European Journal of Sport Science, vol. 2, issue 5 Physical Activity and Mental Well-being / 1 ©2002 by Human Kinetics Publishers and the European College of Sport Science

Testing the Mediating Role of Physical Acceptance in the Relationship Between Physical Activity and Self-esteem: An Empirical Study With Danish Public Servants Cecilie Thøgersen, Kenneth R. Fox, and Nikos Ntoumanis This study examined the mediating role of physical acceptance in the relationship between physical activity and self-esteem among a sample of Danish public servants. Participants were 148 males and 239 females representing a variety of age groups (the largest group was the 51–55 year olds: n = 88). Questionnaires were administered to measure physical activity, self-esteem, and physical acceptance. A hierarchical multiple regression analysis was carried out to examine the mediating effect of physical acceptance. Following the steps suggested by Kenny (20) to establish mediation, the study found support for a mediating effect of physical acceptance. Furthermore, a MANOVA test revealed that the most physically active participants were significantly more physically satisfied than 3 other less physically active groups. The results suggest that physical acceptance should be taken into consideration when examining the mechanisms by which physical activity may improve mental health and well-being. Key Words: physical activity, physical acceptance, physical satisfaction, selfesteem, mediation Key Points: 1. The study examined the mediating role of physical acceptance in the relationship between physical activity participation and global self-esteem. 2. Danish public servants (N = 395) from five different municipalities took part in the study, representing a range of white-collar occupations. 3. Physical acceptance was a partial mediator in the relationship between physical activity participation and global self-esteem. 4. Physical activity quartiles differed significantly on physical acceptance/satisfaction, but not on self-esteem. 5. The results demonstrate the importance of enhancing physical acceptance through any physical activity intervention designed to improve self-esteem.

C. Thøgersen is with the Department of Sport and Exercise Science at the University of Wales, Aberystwyth, SY23 3DA, UK. K. Fox is with the Department of Exercise and Health Sciences at the University of Bristol, Bristol, BS8 1TN, UK. N. Ntoumanis is with the School of Sport and Exercise Sciences at the University of Birmingham, Birmingham, B15 2TT, UK. 1

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It is becoming increasingly evident that large segments of Western societies suffer from public health problems, such as obesity, cardiovascular diseases, and type II diabetes (34). In an attempt to reduce this prevalence of morbidity among the adult population, the Department of Health (14) in Britain has identified the workplace as an important venue for the introduction of health promotion initiatives. One of the most significant factors contributing to the aforementioned health problems is lack of physical activity (e.g., 4, 27). For example, it has been shown that citizens from many member countries of the European Union do not engage in enough physical activity to maintain satisfactory health (24). There is also increasing evidence that physical activity may be effective in the treatment of clinical mental disorders, in the improvement of the quality of life of those who have been diagnosed with psychological disorders, and in the enhancement of psychological well-being for the general population (17). Although the causal mechanisms underpinning the effect of exercise on measures of psychological well-being have not been determined as yet, consistent relationships have been found between exercise and improvement on several psychological constructs such as depression (10, 25), anxiety (32), life satisfaction (9), mood (5), self-perceptions, and self-esteem (16). A recent review of literature examining the relationship between exercise and self-perceptions indicated that exercise helps people see themselves in a more positive light, as approximately 50% of the studies included in the review have shown a positive impact of exercise on self-esteem (16). In line with this finding, a metaanalysis by Spence and Poon (30) found a small mean effect size (r = 0.22) between physical activity and global self-esteem. Given that self-esteem is a relatively stable construct (i.e., not likely to change considerably as a result of behavioral modifications), these findings altogether indicate that self-esteem might be one of the global indicators of life adjustment that is responsive to physical activity. As noted by Fox (16), the physical self seems to be one of the most likely mechanisms by which exercise participation may influence global self-esteem. For example, body image has been found to be consistently related to global self-esteem (11, 19). In addition, Elrick (15) found that one of the major attractions of exercise, especially for women, is improved appearance. Furthermore, previous studies have found that physical activity shows moderate to strong positive associations with satisfaction with health (8), body appearance, and fitness (12, 13, 31). In addition, randomized controlled studies by King et al. (21, 22) have shown that exercise interventions may improve physical perceptions, including fitness, appearance, physical health, body cathexis, and physical self-worth. Empirical findings, therefore, strongly suggest (a) that physical activity participation may cause improvements in perceptions and satisfaction with various aspects of the physical self, and (b) that physical acceptance may act as a mediator between physical activity and self-esteem. The complex relationships between exercise and self-esteem have been best conceptualized in Sonstroem and Morgan’s exercise and self-esteem model (29). This model specifies that involvement in exercise may influence self-efficacy, or the belief that one can successfully carry out a specific behavior to produce a desired outcome (3). Self-efficacy, in turn, may enhance perceptions of physical competence. In turn, perceptions of physical competence directly influence self-esteem. Perceptions of physical competence also influence physical acceptance. Sonstroem (28) has defined physical acceptance as the “personal regard and liking that people

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hold for themselves and for their attributes irrespective of their levels of perceived competence” (p. 7). Physical acceptance is also hypothesized to influence selfesteem directly. However, the exercise and self-esteem model does not hypothesize any direct relationship between exercise or self-efficacy and physical acceptance. In contrast to physical competence, physical acceptance has hardly received any research attention. Baldwin and Courneya (2) carried out the only study that has examined the physical acceptance component of the exercise and self-esteem model. In their study, physical acceptance was operationalized in terms of physical satisfaction. In view of their study, the present study adopted questions on physical satisfaction to represent the physical acceptance component. Clearly, there is a need to further examine the physical acceptance dimension and look at how it relates to exercise and self-esteem. The present study is addressing this research need. Specifically, it is hypothesized that physical acceptance directly predicts self-esteem. Clearly, an assumption made here is that the physical acceptance construct used here reflects the theoretical construct proposed by Sonstroem and Morgan (29). However, two fundamental differences exist between the exercise and self-esteem model and the model tested in the present study. First of all, given the findings of previous studies which have shown that physical activity is directly related to elements of physical satisfaction, the model in the present study hypothesized a direct link between physical activity and physical acceptance (see Figure 1). Second, the present study adopted the more inclusive concept of physical activity rather than exercise. This is because findings from intervention studies have shown that body image and physical self-perceptions may be enhanced as a result of moderate activities such as walking (16, 33), and therefore not just more intensive forms of exercise. In view of the above, the main aim of the present study was to examine the mediating effect of physical acceptance in the relationship between physical activity and self-esteem. In addition, it was hypothesized that significant differences would exist between physical activity quartiles in physical acceptance and selfesteem. Specifically, more active individuals were hypothesized to be significantly more accepting of their physical attributes and have higher levels of self-esteem than less physically active individuals.

Methods Participants The participants (N = 395) were male (n = 148) and female (n = 239) Danish public servants (8 did not report their gender). Five different municipalities in Denmark were used, and the objective was to obtain a sample broadly representative of Danish public servants. The participants represented a range of different whitecollar occupations (such as teachers and administrators) in each municipality. Using 5-year intervals, 10 age groups were created, representing the ages of 20 to 65 years. The group with the highest frequency was the 51–55 year olds (n = 88), followed by the 46–50 year olds (n = 69). Procedures Initial letters of contact were sent to eight different municipalities: Herning Kommune, Kolding Kommune, Næstved Kommune, Odense Kommune, Randers Kommune,

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Tornved Kommune, Viborg Kommune, and Aalborg Kommune. Five of these (Kolding, Næstved, Randers, Tornved, and Aalborg Kommune) agreed to take part in the study, and the contact persons for each municipality directed various departments of their municipality to inform the employees about the study. An information sheet, explaining the purpose of the study, accompanied the questionnaires, which were sent to the five municipalities. Employees were informed that by responding to the questionnaire, they provided their consent to use their replies for analysis. However, it was also stated that anonymity was guaranteed, in addition to the assurance of complete confidentiality of their replies. Instruments The instruments used in this study were translated from English to Danish by the first author. In addition, another bilingual person with expert knowledge of both languages translated the questionnaires independently. Discrepancies between the two translations were compared, and the wording was changed where necessary until consensus was reached. The Self-esteem Scale The self-esteem questionnaire was developed by Rosenberg (1965) to measure global self-esteem, making it an appropriate instrument for a large variation of settings. It consists of a 10-item Guttman scale (7), and the responses are categorized on a Likert form scale ranging from 1 (strongly agree) to 4 (strongly disagree). Five items have positive wording and negative response categories (i.e., 4–1), and the remaining five items have negative wording and positive response categories (i.e., 1–4). Bowling (7) noted that there is no agreement among researchers on the scoring of the scale. A summing scale was used in the present study to get the global selfesteem score of each participant. Bowling (7) has reported that item inter-correlations range from 0.56 to 0.83, with an alpha coefficient of 0.74. A test-retest reliability coefficient of 0.85 has also been reported in the literature (7). Physical Satisfaction To measure physical satisfaction, a new scale that consisted of four items was constructed. Participants were asked to rate their levels of satisfaction with their appearance, overall health, weight, and perceived fitness. These items were summed together into one scale in this study to give an overall score of satisfaction with physical aspects of the self. The scale was measured on a 6-point scale ranging from 0 (completely unhappy or dissatisfied) to 5 (completely happy or satisfied). The Aerobics Center Longitudinal Study Physical Activity Questionnaire (ACLS-Q) The questionnaire developed by Blair (6) assesses physical activity “within the last month” and its association with physical health. The questionnaire provides questions on a range of physical activities, including sports, exercise, and lifestyle physical activities. Participants were asked to provide self-reported quantitative information regarding those physical activities they performed regularly (at least once per

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week) and which were performed for at least 15 min at a time for the last month. Frequency per week, intensity level, and duration per session were assessed. Metabolic Equivalents The participants were divided into physical activity quartiles based on their selfreported levels of physical activity. The classifications of the groups were based on the frequency, duration, and intensity of each of the physical activities that the individuals took part in. The intensity for each activity was based on metabolic equivalents (METs), where 1 MET is the oxygen consumption required at rest. MET-hr/wk takes into consideration frequency, duration, and intensity of exercise and were derived from the formula presented by Blair (6): (sessions/week) (minutes/session) (hour/min) (METs) = MET-hr/wk. The MET-hr/wk values for each activity were then added to obtain an overall MET-hr/wk score for each participant. This calculation allowed for an estimation of self-reported energy expenditure. The respective METs for each kind of exercise were obtained from the work by Ainsworth, Haskell, Leon, Jacobs, Montoye, Sallis, and Paffenbarger (1), in which “the intensity of energy cost values were derived from the best available published and unpublished data” (p. 72).

Results Factor Analysis of the Physical Satisfaction Scale Because the scale measuring physical satisfaction was new, it was subjected to exploratory factor analysis (principle axis factoring) using varimax rotation. We found that the scale produced one factor with an Eigenvalue of 2.41, explaining 60.21% of the item variance. Hence, these results provide initial evidence for the coherence of the instrument. Internal reliabilities Internal reliability analyses were carried out on Rosenberg’s self-esteem scale and the physical satisfaction scale. The internal reliability coefficients were satisfactory for both scales ( = 0.77 for the physical satisfaction scale, and = 0.84 for Rosenberg’s self-esteem scale). Regression Analyses Regression analyses were carried out to examine the mediating effect of physical acceptance in the relationship between physical activity and self-esteem (see Figure 1). A significance level of p < .05 was adopted. Kenny (20) suggests three steps to establish mediation and a further fourth step to examine whether there is full mediation. The first step shows that the initial variable predicts the outcome variable. The second step examines whether the initial variable predicts the mediator. The third step tests whether the mediator predicts the outcome variable, when the initial variable is controlled for. Finally, the fourth step aims to establish whether the mediator completely mediates the path between the initial variable and the outcome variable—that is, whether this path (established in step 1) is reduced to zero.

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Figure 1 — The results of a hierarchical multiple regression analysis testing the mediating role of physical acceptance in the relationship between physical activity and selfesteem.

The results showed that the first step was not met (b = .08; p = .11). In step two, a simple regression analysis was carried out in which total physical activity participation in the form of MET-hrs/wk served as the independent variable, and physical satisfaction (satisfaction with health, appearance, weight, and fitness) was the dependent variable. The enter method was used, which evaluates what the independent variable adds to the prediction of the dependent variable. The results showed that physical activity significantly predicted physical satisfaction (b = .19; p = .000). The regression, however, only accounted for 4% of the variance. To test step 3, a multiple hierarchical regression analysis was carried out. The results showed that physical satisfaction did indeed predict self-esteem when controlling for physical activity (b = .33; p = .000). Hence, it may be concluded that the second and third steps were successfully met. In the fourth step, after controlling for physical satisfaction, the effect from physical activity to self-esteem was reduced from b = .08 to b = .02. This finding demonstrates that there is a partial mediation; complete mediation would require that the path is reduced to b = 0. According to Kenny (20) and MacKinnon (23), only steps 2 and 3 are necessary to claim any mediation effect. Step 1 does not have to be met. This is because, according to Gavin (18), the independent variable may not significantly predict the dependent variable when there are several mediating variables in operation. It might have been the case that other mediators were in operation, but they were not measured. In brief, the present study showed that physical acceptance, operationalized as physical satisfaction, seems to be one of the mediating variables in the relationship between physical activity and self-esteem. Differences Between Physical Activity Quartiles on Self-esteem and Physical Satisfaction A multivariate analysis of variance was carried out to examine the differences between physical activity quartiles on physical satisfaction and self-esteem. The MANOVA was significant (Pillai’s criterion = .04, F6, 670 = 2.53; p < .05). Univariate results are shown in Table 1. As seen in Table 1, significant differences existed on physical satisfaction. Specifically, the significant differences were located between the 0–25th and the 75–100th quartile (p = .00), between the 25–50th and the 75–100th quartile (p = .04), and between the 50–75th and the 75–100th quartile (p = .03).

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Table 1 Univariate Analyses for Physical Activity Quartiles in Self-esteem and Physical Satisfaction (df = 3, 335) Self-esteem Physical activity quartiles 0–25th 25–50th 50–75th 75–100th

Physical satisfaction

M

SD

M

SD

33.61a 32.99a 33.38a 34.13a F 1.17

.44 .44 .44 .45 p .32

13.24a 13.65a 13.61a 15.02b F 4.46

.37 .37 .37 .37 p .00

Note. Quartiles with the same subscripts in the same column do not differ significantly at p < .05.

Discussion The main purpose of the present study was to examine empirically the mediating effect of physical acceptance in the relationship between self-reported physical activity and self-esteem. The findings largely supported the main hypothesis of the study, which stated that physical acceptance acts as a mediating variable between physical activity and self-esteem. It was also shown that significant differences existed between physical activity quartiles on physical satisfaction. Although Sonstroem and Morgan’s exercise and self-esteem model (29) clearly recognizes the importance of physical acceptance as an influencing variable on selfesteem, their model does not specify any direct link between exercise and physical acceptance. The present study suggests that physical activity does indeed predict physical acceptance, operationalized as satisfaction with physical elements of the self. Although the variance explained by physical activity was relatively small (4%), previous studies have also found that satisfaction with physical health and appearance is often enhanced through physical activity (8, 12, 13, 31). Several issues should be considered when interpreting the results of this study. First of all, it is possible that more intense forms of physical activity are needed to increase satisfaction with the physical self rather than general physical activity participation that include active living such as gardening, and cycling to and from work. It is possible that a certain type, intensity level, duration, and frequency of exercise is needed to create positive mental health benefits of exercise. For example, as noted in a review by Fox (16), resistance training seems to be more effective in enhancing physical well-being (in the form of body image and physical self-worth) than other aerobic types of exercise. Not enough is known about the optimal frequency, intensity, and duration of exercise that is needed to produce large and positive changes in perceptions and satisfaction of the physical self, and this issue should therefore be a priority of future research. This issue may explain why the variance explained by physical activity in physical acceptance was relatively

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small. In addition, results showed that physical acceptance predicted self-esteem. This is a significant result when one takes into consideration that self-esteem is a global and stable construct, and consequently more resistant to change. As has been shown before, different dimensions of the physical self seem to be very important to many people’s sense of self. Second, although parallels are drawn between the tested model and Sonstroem and Morgan’s (29) exercise and self-esteem model, it is very possible that the physical satisfaction measure does not accurately capture the theoretical construct of physical acceptance as suggested by Sontroem and Morgan. However, given the paucity of research examining the physical acceptance dimension of their model, the journey has to start somewhere. However, it should be noted that the present study only represents a preliminary effort to test this construct. Indeed, future research should aim to develop a comprehensive questionnaire that accurately represents the physical acceptance dimension. Third, the physical satisfaction measure may be considered a construct that assesses ambiguous physical attributes, such as health and appearance. It has been suggested that more self-serving bias takes place when people are asked to rate their more ambiguous attributes compared to more unambiguous attributes such as strength, hips, and thighs (26). Powell et al. (26) propose that ambiguity can encourage the participant to “create his or her own idiosyncratic definitions of traits and abilities” (p. 1957). Self-enhancement may therefore take place in which the individual may more freely choose which criteria he or she considers the best to cast him- or herself in the most positive light. It is therefore possible that physically inactive individuals, who in fact feel dissatisfied with their strength, hips, and thighs, judge themselves to be satisfied on the ambiguous attributes. Consequently, this process may mask any actual positive effects of physical activity participation on less ambiguous physical attributes. Despite these potential problems, the present study nonetheless found support for a mediating effect of physical acceptance in the relationship between physical activity and self-esteem. This suggests that physical acceptance should be given more research attention in the future. Although the physical satisfaction construct had an acceptable factor structure, this study only represented a preliminary effort to capture this construct. In view of the above, it is therefore possible that with an improved physical satisfaction measure, the results would have shown a stronger mediating effect of physical acceptance. In conclusion, the model tested in the present study, which was based on empirical findings in the literature, found support for a mediating effect of physical acceptance in the relationship between physical activity and self-esteem. It seems that satisfaction with health, appearance, weight, and fitness may explain any increases in self-esteem that may take place as a result of physical activity participation.

References 1. Ainsworth BE, Haskell WL, Leon AS, Jacobs DR, Montoye HJ, Sallis JF, Paffenbarger RS. 1993. Compendium of physical activities: Classification of energy costs of human physical activities. Med Sci Sport Exerc 25:71-80. 2. Baldwin MK, Courneya KS. 1997. Exercise and self-esteem in breast cancer survivors: An application of the Exercise and Self-Esteem Model. J Sport Exerc Psychol 19:347358.

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3. Bandura A. 1986. Social foundations of thought and action. Englewood Cliffs, NJ: Prentice-Hall. 4. Berlin JA, Colditz GA. 1990. A meta-analysis of physical activity in the prevention of coronary heart disease. Am J Epid 132:612-28. 5. Biddle SJH. 2000. Emotion, mood and physical activity. In: Biddle SJH, Fox KR, Boutcher SH, editors. Physical activity and psychological well-being. London: Routledge. p. 63-87. 6. Blair SN. 1997. The Aerobics Center Longitudinal Study physical activity questionnaire. Med Sci Sport Exerc 29(Suppl.):S10-S14. 7. Bowling A. 1997. Measuring health: a review of quality of life measurement scales. Buckingham: Open University Press. 8. Brown DR, Wang Y, Ward A, Ebbeling CB, Fortlage L, Puleo E, Benson H, Rippe JM. 1995. Chronic psychological effects of exercise and exercise plus cognitive strategies. Med Sci Sport Exerc 27:765-75. 9. Caspersen CJ, Powell KE, Merritt RK. 1994. Measurement of health status and wellbeing. In: Bouchard C, Shephard RJ, Stephens T, editors. Physical activity, fitness, and health: international proceedings and consensus statement. Champaign, IL: Human Kinetics. p. 180-202. 10. Craft LL, Landers DM. 1998. The effect of exercise on clinical depression and depression resulting from mental illness: a meta-analysis. J Sport Exerc Psychol 20:339-57. 11. Davis C. 1997. Body image, exercise, and eating disorders. In: Fox KR, editor. The physical self: from motivation to well-being. Champaign, IL: Human Kinetics. p. 14374. 12. Davis C, Cowles M. 1991. Body image and exercise: A study of relationships and comparisons between physically active men and women. Sex Roles 25: 33-44. 13. Davis C, Fox J. 1993. Excessive exercise and weight preoccupation in women. Add Beh 18:201-11. 14. Department of Health. 1999. White paper. Saving lives: our healthier nation. London: HMSO. 15. Elrick H. 1996. Exercise is medicine. Phys Sportsmed 24:72-78. 16. Fox KR. 2000. The effects of exercise on self-perceptions and self-esteem. In: Biddle SJH, Fox KR, Boutcher SH, editors. Physical activity and psychological well-being. London: Routledge. p. 88-117. 17. Fox KR, Boutcher SH, Faulkner GE, Biddle SJH. 2000. The case for exercise in the promotion of mental health and psychological well-being. In: Biddle SJH, Fox KR, Boutcher SH, editors. Physical activity and psychological well-being. London: Routledge. p. 1-9. 18. Gavin M. 2002, April 29. Analyzing mediational model. Message posted to [email protected]. 19. Harter S. 1990. Causes, correlates, and the functional role of global self-worth: a lifespan perspective. In: Sternberg RJ, Kolligian Jr. J., editors. Competence considered. New Haven: Yale University Press. p. 67-97. 20. Kenny DA. 1999, July 5. Mediation. Retrieved from http://nw3.nai.net/~dakenny/ mediate.htm. 21. King AC, Taylor C, Haskell WL. 1993. Effects of differing intensities and formats of 12 months of exercise training on psychological outcomes in older adults. Health Psychol 12:292-300.

01.Thogerson

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22. King AC, Taylor CB, Haskell WL, DeBusk RF. 1989. Influence of regular aerobic exercise on psychological health: a randomized, controlled trial of healthy middle-aged adults. Health Psychol 8:305-24. 23. MacKinnon DP. 1999. Statistical mediation. Retrieved December 19, 2000, from Arizona State University, Research in Prevention Laboratory Web site: http:// www.public.asu.edu/~davidpm/ripl/mediate.htm. 24. Martinez-Gonzalez MA, Varo JJ, Santos JL, De Irala J, Gibney M, Kearney J, Martinez JA. 2001. Prevalence of physical activity during leisure time in the European Union. Med Sci Sport Exerc 33:1142-46. 25. Mutrie N. 2000. The relationship between physical activity and clinically defined depression. In: Biddle SJH, Fox KR, Boutcher SH, editors. Physical activity and psychological well-being. London: Routledge. p. 46-62. 26. Powell JL, Matacin ML, Stuart AE. 2001. Body esteem: An exception to self-enhancing illusions? J Appl Soc Psychol 31:1951-78. 27. Powell KE, Thompson PD, Casperson CJ, Kendrick JS. 1987. Physical activity and the incidence of coronary heart disease. Ann Rev Publ Health 8:253-87. 28. Sonstroem RJ. 1997. The physical self-system: a mediator of exercise and self-esteem. In: Fox KR, editor. The physical self: from motivation to well-being. Champaign, IL: Human Kinetics. p. 3-26 29. Sonstroem RJ, Morgan WP. 1989. Exercise and self-esteem: rationale and model. Med Sci Sport Exerc 21:329-37. 30. Spence JC, Poon P. 1997. The effect of physical activity on self-concept: a meta-analysis. Alberta Centre for Well-Being: Research Update 4:4. 31. Sørensen M, Anderssen S, Hjerman I, Holme I, Ursin H. 1997. Exercise and diet interventions improve perceptions of self in middle-aged adults. Scand J Med Sci Sport 7:312-20. 32. Taylor AH. 2000. Physical activity, anxiety, and stress. In: Biddle SJH, Fox KR, Boutcher SH, editors. Physical activity and psychological well-being. London: Routledge. p. 1045. 33. Tucker LA, Mortell R. 1993. Comparison of the effects of walking and weight training programs on body image in middle-aged women: an experimental study. Am J Health Prom 8:34-42. 34. United States Department of Health and Human Services. 1996. Physical activity and health: a report of the Surgeon General Report. Atlanta, GA: Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion.

About the Authors Cecilie Thøgersen is a lecturer at the University of Wales, Aberystwyth. Her research is primarily concerned with the contribution of physical activity and exercise to the wellbeing of corporate populations. Ken Fox, PhD, is a Professor in the Department of Exercise and Health Sciences at the University of Bristol. His major research interest is in the psychology of exercise. His book entitled The Physical Self: From Motivation to Well-Being was the first of its type in the field, and he recently co-edited a book called Physical Activity and Psychological Well-being. Nikos Ntoumanis, PhD, is a lecturer at the School of Sport and Exercise Sciences at the University of Birmingham. His research interests primarily focus on the study of motivation in physical activity contexts.

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