An British sportsman who ran 80 miles along a French motorway after competing in a mountain endurance race has been cautioned by local police.

The man, aged 29, who has not been named, set off to run more than 100 miles from the Valmorel ski resort to Lyon airport after taking part last weekend in the Spartan Race, a gruelling obstacle course in the snow.

“Apparently his legs were still good after the race and he decided to run all the way to the airport,” a police source said.

He was listening to music on headphones and did not hear police warnings over loudspeakers when he was eventually intercepted on Monday.

The source said: “He was running along the hard shoulder, wearing a hat and blasting his music, so he couldn’t hear us summoning him over loudspeakers. We told him it was illegal to run there but he didn’t seem to understand why. We picked him up and he told us he was determined to run to the airport. We told him, ‘you can’t run on the motorway, it’s not a running track.’”

After breathalysing him, the gendarmes dropped him on a secondary route and gave him directions to run the remaining 24 miles. They let him off the €4 (£3.50) fine for walking on the motorway, which the officer pointed out is “derisory compared to the danger”.