An analysis of 14 years of published studies concludes that exercise can lower the anxiety people feel when they have to live with a chronic illness. But there is no reason why the findings should not also apply to people anxious for other reasons.

Psychological problems like Anxiety can make a patient less likely to stick to their prescribed treatment. And of course, anxiety doesn't improve the quality of a patient's life. Calmer is better.

Having an illness that will be with you for years to come is bad enough. The anxiety that goes along with the illness can make matters even worse. Doctors sometimes ignore the psychological aspects of living with a condition like heart disease and focus solely on the physical necessities of treating the condition. But even from this narrow viewpoint, psychological problems like anxiety can make a patient less likely to stick to their prescribed treatment. And of course, anxiety doesn't improve the quality of a patient's life. Calmer is better.

Anti−anxiety drugs can sometimes help, but maybe there's a better way.

Some studies have shown that exercise can lower the anxiety that accompanies illness. A team at the University of Georgia analyzed the results of 40 separate studies published between 1995 and 2008. They found that patients who participated in an exercise program were significantly less anxious afterwards. The decrease in anxiety was larger than that shown in the same time span by patients who didn't take part in an exercise program.

The 40 studies looked at people with illnesses ranging from arthritis to cancer. The subjects in these studies were initially sedentary (not exercising). In all of the studies, anxiety was compared both before and after participating in an exercise program and between people who exercised and those who did not. Exercise programs varied widely in type of exercise and in the length of the program. The average exercise program lasted 16 weeks and consisted of three, 42 minute sessions weekly—about two hours of exercise a week. The average age of the subjects was 50.

Overall, exercise programs lasting 3−12 weeks worked better than longer programs did. The researchers suggest this is because participants were more likely to stick with the shorter programs. And exercise programs with sessions longer than 30 minutes worked better than those with sessions under 30 minutes. The only illness tested where exercise wasn't effective at lowering anxiety was multiple sclerosis.

Anxiety was measured by different questionnaires (scales) in different studies. In some studies, participants were asked to rate their current anxiety, while other studies went back a week or more. All of this makes interpreting the size of the effect of exercise on anxiety a bit tricky. The researchers say the average amount exercise lowered anxiety was similar to the amount it's been shown to lower fatigue in other studies.

While the analysis only looked at studies where people participated in a fixed exercise program, there's no reason to think that random bits of walking, softball, aerobics or working out with weights wouldn't also do the trick.

The study was published in the February 22, 2010 issue of Archives of Internal Medicine.