Depression is a mental disorder that causes low mood, loss of interest in normally pleasurable activities, low self-esteem, fatigue, and physical symptoms. It affects about 10% of all people at one time or another.

In the United States, depression is treated with psychotherapy, medication, and neurostimulation, either alone or in combination. However, treatment for depression is not always successful, and the benefits don't always last.

Some patients may find that medications have unpleasant side effects, or decide to stop taking medication because of cost considerations. Others may find the therapies just don't do enough to make them feel better.

There are a variety of reasons why some patients have trouble with treatment. They may find that medications have unpleasant side effects, decide to stop taking medication because of cost considerations; or they may find the therapies just don't do enough to make them feel better.

Because existing treatments don't help everyone, other approaches are always being explored — either as primary therapies or as combination treatments to enhance the effectiveness of existing options. Physical exercise has been a major area of interest. Tai chi, yoga, herbal and homeopathic remedies are also being studied.

A recent report looked at a large number of studies designed to measure the effectiveness of either aerobic exercise or resistance training programs on depressive symptoms in an effort to offer some recommendations that might give depressed patients another form of treatment.

Tailoring Exercise to Treat Depression
Regular exercise is known to improve self-esteem, self control, and sleep, and help ward off or slow the progression of many chronic medical conditions, particularly those related to being overweight or obese.

Exercise leads to the release of endorphins, body chemicals that reduce the perception of pain and increase the feeling of well-being. Endorphin release is the basis for the idea that exercise has a positive effect on symptoms of depression.

The evidence in favor of exercise as a treatment for depression is compelling, according to this recent review. But what kind of exercise? And how much, how often, and at what intensity is necessary to make a significant difference?

The researchers, from the University of Texas Southwestern Medical Center, found that several studies showed improvements in depressive symptoms and prolonged remission rates in groups who were prescribed aerobic exercise. One study of resistance training showed it significantly reduced depressive symptoms which persisted even after the end of the study period, as the patients continued unsupervised resistance training on their own.

From the available evidence, the researchers developed the guidelines for exercise prescription for alleviation of depression.

What Type of Exercise?
Aerobic exercise had the most evidence demonstrating its benefits, but both aerobic exercise and resistance training appear to help reducing symptoms of depression.

How Often?
The studies reviewed represented a range of exercise schedules — from two to five sessions per week and lasting from between 30 to 60 minutes. The authors recommend regular exercise at least three times a week for 45-60 minutes for the best mood-improving benefits.

How Much?
The intensity of aerobic exercise is usually measured as a percentage of an individual’s maximum heart rate. You should aim to exercise at 50-80% of your heart rate (HR) maximum for aerobic exercise.

Resistance training is usually measured as a percent of the maximum weight that can be lifted, along with the number of sets and repetitions.

The greater the intensity of resistance training, the greater the improvement in depressive symptoms, according to several studies. The researchers suggest that the people with depression perform a variety of upper and lower body resistance exercise, including three sets of eight repetitions.

How Long to See Effects?
Symptoms of depression often ease immediately following periods of aerobic exercise. But for sustained relief from depression, you will need several weeks or months of exercise.

Most of the studies reviewed had treatment periods of at least 10 weeks. While people may feel better after 4 weeks, the authors recommend that they should continue for at least 10-12 weeks to achieve the best results.

Getting Started
When beginning any exercise program, it is important to start gradually and choose a form of exercise you can fit into your life fairly easily. If you are older and not already in good physical shape, you should begin by consulting your physician.

For exercise to be of benefit — for anyone, including people with depression — a person has to find they enjoy doing it enough to stick with it. First decide what type and frequency of physical activity you prefer. The availability of exercise equipment, gyms, and safe areas for exercise will also be a factor. Supportive strategies such as setting personalized goals and working with a trainer or program offering individualized feedback helped people with depression stay with their regimens and reap the most benefits.

Based on the findings of this study, both aerobic exercise and resistance training are effective stand-alone or supplemental treatments for depression. While more research is needed to identify optimum types and duration, popular exercise guidelines based on current research are useful parameters for depressed and non-depressed people.

As with any new medication or therapy, patients being treated for depression should consult with their physicians to be sure it is appropriate for them and that they are physically capable of undertaking a vigorous exercise program. Patients may additionally want to work with a physical therapist or trainer to determine the appropriate heart rate target for aerobic training and weight limits for resistance training.

When beginning an exercise program, it is recommended to start at a lower level and to work up slowly to target goals as strength and endurance improve. Patients with heart disease, arthritis or other limiting conditions should have their programs modified appropriately to get maximum benefit for their mood without worsening other conditions.