This is an excerpt from Psychological Benefits of Exercise and Physical Activity, The by Jennifer L. Etnier.
Some evidence shows that body image concerns are related to the experience of clinical disorders. Although this evidence is correlational in nature, the findings might have important implications relative to the treatment of these clinical disorders.
Muscle dysmorphia is defined as a pathological preoccupation with muscularity, and it tends to be experienced by men. Pope and associates (2000) asked college-aged men from Austria, France, and the United States to identify the body shape that was ideal for them and that they thought would be most attractive to women. Across all three countries, men consistently chose an ideal body that was approximately 28 pounds (13 kg) more muscular than they perceived themselves to be. They also found that men thought that women preferred a body that was 27 to 32 pounds (12-15 kg) bigger than they themselves were. Ironically, when given the opportunity to select the body size they found most attractive, the women in the study chose normal-weight men.
Clinical Eating Disorders and Disordered Eating
Because of the expected link between body image dissatisfaction, disordered eating, and eating disorders, prevalence data for disordered eating and for eating disorders is relevant for further understanding the importance of a potential positive link between exercise and body image. To clarify, clinical eating disorders are diagnosed by psychologists or physicians based on persistent abnormal eating habits that impair physical and mental health and that limit an individual’s ability to function. Two well-known and relatively common clinical eating disorders are anorexia nervosa (anorexia) and bulimia nervosa (bulimia). Anorexia is characterized by lower weight than normal for height, a fear of gaining weight, and a distorted perception of body weight or shape. It is potentially life-threatening because of the enduring efforts to lose weight when a person is already underweight. Bulimia is characterized by bingeing and purging and a sense of a lack of control over eating. It is also life-threatening because the resultant electrolyte imbalances from repeated purging can lead to cardiac or respiratory arrest. Disordered eating is defined as behaviors that fall short of a clinical diagnosis of an eating disorder but that demonstrate that the individual has an unhealthy relationship with food and weight. Examples of disordered eating include restrictive eating, compulsive eating, and irregular or inflexible eating patterns. Disordered eating is a risk factor for the development of an eating disorder.
Among high school students in the United States, 16% reported practicing disordered eating behaviors in the past 30 days, with a larger percentage of girls reporting these behaviors than boys (Beccia et al., 2019). When asked about these behaviors within the past year, 50% of girls and 38% of boys reported practicing unhealthy weight-control behaviors (e.g., fasting, skipping meals, taking diet pills), and 46% of girls and 31% of boys dieted (Neumark-Sztainer et al., 2012). These findings are consistent with a more recent survey that also looked at the influence of race or ethnicity on the findings. Simone and colleagues (2022) assessed unhealthy weight-control behaviors and binge eating in the past year among men and women aged 11 to 33 years. Results generally showed that girls reported performing these behaviors more frequently than did men (figure 12.2). In terms of diagnosis, in the United States it is estimated that 8.4% of women and 2.2% of men will be diagnosed with a clinical eating disorder over their lifetime, with the concerning finding that the prevalence has more than doubled from 2000-2006 to 2013-2018 (Galmiche et al., 2019).
If you believe you have an eating disorder and are ready to seek help, please contact your university counseling department or a mental health care professional. If you are concerned about a friend or relative whom you believe might have an eating disorder, educate yourself about appropriate ways to intervene and remember to lead with compassion and care rather than phrases that might convey a judgment or evaluation relative to body size, appearance, or eating behaviors. Visit sites maintained by these organizations to learn more or use the hotlines (available on weekdays) to speak with trained volunteers.
National Eating Disorders Hotline: 1-800-931-2237
National Association of Anorexia Nervosa and Associated Disorders: 1-630-577-1330
Mechanisms and Mediators
As mentioned, it is likely that changes in body image in response to exercise can mediate the effects of exercise on other psychological outcomes such as depression and anxiety. However, we also must consider the mechanisms and mediators that explain any observed benefits of exercise on body image. The mechanisms that have been proposed include real or perceived changes in various measures of fitness (aerobic fitness, strength, body composition, flexibility) and increases in self-efficacy (situation-specific self-confidence).
Martin Ginis and associates (2012) proposed that there are three categories of variables that can act as mechanisms or mediators of the link between exercise and body image. These are objective changes in physical fitness (mechanism), perceived changes in physical fitness (mediator), and changes in self-efficacy (mediator). Martin Ginis and associates reviewed the literature to examine the evidence relative to each of these potential variables. They found 13 studies that had conducted appropriate statistical tests to consider the effects of an exercise intervention on body image and one or more of the hypothesized mechanisms or mediators and that also had looked at correlations between body image and the purported mechanisms or mediators. Only three of the studies looked at self-efficacy as a mechanism, but all three found positive results. That is, even after controlling for objective change in physical fitness, changes in self-efficacy were found to predict changes in body image. All of the studies included an objective measure of fitness as a potential mechanism. However, results were not consistent across the studies, and even in those where a significant association was observed, it only accounted for approximately 15% of the variance in body image. Overall, Martin Ginis and associates concluded that not much support has been shown for the role of objective fitness measures in terms of explaining the benefits for body image. They suggested that this is most likely because the actual amount of change in fitness is not important to a person’s evaluation of their body relative to their perceived ideal. In other words, if a person were to begin an exercise program and improve their ability to run a mile, that change would only be important if they perceived that the fitness gain was moving them closer to their perceived ideal in terms of body shape. One study in their review included a measure of perceived change in fitness rather than absolute change. Martin Ginis and associates (2005) implemented a 12-week strength-training program and found that for both men and women, changes in perceptions of muscularity and strength were associated with changes in body satisfaction and SPA. Thus, overall, Martin Ginis and associates concluded that support was consistent for self-efficacy as a mechanism, and the one study that looked at perceived changes in measures of fitness found positive results. However, findings for objective measures of fitness are mixed, and Martin Ginis and associates concluded that these changes did not seem critical for improvements in body image.
Given that body image includes perceptions, thoughts, and feelings and that body image can influence behavior, measures of body image concerns exist that reflect each of these aspects of the construct. One of the challenges in this body of research is that numerous measures have been developed (over 50 were reported in Thompson, 2004), so a researcher should be sure to choose a measure that addresses the specific aspect of body image that is of interest and that has been shown to be valid and reliable with the population of interest (Thompson, 2004).
Body Perception and Dissatisfaction
The Body Cathexis Scale (Secord and Jourard, 1953) was one of the first to be developed to assess body satisfaction. This scale includes assessment of satisfaction with various body parts (including many that are not weight-related such as eyes, ears, and nose) and measures of satisfaction with bodily functions related to physical activity participation (e.g., energy level and coordination). It consists of 46 items that are rated on a 5-point scale with the anchors of “Have strong feelings and wish change could somehow be made” and “Consider myself fortunate.” This survey is commonly used in the exercise literature.
Measures of discrepancies between a person’s ideal body image and their perceived body image (body perception) provide another way of assessing a body dissatisfaction score. In these measures, participants see silhouettes of generic body shapes, computer-generated images of various body shapes, or their own body shown in its actual proportions and then in computer-generated proportions below and above actual body weight. Existing measures include silhouettes developed by Stunkard, Sorenson, and Schulsingser (1983), modifications of these in the Body Silhouette Scale modified for children and preadolescents (Vernon-Guidry and Williamson, 1996), and photographs in the Children’s Body Image Scale (CBIS) (Truby and Paxton, 2002). The CBIS includes images of boys and girls between 7 and 12 with seven levels of adiposity ranging from the 3rd to the 97th percentile for BMI. Children are asked to identify the image that most closely approximates their body size (body perception) and then to identify the image showing the body size they would like to be. The difference between these two reflects their satisfaction (if they choose the same number to answer both questions) or dissatisfaction (the difference between the two numbers given to answer the questions) with their body size.
Measures that assess thoughts and feelings about body image (the affective component) include the Tennessee Self-Concept Scale (TSCS) (Fitts, 1965) and the body attractiveness subscale of the Physical Self-Perception Profile (PSPP, described in more detail in chapter 11). The TSCS consists of 76 items when used with children (7-14 yr) and 82 items when used with older children and adults (over 13 yr). Participants respond on a scale of 1 to 5, from “Always false” to “Always true,” and example items include “I am an attractive person” and “I feel happy most of the time.” It includes a subscale that is focused on physical self-concept, and normative data is available for ages 7 to 90 years.
Body-related behaviors are often assessed using self-report. The most commonly used measure is the Body Checking Questionnaire (BCQ), a 23-item scale that was designed to assess these behaviors using stereotypically female behaviors (Reas et al., 2002). The Male Body Checking Questionnaire (MBCQ) is a 19-item scale that was created to allow for the assessment of behaviors that more likely would be observed in men. In demonstrating the validity and reliability of this scale, the developers confirmed that the scale had good psychometrics for use with men but was not appropriate to be used with women (Hildebrandt et al., 2010).
To assess drive for muscularity, researchers have used a variety of self-report measures including the Male Body Attitudes Scale (MBAS) (Tylka et al., 2005), the Drive for Muscularity Scale (DMS) (McCreary and Sasse, 2000), the Drive for Muscularity Attitudes Questionnaire (DMAQ) (Morrison et al., 2004), and the Muscle Dysmorphic Disorder Inventory (MDDI) (Hildebrandt et al., 2004). The MBAS is the most comprehensive of these scales because it is the only one that provides measures of dissatisfaction relative to muscularity, height, and weight, and it includes questions about six different body areas. The DMS and the DMAQ are also commonly used, but they are limited in that the DMS only provides measures of muscularity-oriented body image and behaviors to increase muscularity, while the DMAQ provides a single score of attitudes toward muscularity. Further, neither of these provides a measure of dissatisfaction, and both only assess attitudes toward three body areas. The MDDI assesses three aspects of muscle dysmorphia by calculating scores for desire for size, appearance anxiety and avoidance, and functional impairment. Desire for size questions focus on respondents’ desire to be bigger, more muscular, or stronger. Appearance anxiety and avoidance questions ask respondents about behaviors that are designed to hide body size (e.g., wearing loose clothing) and anxiety about body exposure. The functional impairment questions revolve around behaviors and emotions relative to exercise. This questionnaire also provides a total score.
Evidence Relative to Exercise and Body Image
The literature on exercise and body concerns is relatively small compared to other outcomes in exercise psychology. In empirical studies, researchers have tested relationships using correlational or cross-sectional designs and intervention studies as is similar to previous bodies of evidence we have reviewed. But single-group studies also have been commonly conducted to explore the potential of physical activity relative to body image. In single-group studies physical activity is manipulated for a single group so that changes in the outcome variable (e.g., body image concerns) can be observed from pretest to posttest. Because no control group exists, conclusions are limited to those of association and cannot be used to draw conclusions about cause and effect. Despite the relatively smaller body of empirical evidence, several meta-analytic reviews have been conducted to summarize the results of correlational, single-group, and experimental studies. These are reviewed first, and then we turn our attention to a consideration of the effects of exercise (or sport participation) on body image and the impact on disordered eating.
single-group studies—When physical activity is manipulated for a single group so that changes in the outcome variable (e.g., body image concerns) can be observed from pretest to posttest, this is called a single-group study.
Hausenblas and Fallon (2006) meta-analytically reviewed findings from 121 studies identified as interventions with an exercise group and a control group, single-group studies that included only pre- and post-measures for an exercise group, or correlational and cross-sectional studies in which a relationship between physical activity behavior and body image was reported or body image was compared between an exercise group and a nonexercise group. Although the largest effect size was observed for correlational studies (ES = 0.41), a positive effect also was observed for the single-group (ES = 0.24) and intervention (ES = 0.27) studies (figure 12.3). Because larger effects were observed when looking at long-term physical activity behavior, as is the case with the correlational studies, compared to shorter-term intervention studies, this difference in effect sizes might suggest that longer interventions are necessary to observe greater benefits. However, the small positive effect for intervention studies is promising in suggesting that a causal relationship might exist between exercise participation and improvements in body image and that this can be observed after relatively short-term exercise participation. With respect to exercise mode, Hausenblas and Fallon reported larger effects for interventions in which both aerobic and anaerobic exercise were used (ES = 0.45) compared to either aerobic exercise alone (ES = 0.25) or anaerobic exercise alone (ES = 0.27) (figure 12.3). This suggests the value of incorporating both aerobic and anaerobic activities when the goal is to improve body image. In their review, they included studies looking at female-only samples (48%), male and female samples (39%), and male-only samples (10%). Given that they had heterogeneity in the sex makeup of the samples, they also looked at sex as a moderator. Larger effects were evident for women compared to men for both the intervention studies (women: ES = 0.43; men: ES = 0.39) and the single-group studies (women: ES = 0.45; men: ES = 0.26). Because evidence generally shows that women have worse body image than men, this might indicate that women have more room to demonstrate improvement.
In 2017, Bassett-Gunter and colleagues (2017) conducted a meta-analysis focused on the effects of exercise for body image concerns expressed by boys and men and used a similar approach to that taken by Hausenblas and Fallon (2006). This allows for direct comparisons of the findings between the previous review focused on men and women. The overall effect size across the 36 studies reviewed was moderate to large (ES = 0.57), with the largest effects observed for correlational studies (ES = 0.66) and controlled trials (ES = 0.65) and much smaller effects for single-group studies (ES = 0.28). These large effects for correlational studies are consistent with the findings of Hausenblas and Fallon (2006), but the effect sizes for the intervention studies are dramatically larger in this review. This overall effect size suggests that larger effects are possible for boys and men than previously reported. This provides an important addition to our understanding by showing the value of physical activity interventions for improving body image in boys and men. In this review, the moderator of exercise mode also was examined, with results showing the largest benefits for aerobic exercise (ES = 0.61) followed by anaerobic exercise (ES = 0.45) and then the combined programs (ES = 0.11). This finding for the combined programs should be considered tenuous because this level of the moderator variable had only two effect sizes. Nonetheless, these findings suggest that for male-only samples, single exercise mode programs yield moderate to large benefits.
Reel and associates (2007) included 35 studies using a variety of experimental designs and reported a moderate beneficial effect of exercise on body image (ES = 0.45) with no difference in effect size based on study design. An interesting finding from this review is that larger benefits were observed in studies that used single-sex samples (ES = 0.50) compared to mixed-sex samples (ES = 0.17). This might relate to issues of SPA that arise when exercising in groups that allow for men and women to perceive that they might be evaluated by members of the opposite sex.
Alleva and colleagues (2015) conducted a meta-analytic review in which they tested the effects of various forms of interventions on body image. They included cognitive behavioral techniques, fitness training programs, media literacy interventions, self-esteem enhancement approaches, and psychoeducation aimed at teaching about the causes and consequences of negative body image. Relevant to our interest in whether exercise is effective in enhancing body image, these authors reported that across all of these interventions, the average effect size across 62 interventions was 0.38. Unfortunately, the authors did not test the particular intervention category as a moderator, so we don’t know how effects compare between these various approaches.
Evidence Specific to the Anticipated Effects of Exercise on Disordered Eating
As previously explained, some evidence supports a link between body image and disordered eating such that better body image is associated with less disordered eating. Additionally, evidence shows that participation in exercise improves body image. The implication, then, is that exercise might have the potential to reduce disordered eating through its positive effect on body image.
That said, concern has been expressed over the possibility that when performed excessively, exercise might lead to disordered eating or even eating disorders. This concern is particularly relevant when one considers the sports for which the pressure for leanness is likely to contribute to unhealthy eating practices. Three primary groups of sports emphasize leanness. Aesthetic sports are those in which performance is evaluated by judges and appearance is a factor in their judgments. These sports include figure skating, dance, gymnastics, and diving. Endurance sports are ones that have an expectation that a leaner build is necessary to be competitive. These sports include cross country running, track, rowing, cycling, and swimming. Finally, a group of sports use weight classes (weight class sports) to ensure that groups of athletes are competitive with size essentially controlled. These sports include wrestling, judo, and weightlifting. For athletes in these sports, exercise sometimes might be used as a way to control weight in an inappropriate way. Mancine, Gusfa, Moshrefi, and Kennedy (2020) conducted a systematic review of this literature and found that six of seven studies observed statistically significant differences between disordered eating rates in lean sports and nonlean sports. The authors concluded that health care professionals should be aware of this risk to allow for early intervention for patients with disordered eating to help prevent the progression to an eating disorder.
The question then becomes if participation in these sports has an impact on body image that manifests in the form of disordered eating or if this behavior is more related to the pressures previously identified (i.e., the pressures associated with sport performance) than to body image. Although no study has looked at this directly, Hausenblas and Downs (2001) conducted a meta-analysis specifically comparing body image between athletes and nonathletes. Clearly, this is not a perfect way to address this question because of the cross-sectional design of the studies, but the findings from this review do indirectly address the question of whether exercise participation conveys a positive effect on body image or if the pressures of sport participation result in the athlete’s exercise failing to protect them from those influences. Given the nature of the research question, it is not surprising that the vast majority of the 74 studies in the review were correlational (95%). Overall, their results showed that athletes had a more positive body image than did nonathletes (ES = 0.27). Their results showed no difference between effects observed for aesthetic sports, endurance sports, or ball sports. However, the level of significance was very close (p [less than] 0.07 instead of the required p [less than] 0.05), and the trend in these findings showed that differences were smaller between athletes and nonathletes for aesthetic sports (ES = 0.23) than for endurance sports (ES = 0.43) or ball sports (ES = 0.40). This might suggest that the benefits of exercise for body image are reduced in the aesthetic sports that emphasize leanness. Further research will be needed to see if this is a reliable difference and to understand better the implications for using exercise as a means of improving body image.
The Risks of Rapid Weight Loss
In 1997 University of Michigan wrestler Jeff Reese died while attempting to make a weight class for an upcoming wrestling competition. To lose 17 pounds (8 kg) as quickly as possible, he was exercising in a rubber suit in a room that was 92 ºF (33 ºC). He died of kidney failure and heart malfunction, which occurred in response to severe dehydration. That year in a 6-week period, two other collegiate wrestlers, who were trying to make weight for a competition over a short period of time, also died. With Jeff Reese’s father and others advocating for change, the NCAA Wrestling Committee quickly made significant rule changes in an attempt to keep athletes safe. In particular, the use of rubber suits, diuretics, and hot rooms (over 79 °F [26 ºC] ) was forbidden. Weigh-ins were conducted 2 hours before a match rather than the night before. This rule was expected to be effective because rapid weight-loss techniques are known to reduce strength, so athletes would not subject their body to this with weigh-ins so close to the time of competition. Weight classes were established at the beginning of the season, and athletes were limited in how much weight they could lose per week. Finally, a hydration status test became required before the start of the season. Although these changes had a positive effect on athletes’ behaviors, 28 deaths of high school wrestlers and 7 deaths of collegiate wrestlers occurred between 1983 and 2018 that could be linked to dehydration. More recently, before the start of the 2017-2018 season, the NCAA implemented stiffer penalties for violations of these rules, which are hoped to further decrease the number of tragic deaths (Zuke, 2018).