Engaging in physical activity in a natural setting is good for your mental health, even for as little as five minutes per day, say researchers of a new study published in the American Chemical Society’s semi-monthly journal Environmental Science & Technology.

A number of researchers have documented the beneficial mood effects of spending time engaging in physical activity in natural settings, but until now, no one had focused on how much time a person needed to spend outdoors in order to get a mood-boost.

After analyzing a number of studies, including over 1,200 people, Jules Pretty and Jo Barton found the answer: about five minutes. That’s it.

Whether gardening, hiking, running or biking, simply being active in the midst of greenery helped boost mood, particularly in young people and in people suffering from a mental illness. In fact, throw in a little water--a mix of green and blue--and the effect was even greater.

So next time you’re down, and your tree-hugging friend suggests taking a walk in the park, take them up on it. And next time your local area votes on measures to preserve or expand on green spaces, vote green. Your mind and heart may thank you later.