Yes, another piece of evidence that simply getting outside into nature is just what the doctor should be ordering: BBC News reports that a study in the journal Environmental Science and Technology shows that as little as five minutes of exercise in a "green space" can give you a mental health boost. Add a body of water into the mix and the effect is even greater.

The researchers examined evidence from ten different studies and found that the biggest boost occurred within those first five minutes, and though it declined from there on out, the positive effect was still apparent with longer time spent outside. Particularly strong effects were found with children and the mentally ill.

Study leader Jules Pretty:

A challenge for policy makers is that policy recommendations of physical activity are easily stated but rarely adopted widely. Employers, for example, could encourage staff in stressful workplaces to take a short walk at lunchtime in the nearest park to improve mental health.

My suggestion: Don't wait for some health official to tell you how much exercise and time outside you need, or a study to tell you the benefits. Just pay attention to how you feel when comparing the change in mood from spending time in your life-killing office to how you feel in the park and prioritize the one that feels better.

Read more: 'Green' exercise quickly 'boosts mental health'

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