You do not need to hit the gym and lift heavy weights, but small doses of physical activity, such as brisk walking, may substantially help lower the risk of depression, suggests a study.

The study, led by a team of international researchers including from the Universities of Cambridge and Sydney, showed that about 1.25 hours of brisk walking per week could yield an 18 percent lower risk of depression compared with not exercising.

"Most benefits are realized when moving from no activity to at least some," the study authors wrote, in the paper published in the journal JAMA Psychiatry.

"Our findings have important new implications for health practitioners making lifestyle recommendations, especially to inactive individuals who may perceive the currently recommended target (of exercise) as unrealistic," they added.

The team conducted a meta-analysis of 15 studies involving over 190,000 people to determine how much exercise was needed to reduce depression.

The findings revealed that moving up to an "activity volume equivalent to 2.5 hours of brisk walking per week was associated with a 25 percent lower risk of depression.

The findings are consistent with previous studies that found people who exercised had about 43 percent fewer days of poor mental health.

"Even just walking just three times a week seems to give people better mental health than not exercising at all," study author Adam Chekroud, an assistant adjunct professor of psychiatry at Yale University, was quoted as saying to CNN.

Exercising in 45-minute sessions three to five times a week was the most beneficial for improving mental health, the 2018 study found. However, even doing household chores reduced poor mental health days by about 10 percent, the study said.

Another study published in 2020 found that even light exercise helped protect children against developing depression. The 2020 study revealed that 60 minutes of simple movement each day at age 12 was linked to an average 10 percent reduction in depression at age 18.

The types of the movement included running, biking, and walking, as well as activities like doing chores, painting, or playing an instrument, CNN reported. (AA/IANS)