The well-known recommendation to exercise in order to relieve and/or improve a wide variety of health problems may sometimes seem exaggerated. One might ask whether going to the gym or chopping wood will truly improve sleep, cognition, fragile bones, cholesterol levels, high blood pressure, and obesity, as well as decrease vulnerability to diabetes, heart disease, and cancer. That is an awful lot to ask of a daily bout of physical activity.
However, many studies over the past several decades have confirmed the positive relationship between exercise and an array of health effects. Exercise is not going to prevent anyone from eventually exiting this world, but engaging in physical activity may make us more healthy while we are still in it.
Studies over the past decade on exercise and mental disorders have added another benefit to consistent physical activity: Depressed patients may benefit as much from routine exercise as they do by taking antidepressants. Craft and Perna published an extensive review of studies on whether or not exercise might have a therapeutic role in clinical depression. The ability of depressed patients to carry out physical work has been shown to be significantly impaired, and they are less fit than the general population, according to some studies cited in the article. It is not hard to find reasons for the diminished physical well-being. Depression is often accompanied by fatigue, social withdrawal, sleep disturbances, and the side effects of antidepressants include dizziness, nausea, and even weight gain. These factors may make engaging in routine physical activity difficult, unless there is outside support to do so.
In a typical study to see whether exercise might be beneficial not just in improving physical status but also in relieving the symptom of depression, the patients are enrolled in an exercise program, walking three or four times a week, for example, or doing resistance training. The severity of their depression is compared with a control group of patients who do not exercise but engage in some other type of intervention so they receive the same amount of care and attention from the research staff. The results have been consistent study after study: Exercise has a positive effect on depression.
In one particularly compelling study, the effect of exercise over 16 weeks was compared with the effect of an antidepressant (sertraline) alone and with sertraline and exercise. About two-thirds of the patients in each group went into remission after the four-month testing period. The results indicate that exercise alone was as effective as the medication alone or medication plus exercise in relieving the depression.
If exercise is treated like any other therapeutic intervention, it is important to determine the most effective dose, timing, and type, as one would with medication. Walking slowly on a treadmill versus jogging or resistance training once a week, or four times a week, are some of the variables that have to be examined. Should the exercise be mild or intense? Is it better to exercise outside in the fresh air and sunlight, or does this make any difference? Might yoga or other group exercise be more beneficial than solitary workouts, or a walk, because they diminish social isolation? Is there some way of identifying patients at the onset of their depression who might benefit from exercise rather than antidepressant therapy? How long should it take for an exercise program to produce a lessening of depressive symptoms? Many antidepressants take several weeks before they seem to have an effect; should the patient wait the same amount of time to see whether exercise relieves symptoms?
These questions can be answered fairly easily with additional studies. What is more difficult is how to translate these findings to the real world. To begin with, who is going to treat the patients? Therapists are rarely, if ever, also trained as exercise physiologists. And exercise physiologists may not have any training or experience working with depressed clients. Do these professionals even communicate with each other? A therapist may be able to refer a patient to a physical therapist for an initial consultation as to what kind of exercise the patient can do without injury or pain, but how should the patient follow up? Where will she exercise? Does he have to join a gym or a local Y to exercise? Who will determine the type of exercise program? What oversight is available to make sure the exercise program is carried out effectively and without injury or pain from overused muscles? Who will help/motivate the depressed patient to participate over several weeks rather than dropping out? And finally, even if exercise can be as effective as medication for depression, who will pay for it? Visits to a psychotherapist and medication may be paid for now in their entirety, or at least in part, by health insurance. Therapeutic visits with an exercise physiologist rather than a prescription for an antidepressant is probably not covered under billing codes for mental illness, and thus may be an out-of-pocket expense.
And yet, exercise should not be overlooked or discarded as an effective way of managing depression. Its value in increasing general health, sleep efficacy, and increased physical fitness, in addition to relieving the symptoms of depression without the side effects of drugs, cannot be overestimated. Now is the time to figure out how to apply this knowledge.
“The Benefits of Exercise for the Clinically Depressed,” Craft L and Perna F, Prim Care Companion J Clin Psychiatry. 2004; 6(3): 104–111.
“Effects of exercise training on older patients with major depression,” Blumenthal JA, Babyak MA, and Moore KA. et al. Arch Intern Med. 1999 159:2349–2356