Good news for those biking to work, taking the stairs or scheduling evening walks. Even small doses of physical activity — like walking or biking — can help lower your risk of depression, according to new research published in the journal JAMA Psychiatry that looked at data from several previous studies. 

The study analyzed 15 research projects involving over 190,000 people to determine how much exercise would be needed to reduce depression. 

The researchers found that adults who did activities equivalent to 1.25 hours of brisk walking per week had an 18% lower risk of depression compared with those who did not exercise.

Moving up to an "activity volume equivalent to 2.5 hours of brisk walking per week was associated with 25% lower risk of depression," the study authors said.
 

Small changes make a strong difference

Interestingly, the study found the benefits were strongest when a person transitioned from being very inactive to adding minimal movement to their day. "Most benefits are realized when moving from no activity to at least some," the study authors wrote.
 
"Our findings therefore have important new implications for health practitioners making lifestyle recommendations, especially to inactive individuals who may perceive the current recommended target (of exercise) as unrealistic," they added.
 

How much should you exercise?

The U.S. Centers for Disease Control and Prevention recommends moderate levels of weekly exercise for adults (such as a brisk walk) for 2.5 hours a week. 

The CDC notes that in addition to helping alleviate anxiety and depression, moderate to vigorous levels of exercise can:

• lower blood pressure

• protect against heart disease, diabetes and cancer

• reduce stress

• ​boost mood

• ​​improve sleep 

So even if you can’t commit to a regular exercise routine, you may realize some health and mood benefits with small lifestyle changes like taking the stairs, doing exercises at your desk or walking with a friend.

Source: “Association Between Physical Activity and Risk of Depression: A Systematic Review and Meta-analysis,” published online in JAMA Psychiatry, April 13, 2022.