The Swedish phenomenon of "plogging", where joggers combine their run with picking up the trash they find in nature, is going global as both environment and fitness fanatics benefit from the new trend.
Started in 2016 by Swede Erik Ahlstrom in the town of Are, which hosted the recent Alpine skiing world championships, the craze is now spreading around the world.
"The world record is actually in Mexico City, four thousand people have been plogging in one day, but I think it's about 10 thousand people doing it regularly in India. In India, the biggest trend for running, it's plogging right now," Ahlstrom told Reuters at a recent plogging event in Stockholm.
"In Swedish 'plocka' is pick, and then jog of course. It's a combination word, it's two words put together - pick and jog," Ahlstrom explained as he handed out trash bags to over two dozen trail runners who were joining him for the evening.
Ahlstrom sent the ploggers on their way with a stirring pep talk about the three million cigarette butts that are thrown away in Sweden every day and the amount of plastic in the world's oceans.
"Most of that plastic comes originally from the land, so when we run, let us run with purpose!" he enthused before ringing a bell to send them on their way.
The ploggers quickly left the pathway and disappeared into the bushes and trees to spend their evening collecting plastic and paper that they would later dispose of in a trash can near their starting point.
Ahlstrom said he is delighted by the interest now being shown around the world, but he's not surprised.
"It's so easy, and plogging burns more calories than normal running - you have to bend and squat, it's good for the legs and you get a better body," he explains.
The Swedes are well-known for their love of nature and their environmental conscience, with teenage climate activist Greta Thunberg gaining world-wide fame after her school strike outside government buildings in Stockholm created a global movement.
Trail runner Lena Lagerljung, who has been taking part in events with Ahlstrom since he started in 2016, says that plogging has become her contribution to that debate.
"I can't sit like Greta outside the parliament, I have to do this," she said with a laugh.