Phase Mediator Analysis of a Social Cognitive Church-Based Physical Activity Intervention
    Williams, David Michael (Virginia Tech, 2004-05-05)
    This study tested an integrated social cognitive model of physical activity intention formation, onset, and maintenance among sedentary participants (N = 465) in a church-based, social cognitive, physical activity intervention. Three separate models were tested via structural equation modeling. Each model provided a good fit to the data. The models explained 28%, 19%, and 9% of the variance in intention formation, physical activity onset, and physical activity maintenance, respectively. Consistent with hypotheses, self-efficacy mediated the effect of positive outcome expectancy on behavioral intention, adoption of behavioral strategies mediated the effect of the intervention on physical activity onset, and maintenance of self-efficacy mediated the effect of the intervention on physical activity maintenance. Contrary to hypotheses, change in self-efficacy from baseline to post-assessment and perceived satisfaction with intervention outcomes did not have effects on physical activity onset or maintenance. The findings provide preliminary evidence that physical activity intention formation, onset, and maintenance are distinct processes driven by different determinants before, during, and following a social cognitive physical activity intervention.
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    A Social Cognitive Model of Creatine Use Among Male, Recreational Weight-Lifters
    Williams, David Michael (Virginia Tech, 2000-12-15)
    This study investigated social cognitive determinants of creatine supplementation among 171 male, undergraduate, recreational weight-lifters. Participants responded to a packet of questionnaires that assessed their history and rate of creatine use, self-efficacy for improving their workout performance with and without creatine, and expected outcomes of improved workout performance and creatine use, as well as several other demographic variables. Fifty percent of the sample reported past creatine use. The data was used to establish the internal consistency, test-retest reliability and predictive validity of factor-based scales for valued outcome expectancies and disincentives for creatine use scales. A social cognitive model was shown to predict past creatine use (R² = .372). The results lay the groundwork for further examination of the determinants of creatine supplementation and the use of other controversial and potentially harmful performance-enhancing dietary supplements.