Scientists are increasingly uncovering how just 20 minutes in a park or woodland can deliver striking health benefits, matching the effects of more elaborate wellness routines. A major 2019 UK study of nearly 20,000 people found that those spending at least two hours a week in natural settings reported far better health and psychological wellbeing.
Japanese research on forest bathing points to similar gains kicking in after only 20 minutes, activating the body’s rest and digest response.
When surrounded by trees, fresh scents, and birdsong, the autonomic nervous system shifts gears, slowing heart rates, easing blood pressure, and promoting calm.
“We see changes in the body such as a lowering of blood pressure, a change in your heart rate variability and your heart beats slower—all associated with physiological calming,” said Baroness Kathy Willis, a biodiversity professor at Oxford University, on BBC Radio 4’s What’s Up Docs?.
Nature also resets stress hormones like cortisol and adrenaline while boosting immune cells. One experiment exposed participants to Hinoki cypress oil over three days, triggering a sharp drop in adrenaline and a surge in virus-fighting natural killer cells that persisted for weeks.
“A study found that people in a hotel room for three days who were breathing in Hinoki (Japanese cypress) oil saw a big drop in the adrenaline hormone and a large increase in natural killer cells in their blood,” Willis noted.
Prof Ming Kuo of the University of Illinois explained that nature “calms what needs calming and strengthens what needs strengthening.” She added, “A three-day weekend in nature has a huge impact on our virus fighting apparatus and even a month later it can be 24% above baseline.”
Plant aromas and soil microbes further enhance these effects, enriching the gut microbiome much like probiotics. “They’re the same kinds of good bacteria we pay for in probiotics or drinks,” Willis said. Phytoncides from trees fight inflammation, and experts like infection specialist Dr Chris van Tulleken describe nature as a space that “tickles your immune system.”
For those short on access, indoor alternatives suffice: a vase of white roses, a pinene diffuser, or even a nature photo on your screen can reduce stress. “Every bit seems to help,” Kuo affirmed. Initiatives such as the NHS’s green social prescribing are putting this science into practice, linking people to green spaces with promising results on happiness and health.