Taking a walk in the fresh air has mental as well as physical benefits - as it can help the brain.
During the Covid-19 pandemic many people took to walking outdoors as a rare permitted activity during lockdown, and a new study from researchers at the Max Planck Institute for Human Development and the Medical Center Hamburg-Eppendorf (UKE) suggests we should all keep up the habit.
Their neuroscientific study found that even relatively short walks have a good effect not only on our general well-being but also on our brain structure. Until now, it was assumed that our environment only impacts us over longer periods of time.
Scientists regularly examined six healthy, middle-aged city dwellers for six months, scanning their brains using magnetic resonance imaging (MRI) and self-reported behaviour as to whether they had been outdoors prior to imaging.
They were also asked about their fluid intake, consumption of caffeinated beverages, and physical activity, in order to control for these factors, and the duration of sunshine in the study period was also taken into account.
"Our results show that our brain structure and mood improve when we spend time outdoors. This most likely also affects concentration, working memory, and the psyche as a whole," says Simone Kühn, the lead author of the study.
Brain scans show that the time spent outdoors by the participants was positively related to grey matter in the right dorsolateral-prefrontal cortex, which is the superior (dorsal) and lateral part of the frontal lobe in the cerebral cortex.
This part of the brain is involved in the planning and regulation of actions as well as cognitive control - with many psychiatric disorders being associated with a reduction in grey matter in this area.
The researchers' calculations revealed that time spent outdoors had a positive effect on the brain regardless of the other influencing factors.
Co-author Anna Mascherek adds: "These findings provide neuroscientific support for the treatment of mental disorders. Doctors could prescribe a walk in the fresh air as part of the therapy - similar to what is customary for health cures."
In future studies, the researchers also want to directly compare the effects of green environments to urban spaces on the brain to see if the quality of outdoor experiences has an influence.