Run, skip, hop, jump or just walk to lift those blues

Researchers at the University of Texas at Austin say a single 30-minute walk on a treadmill can give a temporary emotional lift to patients diagnosed with major depressive disorder.

In a comparatively small study it is suggested that exercise could offer depressed patients a way to give themselves an emotional boost.

The researchers found that among 40 men and women recently diagnosed with major depression, those who spent just a half hour on a treadmill reported a short-term improvement in energy and emotional well-being.

They say though a single workout is not the answer to clinical depression, it might help patients to manage their symptoms on a daily basis.

Dr. John Bartholomew, the study's lead author says previous studies have shown that regular exercise can help treat depression over time, but he says the new findings show that good results can be seen immediately and patients do not have to wait in order to feel some benefit.

Numerous studies have shown that active adults are less likely to suffer depression than their sedentary peers, and in fact regular exercise can serve as a therapy for the disorder and perhaps is as effective as antidepressant drugs in some cases.

But to date the immediate effects of exercise on depressed individuals have been unclear.

In the current study patients were randomly assigned to walk on a treadmill for 30 minutes or spend the time resting quietly in a comfortable chair.

All completed standard surveys of mood and well-being before and after their exercise or rest period.

The researchers found that while both exercise and quiet rest appeared to boost patients' mood, and helped them feel less fatigue, tension, distress and anger, the exercisers reported greater gains in general well-being and "vigor".

According to Bartholomew, the quiet-rest group possibly felt better just because they were getting out of the house and interacting with others.

People with depression, he says, often isolate themselves and avoid social situations, which can in turn feed the depression.

Experts have often suggested that exercise helps depression, as physical activity appears to affect some key nervous system chemicals - norepinephrine and serotonin - that are targets of antidepressant drugs, as well as brain neurotrophins, which help protect nerve cells from injury and transmit nerve signals in brain regions related to mood.

But Bartholomew believes there are also "cognitive" effects at work.

He says the exercisers in this study, may well have felt a "sense of accomplishment" that lifted their general mood.

One of the challenges, says Bartholomew, in using exercise as depression therapy is that the condition makes it hard for people to find the motivation to be active, but if they can get outside for even a short walk, it could help in managing the daily symptoms of the disorder.

The findings were published in the journal Medicine & Science, December 2005.