We know spending time outside is good for us: Nature reduces anxiety, promotes creativity and promotes good heart health. Time outside can even help us problem solve and gain perspective about what’s bothering us. But until recently, researchers have struggled to figure out what “time outside” really means. Is it 30 minutes per day? Five hours per week? And do city green spaces count, or do people only get nature’s benefits when they head to the mountains?
A recent study published in Nature answered several of these questions in a new way. It found that there is, indeed, an ideal amount of time when the benefits of being outdoors start accruing: 120 minutes per week. That’s two hours each week, and the benefits appeared to max out at between 200 and 300 minutes on a weekly basis.
Researchers found it didn’t matter how people spent the 120 minutes—the quota could be met in one long visit to nature or during several shorter ones. Both city green spaces and green spaces in less urban areas had a positive impact, too.
The research is an interesting starting point for eventually prescribing time in the outdoors. If care providers hope to offer outdoor time as an intervention for their patients, study author and researcher Dr. Ian Alcock said, they need to know how long people should spend in nature.
“[This] work [will help us start] discussions about providing simple, evidence-based recommendations about the amount of time spent in natural settings that could result in meaningful promotion of health and well-being,” he said.
Alcock and his co-authors looked at data from the National Environment Survey, which included information collected from 4,000 adults living in England between 2014 and 2016. The scientists analyzed the data in one-hour blocks, comparing how people felt (did they report good health and high well-being?) after being outside after each additional hour in the outdoors.
Participants were much more likely to report good health and high well-being once they surpassed the 120 minute mark. (In fact, people who spent between one and 119 minutes outside per week reported the same amount of well-being as people who spent no time outdoors at all.) Benefits seemed to peak at between three to five hours, with no additional gain from more hours outside. This was true for people of all ages, including older adults and people with long-term health issues.
Perhaps the most interesting finding was the fact that people could get the 120 minutes however they liked. Some participants took daily 20-minute walks. Others spent the better part of a Saturday hiking in the mountains. Still others went to the park for a short picnic. Across the board, all of these participants reported improved well-being overall.
Alcock says we can’t speculate too much more about the results, though. Researchers still need to look at what this “well-being” factor means. In the future, they hope to use data collection that doesn’t rely on self-report methods, as people’s own assessments of their feelings and behaviors are often less reliable than objective measures. In the future, Alcock also plans to investigate how people’s ideas about their environment and the people around them change after time in nature.
And there are other lingering questions: Would these same results show up if the study were conducted in the United States? Does the safety of green spaces matter? And do our feelings about spending time outdoors—our nervousness or excitement—impact the benefit we get from those 120 to 300 minutes? All of these questions will be subject to future research. In the meantime, we can take this first study as a powerful reason to get outside each week, even if it’s just for an evening walk.