Just an Hour of Weekly Exercise Linked with Less Depression

Exercise has been shown to have many health benefits—both physical and mental.  However, it hasn’t been clear how much weekly activity is needed to reap these benefits.  Now, a new study on weight loss surgery patients showed that even patients who participated in just an hour of moderate-intensity exercise per week experienced less symptoms of depression.  An hour of exercise each week translates to just over 8 minutes per day, on average.  This level of exercise was associated with 92 percent lower odds of treatment for depression or anxiety among adults with severe obesity. Also of note, just 4,750 steps per day, which is less than half of the daily recommendation of 10,000 steps, was associated with reduction in depression or anxiety treatment by 81 percent. According to the study authors, severely obese people are almost twice as likely to have a major depressive disorder (13.3 percent) or anxiety disorder (19.6 percent) when compared to the general population (7.2 and 10.2 percent, respectively).

The study included 850 adults who were seeking weight loss procedures, such as gastric bypass or Lap-band surgery, between 2006 and 2009.  Of the group, a third reported depressive symptoms, while two in five reported taking medication or receiving counseling for depression or anxiety.  The physical activity of the participants was assessed for a week before undergoing weight loss surgery using a small electronic device worn on the ankle. Surveys were also completed to assess mental health functioning, depressive symptoms and treatment for psychiatric and emotional problems.  They found that overall, the more physically active patients were less likely to have depressive symptoms and to have recently received medication or counseling for depression or anxiety than the less active patients.

While the results of the study are provocative, further research is needed to verify that physical activity was responsible for lower levels of depressive symptoms in study group. Since this was an observational, study (meaning patients’ regular physical activity behavior and depressive symptoms were measured at the same time), it could not prove that a patient’s physical activity influenced mental health status.

Another recent study showed that weight loss surgery patients experience an overall improvement in quality of life following surgery, which included a decrease in reported feelings of depression. You can learn about the health, social and mental benefits of surgery here.