“I do to my body what we do to the planet,” Nicolas Vandenelsken, who calls himself an “eco-adventurer,” told AFP as he reached Paris on his 84th marathon, having crossed 10 regions since September 3.
His itinerary of 42.2-kilometre (26.2-mile) marathons is to resemble a heart when seen on a map of France.
Vandenelsken — an activist in two associations dedicated to climate awareness in sport — has met children, associations and farmers along the way.
In Paris, he had a meeting with French Sports Minister Amelie Oudea-Castera, saying he told her, “Sport is an incredible lever to reach a maximum number of people.”
Vandenelsken, who had doctors check his fitness before setting out, told AFP that “with my mental strength and with my training, I am able to get through this.”
But he added: “I wouldn’t advise anybody to run 100 marathons in 100 days, because I expect to feel the impact of this in my joints in five or 10 years’ time.”
Vandenelsken timed his runs to coincide with the football World Cup in Qatar which has been criticised for, among other things, its carbon footprint.
But he told AFP his concern went well beyond one major event.
“All these big organisations should think first of respecting the integrity of nature before thinking about the business of sport, before thinking about money,” he said.
Among concrete measures, Vandenelsken said he would like to see transport quotas for major events like cycling race Tour de France, and renovation of existing sports infrastructure rather than building them from scratch.
“My aim is to get a law voted,” he told AFP.
His final marathon is to take him to Valenciennes, in northern France, on December 10.