A walk in the woods can leave you calmer, sharper and in a better mood, and researchers have started to measure why. Brain scans, creativity tests and attention tasks have all been used to compare time in nature with time in the city. Here are four well-known studies behind the claim that hiking changes your brain, and what each one found.

Hiker graphic with the quotation “The best view comes after the hardest climb”

The Stanford walk: less rumination after 90 minutes in nature

In 2015 Gregory Bratman, James Gross, Gretchen Daily and colleagues at Stanford University published a study in the Proceedings of the National Academy of Sciences. They sent 38 healthy adults on a 90-minute, 5.3-kilometre walk: half through greenspace near the Stanford campus, half along El Camino Real, a busy multi-lane road in Palo Alto.

Afterwards, the nature walkers reported less rumination – the habit of dwelling repeatedly on negative thoughts – while the city walkers showed no change. MRI scans also showed reduced blood flow in the subgenual prefrontal cortex, a brain area linked to rumination, in the nature group only. Heart rate rose equally in both groups, so the difference was not down to physical effort.

Creativity in the wild: four days without screens

A 2012 study in PLOS ONE by Ruth Ann Atchley, David Strayer and Paul Atchley worked with 56 adults on Outward Bound backpacking expeditions in Alaska, Colorado, Maine and Washington, with no phones or electronics allowed. Participants took the Remote Associates Test, a creative-reasoning puzzle, either before setting out or on the fourth day of the trip.

The group tested in the wilderness averaged 6.08 correct answers out of 10, against 4.14 for the group tested before leaving: a 50% improvement. The authors note that the design cannot separate the effect of nature from the effect of switching off technology, since both happened together.

Walkers following a path through a green forest – photograph by Mike Heller
Photo: Mike Heller.

Park walks and children with ADHD

Andrea Faber Taylor and Frances Kuo studied 17 children aged 7 to 12 with diagnosed ADHD, published in the Journal of Attention Disorders in 2009. Each child took a guided 20-minute walk in three settings – an urban park, a downtown area and a residential neighbourhood – on different weeks.

The children concentrated better after the park walk than after either of the others, with scores approaching those of children without ADHD. The researchers compared the size of the effect with that of two common ADHD medications, and the children themselves rated the park walks more positively.

Aerobic exercise and the hippocampus

A six-month trial led by Lisanne ten Brinke and published in the British Journal of Sports Medicine followed 86 women aged 70 to 80 with probable mild cognitive impairment. They trained twice a week in aerobic exercise, resistance training or a balance-and-tone control programme. Aerobic training significantly increased the volume of the hippocampus, the brain region central to memory. The authors called for more research on whether that growth translates into better memory.

Planning a walk that works for you

None of these studies needed a mountain summit. The Stanford walk passed through greenspace near campus, and the ADHD study used an ordinary town park. Choose a route by its distance, elevation and surface, carry water and suitable footwear, and keep your phone for navigation while silencing the rest. Check official route notices before you go: our Azores guide links to the islands’ trail directory, and our Riomaggiore guide covers the Cinque Terre paths.

For ideas, try the gorge path in our Vintgar Gorge guide, the routes in the four scenic walks guide, or a walk by the sea, explored in our piece on blue spaces and wellbeing. Heading out alone? Our independent trip planning guide explains how to keep offline maps and key information to hand.

Sources