Scientists Determine the Exact Amount of Time We Should Be Spending Outside

The average adult spends between three to four hours a day on their phones. Americans, per household, watch almost eight hours of television a day. If you have an iPhone, it will try to tell you exactly how much time you spent on social media per day. We’re well aware of the time we spend online. What a study released Thursday in Scientific Reports asks is how much time we spend outdoors.

"Yeah, I get that nature is good — but how often do I need to go and how long do I need to stay?"

The study determines the amount of time we should be spending outside, beyond the confines of our standing desks and blue light blocking glasses. The amount of outdoor time that leads to the most benefits, they write, is 120 minutes a week.

It doesn’t matter if those two hours are spent outdoors all at once or broken up into several shorter visits throughout the week. If they achieve that total amount of time outdoors, they will reap the benefits in terms of improved health and well-being.

The team, led by first author Matthew White, Ph.D., a senior lecturer at the University of Exeter, has done a lot of work over the last decade on the benefits of being exposed to nature.

“The million dollar question was always, ‘Yeah, I get that nature is good — but how often do I need to go and how long do I need to stay?’” White tells Inverse.

Motivated by this “common sense but sensible question,” they set out to find the answer. Using data on 19,806 adults in England who participated in a nationally representative survey, they examined the links between recreational contact with nature and self-reported health and well-being. Weekly contact with nature was measured in 60-minute blocks, and the team controlled for factors like time spent in residential green space (like a front yard), which didn’t count.

Their analysis showed that people who spent between 120 to 179 minutes (the range is a result of their time metrics) in nature — places like park fields and woodlands — had a significantly greater likelihood of reporting good health or high well-being compared to the week before. Well-being, in this study, is defined the level of a person’s satisfaction with their life.

Spending fewer than 120 minutes a week in nature was not associated with these improvements. Notably, spending 200 to 300 minutes was not associated with additional benefits. These patterns appeared universal across all societal groups.

While numerous studies have demonstrated that being outdoors induces positive and mental effects, this study is unique in its focus on 120 minutes. Similar research has emphasized different amounts of time in regard to different metrics of health and well-being: A 2015 study, for example, showed that people who spent just 90 minutes a week in a natural setting were less likely to focus on negative emotions. In 2010, University of Essex researchers found that just five minutes of working out in green spaces improved an individual’s self-esteem and mood.

The next question for White’s team is figuring out why 120 minutes, specifically, is so important. He reiterates, however, that 120 minutes is not a “one size fits all” situation. Two hours a week can fit into different types of lifestyles: Busy people can head out on a hike over the weekend, while retired people can take smaller trips throughout the week. Their framework can be adapted to your own life circumstances, as long as the goal is reached by the end of a week.

While motivating individuals to take advantage of the outdoors is one of the team’s goals, White hopes that the impact of this type of research is farther-reaching.

“I’d love it to be support for funding the protection of safe, biodiverse, rich natural spaces that people can spend time in,” White says. “And above all, [for it to help] people living in more deprived areas who currently tend to have poorer local access to nature.”

Abstract:

Spending time in natural environments can benefit health and well-being, but exposure-response relationships are under-researched. We examined associations between recreational nature contact in the last seven days and self-reported health and well-being. Participants (n = 19,806) were drawn from the Monitor of Engagement with the Natural Environment Survey (2014/15–2015/16); weighted to be nationally representative. Weekly contact was categorised using 60 min blocks. Analyses controlled for residential greenspace and other neighbourhood and individual factors. Compared to no nature contact last week, the likelihood of reporting good health or high well-being became significantly greater with contact ≥120 mins (e.g. 120–179 mins: ORs [95%CIs]: Health = 1.59 [1.31–1.92]; Well-being = 1.23 [1.08–1.40]). Positive associations peaked between 200–300 mins per week with no further gain. The pattern was consistent across key groups including older adults and those with long-term health issues. It did not matter how 120 mins of contact a week was achieved (e.g. one long vs. several shorter visits/week). Prospective longitudinal and intervention studies are a critical next step in developing possible weekly nature exposure guidelines comparable to those for physical activity.