A Theory of Physical Activity Maintenance

Regular physical activity is related to numerous psychological and physical benefits. Physical activity interventions have had varying degrees of success with adoption; however, maintenance over the long term is even more difficult to achieve, as the majority of individuals who start a physical activity program drop out or relapse. Although the physical activity maintenance literature is scant, there is evidence that the predictors of adoption are different from those of maintenance. Thus, it follows that physical activity adoption and maintenance require unique approaches. The explanatory power of such predictors, however, is limited by the absence of a cogent theoretical framework. Therefore, this paper presents the Physical Activity Maintenance (PAM) theory, which incorporates individual psychosocial variables (goal-setting, motivation, and self-efficacy), and contextual variables of the environment and life stress (triggers of relapse). Goal-setting is framed as satisfaction, attainment, and commitment; motivation as self-motivation and expectations; and self-efficacy as both barrier and relapse. The contextual variables may facilitate or impede physical activity maintenance directly and indirectly via the individual psychosocial variables. The PAM is presented to stimulate research on physical activity maintenance and advance our understanding of how and why people do and do not maintain physical activity long term.     

A program for studies of altered sleep-wake schedules and performance

Studies of the effects of variations in sleep-wake schedules on human performance tend to run for several days and involve extensive repeated testing in order to take into account time-of-day and cumulative cross-day effects (Broughton & Ogilvie, 1992; Monk, 1991; Webb, 1982). Such research typically addresses issues pertaining to sustained operations and shift work and is often more appropriately conducted in the field. The present paper describes a computer-automated system designed to administer sleep-wake schedules and performance tests, and to store results of such testing in file formats that are easy to access with commercially available statistical packages.