"Regular exercise httptime.comcollectionguidetoexercise may prevent many cases of future depression according to a new Australian study and researchers say that as little as one hour a week can make a real difference. The paper published in the American Journal of Psychiatry httpajp.psychiatryonline.orgdoiabs.appi.ajp.. followed more than  healthy Norwegian adults without symptoms of anxiety httptime.commagazineusnovemberthvolnous or depression for an average of  years asking them about their exercise habits and symptoms of depression and anxiety at the beginning and end of the study. At the start about  said they didnt exercise and the rest said they exercised anywhere from up to  minutes to more than  hours a week. Over the next decade about  of people in the study developed depression and about  developed anxiety. No relationship was observed between exercise and later anxiety but the researchers did find a link between exercise and later depression. People who said they didnt exercise at the studys start were  more likely to become depressed compared to those who exercised at least  to  hours a week. For people who worked out more no additional benefits were observed. The study could not prove a causeandeffect relationship between exercise and the risk of depression but the authors say it strongly suggests oneespecially because they controlled for other potential factors including age gender social support smoking drinking and body mass index. If their hypothesis is right they say  of depression cases could be prevented if everyone got just one hour of exercise a week. That exercise doesnt have to be intense either they say. People seemed to have mental health benefits from physical activity regardless of whether they reported working out to the point of exhaustion or barely breaking a sweat. MORE  Surprising Benefits of Exercise httptime.comexercisefitnessworkouts Given that the intensity of exercise does not appear to be important the authors wrote in their paper it may be that the most effective public health measures are those that encourage and facilitate increased levels of everyday activities such as walking or cycling. Of course there are other benefits to more frequent and more intense bouts of exercise. Both the American Heart Association and the World Health Organization recommend getting at least  minutes of moderate to highintensity physical activity a week for cardiovascular and overall health. But when it comes to mental health benefits the majority of the protective effect comes from the first one or two hours of exercise each week said study author Samuel Harvey associate professor of workplace mental health at the Black Dog Institute and the University of New South Wales in an email. MORE A New Hope For Depression httptime.comnewhopefordepression The authors write that the combined physical and social benefits of exercise are likely responsible for its ability to help stave off depression. Its also possible they add that exercise may trigger changes in selfesteem the release of moodboosting endorphins and the production of certain proteins. There is good evidence that physical activity can help people recover from depression though we recommend it be used in addition to the usual treatments we would prescribe for established depression like medication and counseling says Harvey. Our study takes this a bit further and shows that exercise may also have a role in preventing people developing depression in the first place."