This is Scientific American ― 60-Second Science. I'm Jason Goldman.By now it's almost common knowledge that spending time in nature is good for you.Areas with more trees tend to be less polluted, so spending time there allows you to breathe easier.Spending time outdoors has been linked with reduced blood pressure and stress, and seems to motivate people to exercise more."So it'll come as no surprise that there's research showing that spending time in nature is good.I mean, that's been known for millennia. There's dozens of papers showing that."University of Exeter Medical School researcher Mathew P. White."We get this idea, patients are coming to us and they're saying, 'doctor, how long should I spend?'and the doctor is saying, 'I don't really know.'"So White and his team decided to find out by using data collected from nearly 20,000 people in England through the Monitor of Engagement with the Natural Environment Survey.And their answer? Two hours a week.People who spent at least that much time amid nature―either all at once or totaled over several shorter visits―were more likely to report good health and psychological well-being than those with no nature exposure.Remarkably, the researchers found that less than two hours offered no significant benefits.So what's so special about two hours?"I have absolutely no idea. Really. We didn't have an a priori guess at what this would be, this threshold.It emerged. And I'd be lying if I said we predicted this. I don't know."
