Taking a breath of fresh air could significantly lower depression and improve mental health, according to a recent study.

Researchers from the University of Michigan found that group nature walks are linked with significantly lower depression, less perceived stress and enhanced mental health and well-being. People who had recently experienced stressful life events like a serious illness, death of a loved one, marital separation or unemployment especially saw a mood boost after outdoor group walks.

"Walking is an inexpensive, low risk and accessible form of exercise and it turns out that combined with nature and group settings, it may be a very powerful, under-utilized stress buster," Sara Warber, senior author of the study, said in a statement. "Our findings suggest that something as simple as joining an outdoor walking group may not only improve someone's daily positive emotions but may also contribute a non-pharmacological approach to serious conditions like depression."

For the study, researchers evaluated nearly 2,000 participants from the Walking for Health program in England, which helps facilitate nearly 3,000 weekly walks and draws more than 70,000 regular walkers a year.

"We hear people say they feel better after a walk or going outside but there haven't been many studies of this large size to support the conclusion that these behaviors actually improve your mental health and well-being," Warber said.

Given the increase in mental ill health and physical inactivity in the developed world, researchers are constantly exploring new, accessible ways to help people improve their long term quality of life and well-being.

Based on the findings, group walks in local natural environments may make a potentially important contribution to public health and "be beneficial in helping people cope with stress and experience improved emotions," Warber added.

The findings were published in a special issue of Ecopsychology.