Exercise and Mood

Most people who exercise on a regular basis soon begin to notice that if they miss a day or two, it will quickly have an effect on their mood and motivation. There’s recently even been some research to confirm it. Many years ago it was shown that one of the mechanisms for the “Runner’s high,” was the production of endorphins and we now have a great deal of research that is revealing the fundamental mechanisms linking exercise and mood.

Though the link between exercise and mood has been recognized for decades, in the last few years we have seen an increasing body of evidence that exercise can have a useful effect on people with mood disorders. The evidence is extensive (For example: 1. 2. 3.) and is now so strong that many clinicians – and certainly all practitioners of Integrated Medicine – routinely recommend physical exercise as part of a package of health care. There is particularly good evidence that exercise will help with some of the less common types of depression. An exercise program may particularly benefit women with progesterone-related premenstrual mood disturbances.

We now have some good evidence about the mechanisms by which exercise can improve mood. Researchers in China did some experimental work in rats with what they called “Chronic unpredictable stress.” It is just what it sounds like. If the little critters keep getting stressed, they develop many of the signs of depression: they show loss of appetite, social withdrawal and a reduction in exploratory behavior. We could say that the repeated stress reduces their resilience. Chronic stress causes dysfunction in the hormonal system that links the hypothalamus and pituitary glands at the base of the brain, with the adrenal glands that are perched atop the kidneys.

The researchers then gave some of the rats the opportunity to exercise on a wheel. The exercising rats had an increase in the amount of a growth factor called brain-derived neurotrophic factor (BDNF) in a key region of the brain called the hippocampus. In the non-exercisers, the levels of the growth factor went down as they experienced more and more stress. Exercise also smoothed out stress-induced rises in the hormone cortisol.

This is particularly interesting because previous research had shown us that exercise can increase BDNF levels in the brains of stressed and unstressed animals. We also know that if an antidepressant is going to work, it has to be able to stimulate the production of BDNF in the hippocampus of the brain.

One thing that has not been much studied is the impact of exercise on sleep architecture. Most exercisers know that a good workout, run or hike can make you sleep like a log. And there is increasing evidence that correcting sleep disturbances can be a most effective way of improving mood. So much so that many of us now believe the sleep disturbances underlie many mood disorders, rather than sleep disturbances being symptoms of sleep disorder.

My conclusion from reading the literature and working with countless individuals is that unless there is a medical contraindication, a combination or weight training and aerobic exercise should be part of the treatment program for anyone with depression. The biggest problem is motivating someone with depression t do something like exercise. Sometimes it is necessary to wait until the primary treatment has taken hold. Though we have often had a great deal of success by using some of the motivational systems that I’ve described in Healing, Meaning and Purpose.