London - City dwellers should visit parks more often and take advantage of this free and easy way to boost their physical and mental health, environmental scientists have urged.
It found that bigger parks with more trees and vegetation – as well as plenty of flowers – had a more significant mood-boosting effect than smaller ones.
And the elevated mood that a visit to a park brings lasts "like a glow" for up to four hours afterwards, the researchers said.
The US study was based on an analysis of hundreds of tweets posted every day by people visiting 160 parks in San Francisco.
They used happier words and expressed less negativity on Twitter than before their visit, according to the scientists from the University of Vermont.