Even small doses of physical activity fight depression: Study

Even small doses of physical activity, such as brisk walking, may substantially lower the risk of depression, according to a new data analysis.

"Most benefits are realized when moving from no activity to at least some," the study authors wrote.

Recommended levels of exercise in the United States, according to the US Centers for Disease Control and Prevention, include aerobic activity at moderate levels (such as a brisk walk) for 2.5 hours a week, along with a workout of all major muscle groups twice a week.

Alternatively, a person can choose a vigorous aerobic exercise, such as running, for 1.25 hours each week, along with the same amount of strength training.

Moderate to vigorous exercise is good for us, according to the CDC. It improves sleep; lowers blood pressure; protects against heart disease, diabetes and cancer; reduces stress; boosts mood; and fights anxiety and depression.

But in today's busy world, many people find it difficult to fit in a jog or a visit to the gym. Add depression to the mix, and the motivation for exercise drops even further, experts say.

Every little bit helps

The meta-analysis, published Wednesday in the journal JAMA Psychiatry, looked at 15 studies involving over 190,000 people to determine how much exercise was needed to reduce depression.

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, the study said.

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.

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