Exercise as it relates to specific conditions

Dementia

• Physical activity, it has been shown, is inversely associated with cognitive decline. Case-control studies tend to show a slight beneficial influence of physical activity against Alzheimer’s disease. Prospective analyses (similar to longitudinal studies) tend to show a more convincing protective effect of physical activity against Alzheimer’s as well as against all forms of dementia combined. No evidence of harmful effects from physical activity or exercise (including vigorous exercise) is evident (Laurin et al., 2005).

Depression, anxiety and stress

• Physical activity has been found to improve mental health conditions, particularly anxiety, depression and general well-being (Schmitz et al., 2004).
• Exercise has a low-to-moderate effect in reducing anxiety. Exercise training can reduce trait anxiety; single exercise sessions can reduce state anxiety. Single sessions of moderate exercise can reduce short-term physiological reactivity to brief psychosocial stressors and enhance recovery (Taylor, 2000). The strongest anxiety-reduction effects are shown in randomized controlled trials.
• Exercise decreases depression. Epidemiological evidence shows that physical activity is associated with a decreased risk of developing clinically defined depression. Experimental studies have shown that aerobic and resistance exercise may be used to treat moderate and more severe depression, usually as an adjunct to standard treatment. The anti-depressant effect of exercise can be of the same magnitude as that found for other psychotherapeutic interventions. No negative effects of exercise have been noted in depressed populations (Mutrie, 2000).
• Persons who have experienced coronary heart failure (CHF) undergo a dramatic reduction in their quality of life, which commonly causes them anxiety and depression. Clinical trials involving these patients have observed marked improvements in exercise capacity. The evidence suggests that exercise can play an important role in improving function and quality of life of patients with CHF (Lloyd-Williams & Mair, 2005).
• Aerobic exercise training has anxiolytic and antidepressant effects (Salmon, 2000).
• Habitual exercise in adolescents correlates with low depression scores (Norris et. al., 1992). A study of 16,483 university undergraduates likewise found that exercise correlated with lower levels of depression (Steptoe et al., 1997).
• In a general population sample of 55,000 a self-reported correlation between recreational physical activity and better mental health was found, including fewer symptoms of depression and anxiety (Stephens, 1988).
• Aerobic activity shown to specifically reduce depression in two well-controlled studies of 10–11 weeks of walking and running in two populations selected for exposure to stress or high anxiety (Steptoe et al., 1989; Roth et al., 1987, as cited in Salmon, 2000).
• Exercise training (in comparison to strength and flexibility training) reduced anxious mood in subjects with high anxiety. Follow-up revealed that the effect persisted over three months (Steptoe et al., 1989).
• Symptoms of anxiety and depression gradually increased over the two weeks after the cessation of regular running (Morris et al., 1990).
• Exercise therapy is significantly associated with therapeutic benefit among people with major depressive disorder, particularly if it is continued over time. It may in fact be at least as effective as standard pharmacotherapy. Participants in the exercise group were less likely to relapse then those in other groups receiving medication. Each 50-minute increment of exercise per week was associated with a 50% decrease in the risk of being classified as depressed (Babyak et al., 2000).
• Regular aerobic exercise alone is associated with clinical improvement in patients suffering from panic disorder, but one that is less than treatment with clomipramine. Depressive symptoms were also improved by exercise and clomipramine treatment (Broocks et al., 1998).
• Regular exercise can have positive effects on psychopathologic outcomes (i.e., anxiety, depression and self-esteem) in adult and non-obese child populations (N. Mutrie, 1998, and A. Steptoe, 1996, as cited in Daley et al., 2006). Obese adolescent girls who participated in aerobic exercise have lower depression scores then girls allocated to other types of exercise or to usual care (S. G. Stella, 2005, as cited in Daley et al., 2006).
• Physical activity was associated with a decreased likelihood of depression in a survey of 9,938 school-age children. Male youths were more likely to participate in physical activity and less likely to feel depressed (Goodwin, 2006).
• In a population sample of 19,288 adolescent and adult twins and their families, exercisers were found on average to be less anxious, depressed and neurotic (DeMoor et al., 2006).
• Sufficient evidence has been found for the effectiveness of exercise in the treatment of clinical depression. Exercise has a moderate reducing effect on state and trait anxiety. Aerobic and resistance exercise enhance mood states (Fox, 1999).
• Aerobic exercise training protects against the emotional and physiological consequences of stress (Salmon, 2000).
• Balance of evidence suggests that sensitivity to stress is reduced after exercise training (Salmon, 2000).
• The negative impact of life events was significantly lower among students who exercised regularly than among those who rarely exercised (Brown & Lawton, 1986).
• Adolescents who reported exercising more also self-reported less stress and depression. Adolescents in the study who were part of the high-intensity exercise group reported less perceived stress than those groups that participated in moderate-intensity exercise, flexibility training, or no exercise program at all (the control group). In the high-intensity exercise group, the relationship between perceived stress and anxiety and depression was considerably weakened after the exercise program (Norris et al., 1992).

Eating disorders

• Exercise was found to be more effective than cognitive–behavioural therapy (CBT) in reducing drive for thinness, bulimic symptoms (both binge eating and vomiting) and body dissatisfaction among subjects with eating disorders (Sundgot-Borgen et al., 2002).
• Women participating in exercise groups significantly reduced obligatory attitudes toward exercise relative to the comparison group. Moreover, anorexic women in the exercise group gained one-third more weight than those in the comparison group (Calogero & Pedrotty, 2004).
• Studies have found that exercise has a positive effect on the success of cognitive behavioural therapy (Fossati et al., 2004; Pendleton et al., 2002).

Schizophrenia

• The high incidence of obesity and other morbid conditions is strongly related to physical inactivity in this population. Existing research on the psychological benefits of exercise participation has many methodological flaws and tends to be of pre-experimental design. There is tentative evidence that participating in exercise is associated with an alleviation of negative symptoms associated with schizophrenia, such as depression, low self-esteem, and social withdrawal. There is less evidence that exercise may be a useful coping strategy for dealing with positive symptoms, such as auditory hallucinations (Faulkner, 2005).

Drug and alcohol rehabilitation

• When administered as an adjunct in alcohol rehabilitation, exercise regimens definitely have positive effects on aerobic fitness and strength. Evidence for the benefits of exercise during drug rehabilitation is less substantial. In either field of rehabilitation, the links at present between exercise and improved self-esteem, better abstinence, controlled consumption levels, and reductions in anxiety and depression are equivocal (Donaghy & Ussher, 2005).
• Physical exercise was found to be associated with health-related quality of life among persons with anxiety, affective, substance abuse or dependence disorders (Schmitz et al., 2004).