It is estimated that in the United States
approximately 7.3% of the adult population has an anxiety disorder that
necessitates some form of treatment (Regier et al., 1988). In addition,
stress-related emotions, such as anxiety, are common among healthy
individuals (Cohen, Tyrell, & Smith, 1991). The current interest in
prevention has heightened interest in exercise as an alternative or
adjunct to traditional interventions such as psychotherapy or drug
therapies.
Anxiety is associated with the emergence of a negative form of cognitive appraisal typified by worry, self-doubt, and apprehension. According to Lazarus and Cohen (1977), it usually arises “...in the face of demands that tax or exceed the resources of the system or ... demands to which there are no readily available or automatic adaptive responses” (p. 109). Anxiety is a cognitive phenomenon and is usually measured by questionnaire instruments. These questionnaires are sometimes accompanied by physiological measures that are associated with heightened arousal/anxiety (e.g., heart rate, blood pressure, skin conductance, muscle tension). A common distinction in this literature is between state and trait questionnaire measures of anxiety. Trait anxiety is the general predisposition to respond across many situations with high levels of anxiety. State anxiety, on the other hand, is much more specific and refers to the person’s anxiety at a particular moment. Although “trait” and “state” aspects of anxiety are conceptually distinct, the available operational measures show a considerable amount of overlap among these subcomponents of anxiety (Smith, 1989).
For meta-analytic reviews of this topic, the inclusion criterion has been that only studies examining anxiety measures before and after either acute or chronic exercise have been included in the review. Studies with experiment-imposed psychosocial stressors during the postexercise period have not been included since this would confound the effects of exercise with the effects of stressors (e.g., Stoop color-word test, active physical performance). The meta-analysis by Schlicht (1994), however, included some stress-reactivity studies and therefore was not interpretable.
Landers and Petruzzello (1994) examined the results of 27 narrative reviews that had been conducted between 1960 and 1991 and found that in 81% of them the authors had concluded that physical activity/fitness was related to anxiety reduction following exercise and there was little or no conflicting data presented in these reviews. For the other 19%, the authors had concluded that most of the findings were supportive of exercise being related to a reduction in anxiety, but there were some divergent results. None of these narrative reviews concluded that there was no relationship.
There have been six meta-analyses examining the relationship between exercise and anxiety reduction (Calfas & Taylor, 1994; Kugler, Seelback, & Krüskemper, 1994; Landers & Petruzzello, 1994; Long & van Stavel, 1995; McDonald & Hodgdon, 1991; Petruzzello, Landers, Hatfield, Kubitz, & Salazar, 1991). These meta-analyses ranged from 159 studies (Landers & Petruzzello, 1994; Petruzzello et al., 1991) to five studies (Calfas & Taylor, 1994) reviewed. All six of these meta-analyses found that across all studies examined, exercise was significantly related to a reduction in anxiety. These effects ranged from “small” to “moderate” in size and were consistent for trait, state, and psychophysiological measures of anxiety. The vast majority of the narrative reviews and all of the meta-analytic reviews support the conclusion that across studies published between 1960 and 1995 there is a small to moderate relationship showing that both acute and chronic exercise reduces anxiety. This reduction occurs for all types of subjects, regardless of the measures of anxiety being employed (i.e., state, trait or psychophysiological), the intensity or the duration of the exercise, the type of exercise paradigm (i.e., acute or chronic), and the scientific quality of the studies. Another meta-analysis (Kelley & Tran, 1995) of 35 clinical trial studies involving 1,076 subjects has confirmed the psychophysiological findings in showing small (–4/–3 mm Hg), but statistically significant, postexercise reductions for both systolic and diastolic blood pressure among normal normotensive adults.
In addition to these general effects, some of these meta-analyses (Landers & Petruzzello, 1994; Petruzzello et al., 1991) that examined more studies and therefore had more findings to consider were able to identify several variables that moderated the relationship between exercise and anxiety reduction. Compared to the overall conclusion noted above, which is based on hundreds of studies involving thousands of subjects, the findings for the moderating variables are based on a much smaller database. More research, therefore, is warranted to examine further the conclusions derived from the following moderating variables. The meta-analyses show that the larger effects of exercise on anxiety reduction are shown when: (a) the exercise is “aerobic” (e.g., running, swimming, cycling) as opposed to nonaerobic (e.g., handball, strength-flexibility training), (b) the length of the aerobic training program is at least 10 weeks and preferably greater than 15 weeks, and (c) subjects have initially lower levels of fitness or higher levels of anxiety. The “higher levels of anxiety” includes coronary (Kugler et al., 1994) and panic disorder patients (Meyer, Broocks, Hillmer-Vogel, Bandelow, & Rüther, 1997). In addition, there is limited evidence which suggests that the anxiety reduction is not an artifact “due more to the cessation of a potentially threatening activity than to the exercise itself” (Petruzzello, 1995, p. 109), and the time course for postexercise anxiety reduction is somewhere between four to six hours before anxiety returns to pre-exercise levels (Landers & Petruzzello, 1994). It also appears that although exercise differs from no treatment control groups, it is usually not shown to differ from other known anxiety-reducing treatments (e.g., relaxation training). The finding that exercise can produce an anxiety reduction similar in magnitude to other commonly employed anxiety treatments is noteworthy since exercise can be considered at least as good as these techniques, but in addition, it has many other physical benefits.
Anxiety is associated with the emergence of a negative form of cognitive appraisal typified by worry, self-doubt, and apprehension. According to Lazarus and Cohen (1977), it usually arises “...in the face of demands that tax or exceed the resources of the system or ... demands to which there are no readily available or automatic adaptive responses” (p. 109). Anxiety is a cognitive phenomenon and is usually measured by questionnaire instruments. These questionnaires are sometimes accompanied by physiological measures that are associated with heightened arousal/anxiety (e.g., heart rate, blood pressure, skin conductance, muscle tension). A common distinction in this literature is between state and trait questionnaire measures of anxiety. Trait anxiety is the general predisposition to respond across many situations with high levels of anxiety. State anxiety, on the other hand, is much more specific and refers to the person’s anxiety at a particular moment. Although “trait” and “state” aspects of anxiety are conceptually distinct, the available operational measures show a considerable amount of overlap among these subcomponents of anxiety (Smith, 1989).
For meta-analytic reviews of this topic, the inclusion criterion has been that only studies examining anxiety measures before and after either acute or chronic exercise have been included in the review. Studies with experiment-imposed psychosocial stressors during the postexercise period have not been included since this would confound the effects of exercise with the effects of stressors (e.g., Stoop color-word test, active physical performance). The meta-analysis by Schlicht (1994), however, included some stress-reactivity studies and therefore was not interpretable.
Landers and Petruzzello (1994) examined the results of 27 narrative reviews that had been conducted between 1960 and 1991 and found that in 81% of them the authors had concluded that physical activity/fitness was related to anxiety reduction following exercise and there was little or no conflicting data presented in these reviews. For the other 19%, the authors had concluded that most of the findings were supportive of exercise being related to a reduction in anxiety, but there were some divergent results. None of these narrative reviews concluded that there was no relationship.
There have been six meta-analyses examining the relationship between exercise and anxiety reduction (Calfas & Taylor, 1994; Kugler, Seelback, & Krüskemper, 1994; Landers & Petruzzello, 1994; Long & van Stavel, 1995; McDonald & Hodgdon, 1991; Petruzzello, Landers, Hatfield, Kubitz, & Salazar, 1991). These meta-analyses ranged from 159 studies (Landers & Petruzzello, 1994; Petruzzello et al., 1991) to five studies (Calfas & Taylor, 1994) reviewed. All six of these meta-analyses found that across all studies examined, exercise was significantly related to a reduction in anxiety. These effects ranged from “small” to “moderate” in size and were consistent for trait, state, and psychophysiological measures of anxiety. The vast majority of the narrative reviews and all of the meta-analytic reviews support the conclusion that across studies published between 1960 and 1995 there is a small to moderate relationship showing that both acute and chronic exercise reduces anxiety. This reduction occurs for all types of subjects, regardless of the measures of anxiety being employed (i.e., state, trait or psychophysiological), the intensity or the duration of the exercise, the type of exercise paradigm (i.e., acute or chronic), and the scientific quality of the studies. Another meta-analysis (Kelley & Tran, 1995) of 35 clinical trial studies involving 1,076 subjects has confirmed the psychophysiological findings in showing small (–4/–3 mm Hg), but statistically significant, postexercise reductions for both systolic and diastolic blood pressure among normal normotensive adults.
In addition to these general effects, some of these meta-analyses (Landers & Petruzzello, 1994; Petruzzello et al., 1991) that examined more studies and therefore had more findings to consider were able to identify several variables that moderated the relationship between exercise and anxiety reduction. Compared to the overall conclusion noted above, which is based on hundreds of studies involving thousands of subjects, the findings for the moderating variables are based on a much smaller database. More research, therefore, is warranted to examine further the conclusions derived from the following moderating variables. The meta-analyses show that the larger effects of exercise on anxiety reduction are shown when: (a) the exercise is “aerobic” (e.g., running, swimming, cycling) as opposed to nonaerobic (e.g., handball, strength-flexibility training), (b) the length of the aerobic training program is at least 10 weeks and preferably greater than 15 weeks, and (c) subjects have initially lower levels of fitness or higher levels of anxiety. The “higher levels of anxiety” includes coronary (Kugler et al., 1994) and panic disorder patients (Meyer, Broocks, Hillmer-Vogel, Bandelow, & Rüther, 1997). In addition, there is limited evidence which suggests that the anxiety reduction is not an artifact “due more to the cessation of a potentially threatening activity than to the exercise itself” (Petruzzello, 1995, p. 109), and the time course for postexercise anxiety reduction is somewhere between four to six hours before anxiety returns to pre-exercise levels (Landers & Petruzzello, 1994). It also appears that although exercise differs from no treatment control groups, it is usually not shown to differ from other known anxiety-reducing treatments (e.g., relaxation training). The finding that exercise can produce an anxiety reduction similar in magnitude to other commonly employed anxiety treatments is noteworthy since exercise can be considered at least as good as these techniques, but in addition, it has many other physical benefits.
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