OBJECTIVE Despite the well-established health benefits of physical activity, the role of exercise for eating disorders (ED) is controversial; thus dictating a need for a better understanding of the mechanisms of exercise and ED. The purpose of our study was to examine a conceptual model that hypothesizes regular exercise without psychological compulsion might impart beneficial effects for preventing and treating ED. METHOD University students (N = 539) completed self-report assessments of quality of life, exercise level, ED risk and exercise dependence symptoms. Structural equation modelling analysis was undertaken to examine the conceptual model's proposed relationships. RESULTS Mediation analysis and model comparison tests showed that the partially mediated model without the physical well-being latent construct fit the data best. DISCUSSION Our results provided initial support for the conceptual model by showing that the psychological benefits, but not the physical benefits, conveyed by exercise were associated with reduced ED risk.

This study tested five confirmatory factor analytic (CFA) models of the Positive Affect Negative Affect Schedule (PANAS) to provide validity evidence based on its internal structure. A sample of 223 club sport athletes indicated their emotions during the past week. Results revealed that an orthogonal two-factor CFA model, specifying error correlations according to Zevon and Tellegen's mood content categories, provided the best fit to our data. In addition, parameter estimates for this model suggest that PANAS scores are reliable and explain large proportions of item variance. Taken together with previous research, the findings further suggest that the PANAS may be a higher-order measure of affect and includes several consistently problematic items. The authors recommend that affect researchers attempt to improve the PANAS by (a) revising consistently problematic items, (b) adding new items to better capture mood content categories, and (c) providing additional internal structure validity evidence through a diagonally weighted least squares estimation of a second-order PANAS CFA model.

We assessed the factor structure of a revised version of the Exercise Imagery Inventory (ELI; Giacobbi, Hausenblas, & Penfield, 2005), second-order interrelationships for cognitive and motivational forms of mental imagery, and associations with exercise behavior and barriers self-efficacy. A convenience sample of 358 (M age = 20.55 years, SD = 3.88) college students completed the EII-revised (EII-R), a measure of barriers self-efficacy and the Leisure-Time Exercise Questionnaire. The EII-R demonstrated reliability and factorial validity with good model fit statistics. We observed second-order relationships among scale scores and discriminant validity evidence that distinguished cognitive (e.g., exercise technique, exercise routines) and motivational (e.g., appearance/health, exercise self-efficacy, exercise feelings) factors. The second-order imagery factors were significantly and moderately associated with barriers self-efficacy and exercise behavior.

Objectives: To assess whether exercise was associated with increased positive and decreased negative affect for university students during academically demanding times. Design: Within-subjects daily diary study. Methods: Fifty-nine university students completed the LTEQ [Godin, G., & Shephard, R.J. (1985). A simple method to assess exercise behavior in the community. Canadian Journal of Applied Sport Science, 10, 141-146], cognitive appraisals of daily events [Lazarus, R. S. (1999). Stress and emotion: A new synthesis. New York: Springer], and the PANAS [Watson, D., Clark, L. A., & Tellegen, A. (1988). Development and validation of brief measures of positive and negative affect: The PANAS scales. Journal of Personality and Social Psychology, 54, 1063-1070] for 14 days immediately prior to the final examination period. Results: Our hypotheses were partially supported as threat appraisals were significantly associated with decreased positive affect on days closer to the final examination period. Contrary, to our hypotheses exercise was not independently associated with increased positive and decreased negative affect. However, the interaction between exercise and day was significant as participants experienced increased positive affect during the last 3 days of data collection immediately preceding the final exam period. There was also a significant exercise by threat interaction with follow-up tests showing the exercise/negative affect relationship was significantly moderated by threat appraisals only when academic events were appraised as mildly threatening. Conclusions: These findings suggest that exercise behavior might be an effective way for college students to cope with stress especially during academic demanding times. (C) 2006 Elsevier Ltd. All rights reserved.