The effects of exercise on body satisfaction and affect

Abstract

This research used ecological momentary assessment to examine the effects of exercise on state body dissatisfaction and affect in 33 undergraduate females with high trait body dissatisfaction and 28 with low trait body dissatisfaction who exercised at least three times weekly. Trait body dissatisfaction was investigated as a moderator of the effects of exercise as well as different motivations for exercise. Results indicated all participants experienced lower state body dissatisfaction and negative affect and greater positive affect post-exercise. Trait body dissatisfaction moderated the association between motivations and exercise effects. Appearance and weight motivations were related to higher state body dissatisfaction for all individuals. Fitness and health motivations were related to higher state body dissatisfaction for high trait body dissatisfied individuals and lower state body dissatisfaction for low trait body dissatisfied individuals. Thus, although exercise has positive effects on body dissatisfaction and affect for high frequency exercisers, their exercise motivations impact these effects.

Introduction

Regular exercise is seen as a positive and necessary addition to an individual's daily activities. The physical benefits of exercise are well established, including reduced risk for cardiovascular disease, certain cancers, and diabetes (U.S. Department of Health and Human Services, 1996). Exercise also has psychological benefits, including greater levels of general well being, greater positive mood, and lower levels of depression and anxiety (Reed and Ones, 2006, Stephens, 1988). These relationships have been shown to be especially strong for women.

While the benefits of exercise are common knowledge, research suggests that among some populations and in some conditions, exercise may be associated with negative consequences. For example, individuals exercising at high levels exhibit greater eating pathology and other related characteristics than individuals who exercise at moderate levels or those who do not exercise at all (Davis et al., 1990, Krejci et al., 1992, Mond et al., 2004). Research by Thome and Espelage (2004) suggests that the presence of maladaptive eating attitudes and behaviors changes the relationship between exercise and affect; exercise was associated with negative affect among those high on maladaptive eating attitudes and with positive affect among those low on maladaptive eating attitudes. In addition, women utilizing exercise as a compensatory behavior report higher levels of body dissatisfaction (LePage, Crowther, Harrington, & Engler, 2008). Given that body dissatisfaction is a major risk factor for eating pathology (e.g., Stice, 2002), it may be that individuals who experience high levels of body dissatisfaction also experience the most negative consequences from their exercise behaviors, while those with low body dissatisfaction experience the more positive effects of exercise.

Body dissatisfaction has been defined as dysfunctional, negative beliefs and feelings about one's weight and shape (Garner, 2002). Research on the relationship between exercise and body dissatisfaction has found that exercise is generally associated with lower levels of body dissatisfaction. In fact, a recent meta-analysis that included single-group studies, correlational studies, and studies containing an experimental and control group (Hausenblas & Fallon, 2006) found that exercise is positively associated with body satisfaction. While correlational studies preclude conclusions regarding causality and laboratory investigations raise concerns about ecological validity, there have been two studies that investigated the immediate impact of exercise on body dissatisfaction in naturalistic exercise settings. One of these studies found that just 60 min of aerobic exercise was associated with significant increases in body satisfaction (McInman & Berger, 1993), while the other found that 30 min of aerobic exercise reduced reported body dissatisfaction, but this effect was not strong enough to withstand the impact of exposure to thin ideal media images (Fallon & Hausenblas, 2005).

In contrast, some research has failed to find positive associations between exercise and body satisfaction. For example, in a correlational study examining a general population of exercisers, Tiggemann and Williamson (2000) found that among young women, exercise frequency was significantly positively associated with body dissatisfaction. Two laboratory studies by Martin Ginis and colleagues (Martin Ginis et al., 2003, Martin Ginis et al., 2008) also have found that exercise is associated with increases in body dissatisfaction. Specifically, Martin Ginis et al. (2008) examined the impact of watching exercise videos on women's body dissatisfaction and found that the greater the perceived discrepancy between the appearance of the exercise participant and the video instructor, the greater the reported body dissatisfaction following exercise. In a second study, Martin Ginis et al. (2003) found that women with greater body image concerns experienced increases in physical appearance anxiety from pre- to post-exercise, suggesting the importance of examining body image disturbance as a potential moderator of the impact of exercise on state body dissatisfaction.

In addition to impacting body dissatisfaction, exercise also has been shown to be associated with positive changes in mood. A recent meta-analysis found overall significant relationships between exercise and improvements in positive affect (Reed & Ones, 2006). Moreover, research by Gauvin, Rejeski, and Norris (1996) that utilized ecological momentary assessment suggests that this positive relationship between exercise and positive affect extends to the naturalistic environment. Their sample of 86 women reported 709 h of physical activity, which was associated with increases in positive engagement, revitalization, tranquility, positive affect, and decreases in negative affect. However, this positive mood enhancement is not found for all people. There is some evidence to suggest that while both moderately and extremely fit people show positive mood increases after exercise, the increases are much larger for the moderately fit individuals (Choi, Van Horn, Picker, & Roberts, 1993).

Focht and Hausenblas, 2001, Focht and Hausenblas, 2003, Focht and Hausenblas, 2006 have conducted a series of studies examining the immediate impact of exercise on affect in various environments. In their first study of 50 young women (Focht & Hausenblas, 2001), they found that aerobic exercise was associated with increases in tranquility, revitalization, and positive engagement and decreases in state anxiety; however, social physique anxiety did not moderate these effects. In subsequent research, Focht and Hausenblas (2006) found that for women with high social physique anxiety, exercising in public settings was associated with negative affective changes, while exercising in private environments was associated with positive affective changes. When women with high social physique anxiety exercised in front of a mirror in a naturalistic exercise setting (Focht & Hausenblas, 2003), they experienced increases in state anxiety during exercise. To the extent that social physique anxiety can be considered a manifestation of body dissatisfaction, these studies suggest the importance of examining body dissatisfaction as a potential moderator of the immediate impact of exercise on affect, particularly in the naturalistic environment.

Motivation for exercise may be an additional moderator of the relationship between exercise and state body dissatisfaction and mood. Research has suggested four motivations for exercise, including appearance related, health, social, and stress management reasons (Cash et al., 1994, Silberstein et al., 1988). Appearance related reasons, e.g., weight control, are more commonly endorsed reasons for exercise for young women than for men (Tiggemann & Williamson, 2000) and are associated with the most negative consequences (Cash et al., 1994, DiBartolo et al., 2007). Individuals who engage in exercise for appearance or weight management reasons report more negative body images regardless of their actual body mass index (BMI). Appearance motivated exercisers also show higher levels of body dissatisfaction (Strelan et al., 2003, Tiggemann and Williamson, 2000), more disregulated eating behaviors (Silberstein et al., 1988), and higher frequencies of exercising (Cash et al., 1994) than individuals who indicate different motivations for exercise. Appearance and weight motivations for exercise have also been shown to be associated with increased levels of depressive symptomatology (DiBartolo et al., 2007).

Fitness and health motivations for exercise have been shown to be related to more positive consequences. Specifically, fitness and health motivations are associated with less body dissatisfaction and eating disturbance and higher self-esteem and psychological well being than other motivations for exercise (DiBartolo et al., 2007, Furnham et al., 2002, McDonald and Thompson, 1992, Strelan et al., 2003, Tiggemann and Williamson, 2000). It may be that discrepancies in the effects of exercise on body dissatisfaction and mood are due to these motivational factors. Raedeke, Focht, and Scales (2007) found that an individual participating in an exercise class whose focus was health oriented reported more positive affect than participants involved in an exercise class whose focus was appearance oriented.

The present study examined the immediate effects of exercise on state body dissatisfaction and positive and negative affect in high frequency female exercisers who were high and low in trait body dissatisfaction. This research also examined whether the association between motivations for exercise and exercise effects were moderated by trait body dissatisfaction. Although there has been research on the effects of exercise in naturalistic exercise settings (e.g., Focht and Hausenblas, 2003, Focht and Hausenblas, 2006), there is very little information on the immediate effects of exercise as it occurs on a day-to-day basis in the naturalistic environment for women who are high and low on trait body dissatisfaction. To address this, this research used ecological momentary assessment, an innovative methodology in which individuals report on their attitudes, emotions, and behaviors as they occur, thus reducing biases related to retrospective recall. Ecological momentary assessment has been shown to be an effective method for collecting data on the impact of naturalistic exercise behavior on affect (e.g., Gauvin et al., 1996). For two weeks, participants reported on their state body dissatisfaction and affect at random times each day and on their exercise behavior and subsequent state body dissatisfaction and affect when exercise occurred.

The following hypotheses were tested. Hypothesis 1: individuals exhibiting high initial trait body dissatisfaction will show greater state body dissatisfaction, less positive affect, and greater negative affect than low trait body dissatisfied individuals at random and fixed assessments. Hypothesis 2: low trait body dissatisfied individuals will exhibit less state body dissatisfaction and negative affect and more positive affect following exercise than at other times throughout the day. High trait body dissatisfied individuals will experience more state body dissatisfaction and negative affect and less positive affect following exercise than at other times throughout the day. Hypothesis 3: as appearance related motivations for exercise increase, state body dissatisfaction and negative affect will increase, while positive affect will decrease; as fitness and health motivations for exercise increase, positive affect will increase while state body dissatisfaction and negative affect will decrease. Hypothesis 4: the effects of exercise motivations will be stronger in highly trait body dissatisfied individuals than in low trait body dissatisfied individuals.