Grit, conscientiousness, and the transtheoretical model of change for exercise behavior

In this article, we introduce brief self-report and informant-report versions of the Grit Scale, which measures trait-level perseverance and passion for long-term goals. The Short Grit Scale (Grit-S) retains the 2-factor structure of the original Grit Scale (Duckworth, Peterson, Matthews, & Kelly, 2007) with 4 fewer items and improved psychometric properties. We present evidence for the Grit-S's internal consistency, test-retest stability, consensual validity with informant-report versions, and predictive validity. Among adults, the Grit-S was associated with educational attainment and fewer career changes. Among adolescents, the Grit-S longitudinally predicted GPA and, inversely, hours watching television. Among cadets at the United States Military Academy, West Point, the Grit-S predicted retention. Among Scripps National Spelling Bee competitors, the Grit-S predicted final round attained, a relationship mediated by lifetime spelling practice.

Environmental determinants of health are receiving growing attention in the literature, although there is little empirical research in this area. The Study on Environmental and Individual Determinants of Physical Activity (known as the SEID project) was a social ecological project that examined the relative influence of individual, social environmental and physical environmental determinants of recreational physical activity. It involved a community survey of 1803 healthy workers and home-makers aged 18-59 years living in a 408 km2 area of metropolitan Perth, Western Australia. Physical environmental determinants were mainly conceptualised as spatial access to popular recreational facilities. Overall, 59% of respondents exercised as recommended. Recreational facilities located near home were used by more respondents than facilities located elsewhere. The most frequently used facilities were informal: the streets (45.6%); public open space (28.8%) and the beach (22.7%). The physical environment's directs the influence on exercising as recommended was found to be secondary to individual and social environmental determinants. Nevertheless, accessible facilities determined whether or not they were used and in this way, support and enhance the achievement of recommended levels of physical activity behaviour by providing opportunities. The results suggest that access to a supportive physical environment is necessary, but may be insufficient to increase recommended levels of physical activity in the community. Complementary strategies are required that aim to influence individual and social environmental factors. Given the popularity of walking in the community, it is recommended that greater emphasis be placed on creating streetscapes that enhance walking for recreation and transport.

Researchers examining theory-based, physical activity (PA) interventions postulate that interventions are effective by changing theoretical constructs hypothesized to mediate the relationship between the intervention and PA behavior. Research indicates that PA interventions are effective for increasing PA behavior. However, whether effective interventions are due to predicted changes in theoretical constructs remains poorly understood. Studies that examined theoretical constructs (i.e., mediators) in PA interventions of adults or children, which used experimental designs and met other criteria for evaluating mediation, were collected via literature searches, personal searches of files, and personal communications. Only studies examining the direct effect of the intervention on the hypothesized mediator were considered relevant for this study. Based on our criteria, the adult literature search yielded ten studies and the child literature search yielded two studies. The most common mediators examined included behavioral processes of change, cognitive processes of change, self-efficacy, decisional balance, social support, and enjoyment. Research indicates that behavioral processes are likely mediators. There was some support for the importance of self-efficacy as a mediator. Few studies have used statistically recommended methods to examine mediators in PA intervention studies. Therefore, definitive conclusions about the importance of the mediators reviewed are not possible at this time. Additional PA mediator-intervention studies using recommended statistical methods are necessary to truly test if theory-based PA interventions are effective due to predicted changes in theoretical constructs.