This is an excerpt from Clinical Exercise Physiology 5th Edition With HKPropel Access by Jonathan K Ehrman,Paul M. Gordon,Paul S. Visich & Steven J. Keteyian.
An exercise prescription for people with depression will likely differ little from the prescription used for healthy individuals. Clinicians should be aware, however, that several symptoms of depression (e.g., loss of interest, fatigue, low self-confidence) may interfere with participation in exercise, and that comorbidities can further complicate matters.
For individuals whose depression is considered stable enough to begin an exercise program (e.g., they are not suicidal; their depression is not so severe that it prevents active participation), the question arises about how to manage depressive symptoms that may affect the course of participation in exercise. First, recognize that significant comorbidity exists between depression and other chronic diseases; people with depression are unlikely to present with depression alone. Furthermore, depression can affect the course of chronic disease. For example, the presence of depression is associated with more complications and increased mortality in patients with diabetes (25, 50). Evidence also identifies depression as a powerful and independent risk factor for cardiac outcomes in patients with coronary heart disease (such as recurrent myocardial infarction and mortality) (60). For cancer patients, untreated depression has been linked to poorer treatment adherence, increased hospital stays, and mortality (71).
Besides often being present as a comorbidity in patients with another chronic disease, depression is associated with unhealthy lifestyle behaviors such as tobacco and alcohol use (96), poor diet (34), physical inactivity (106), high levels of sedentary behavior (82), and poor sleep (7).
Exercise as a Treatment for Depression
Many systematic reviews and meta-analyses have summarized the antidepressant effect of exercise. A meta-review (a review of published meta-analyses and therefore one of the highest levels of evidence) conducted in 2019 concluded across eight individual meta-analyses that exercise reduced depressive symptoms in children, adults, and older adults (5). For example, a meta-analysis conducted in 2016 by Schuch and colleagues (83) summarized the results of RCTs on exercise therapy for depression. In 25 RCTs comparing exercise versus control groups, exercise had a large and significant effect on depression. Larger effect sizes were found for outpatients, in samples without other comorbidities, and when exercise interventions were supervised by a trained exercise professional. The review found that previous meta-analyses may have underestimated the benefits of exercise because of publication bias and concluded that exercise can be considered an evidence-based treatment for depression.
Despite the strong evidence base, supervised exercise is not incorporated into clinical practice as often as it should be. It is likely that physicians are unaware of the research or are reluctant to overcome the dualistic treatment approach that underpinned their medical training. Even clinical practice guidelines, which are intended to be based off research evidence, are subject to bias and the potential for overtreatment (86). One study evaluated international clinical practice guidelines for the treatment of major depressive disorder, specifically looking at the recommendation of physical activity (45). Seventeen guidelines were included, of which only four recommended physical activity as a frontline intervention; two did not mention physical activity, and eleven made some mention. The American Psychiatric Association Clinical Practice Guidelines, for example (38), did not suggest exercise as an evidence-based treatment modality, stating only that if a client wishes to engage in physical activity there is little to argue against it. These guidelines have been criticized because they contained no systematic review of studies on the effects of exercise (22). Conversely, Canada’s 2016 CANMAT guidelines (74) suggest that exercise should be recommended as first- or second-line treatment for mild to moderate depression.
Preliminary evidence from meta-analyses suggests that the magnitude of benefit associated with exercise training is similar to that of antidepressant medications (21, 56). However, caution should be taken interpreting these comparisons because their samples were small (usually less than N = 300) and fewer than five trials in such analyses were included. Therefore, in summary, the recommendation is that exercise should be prescribed as an add-on treatment to usual care.
A number of reviews have explored the potential mechanisms of the antidepressant effect of exercise (49), although the research is equivocal. The main reason for this uncertainty is the complex etiology of depression. No single abnormality or altered physiological system occurs in people with depression. Therefore it is unlikely that one mechanism is solely responsible for the antidepressant effects of exercise. One proposed mechanism is through the hypothalamic–pituitary–adrenal (HPA) axis. The HPA axis produces cortisol in response to stress, and among people with depression it is common to see hyperactivity in this pathway. Exercise is believed to influence depression through normalization of the HPA axis (112). Another potential mechanism is the reversal of atrophy of the hippocampus (35), which is consistently affected in people with depression (81). Exercise may also improve symptoms of depression by increasing self-esteem and self-efficacy (32). Specifically, people with depression have lower levels of self-esteem (68) and the relationship may be cyclical, whereby low self-esteem can increase depressive symptoms and exacerbate self-esteem deficits. Behavioral activation also occurs with regular exercise, which is an important component of CBT for MDD (80). An example of an exercise prescription for a patient with depression appears in table 34.3. The issue of how much exercise and what type is needed to achieve an antidepressant effect is also an important topic, one that is discussed in practical application 34.4.
Adherence and Exercise
Patients with depression may find it more difficult to stay engaged in an exercise program compared with patients who are not depressed, and specific symptoms of depression such as fatigue and a loss of interest in people and activities may interfere with adherence to an exercise regimen (see practical application 34.5.
O’Neal and colleagues (64) have offered recommendations for working with depressed people in a supervised exercise setting. First, they emphasize that nonadherence should be expected. Exercise professionals should avoid judging or blaming the patient for their depression because doing so will likely lead to guilt and a sense of failure that may cause the person to drop out of the exercise program. Instead, when nonadherence occurs, it should be viewed as a learning opportunity. That is, lapses in exercise participation can be used to identify an individual’s unique barriers to adherence. The exercise professional can then help the patient find ways around these obstacles.
In addition, it is important to adopt a patient-centered approach. This includes helping individuals take personal responsibility for exercise prescription, exercise delivery, and monitoring of compliance. There is no one-size-fits-all prescription for physical activity, and the exercise professional should focus on improving self-efficacy, autonomy, and intrinsic motivation. Finally, when working in exercise settings, it is important to be familiar with the symptoms of depression and have some knowledge of treatment options. When depression is identified, the exercise professional should express warmth and empathy toward the patient while taking care to maintain an appropriate clinician–client boundary. Specifically, the exercise professional should not attempt to be the patient’s psychotherapist but should instead have referral sources available.
Practical Application 34.5
Strategies for Improving Exercise Adherence in Patients With Depression
- Most importantly, work to establish good rapport with patients. Positive feedback and empathy from exercise staff can go a long way toward promoting adherence. Encourage the patient and celebrate progress, even if it is small.
- At the initiation of an exercise program, review with patients their unique barriers to participation (e.g., work responsibilities, family issues). These barriers should then be discussed with patients to find ways to overcome or minimize them.
- Educate patients about the benefits of exercise for physical health and depression. Elicit from patients other benefits of exercise specific to them and periodically remind them of those benefits.
- Patients are more likely to adhere to exercise training if the experience is enjoyable. Work with patients to increase their satisfaction with the program (e.g., switching equipment used, varying location and the time of day). Their programs should be based on their current preferences and expectations, taking into account their initial fitness levels and ratings of perceived exertion during exercise.
- Help patients develop realistic exercise goals (e.g., gradual increase in number of exercise sessions per week). If they are new to exercise, consider open-ended goals (e.g., to increase their daily step count or to break up sitting time). Discuss problem solving around barriers, and encourage modification of goals as needed. Design a plan for when relapses occur.
- Be prepared to identify changes in mood and modify the session accordingly. If a patient is experiencing significant fatigue, low mood, or side effects from their psychotropic medications, this should be taken into consideration.
- Emphasize the short-term benefits, even after a single session, such as reduced stress, increased energy, and distraction from negative thoughts. Many patients are focused on long-term goals such as weight loss or improved self-esteem, so emphasizing short-term benefits can increase adherence.
- Encourage patients to reward themselves for participation in exercise. Emphasize the importance of positive reinforcement for accomplishments. Even simple rewards (e.g., a new book, a pleasant dinner out) can be powerful motivators.
- Recommend to patients that they talk to family members and friends about their exercise program and goals. Such people are often a valuable resource for offering encouragement in support of the patients’ participation in exercise.
- Remember that untreated or undertreated depression is likely to have a negative effect on adherence to exercise. Encourage patients to seek treatment for depression if symptoms appear to interfere with exercise participation.