AN OXFORDSHIRE runner has won an endurance event which saw him cover four miles every hour for 81 hours straight.

John Stocker, from Bicester, pipped Matt Blackburn to win the Suffolk Backyard Ultra event.

Starting last Saturday, Stocker completed more than 337 miles within 81 hours.

The challenge, which originates in America, saw 123 participants run 4.167 miles (seven kilometres) at Knettishall Heath nature reserve every hour until they could no longer carry on.

See also: How many members of England’s Euro 2020 squad have played at the Kassam Stadium?

They had to arrive back to the start in time for the next lap, otherwise they would be eliminated.

Stocker will not have been helped by soaring temperatures, which peaked at 25 degrees in Suffolk this week.

Organisers of the event said that both Stocker, 41, and Blackburn, 35, beat the previous world records for the endurance challenge.

They said the previous record of 312 and a half miles in 75 hours was set by Belgian dentist Karel Sabbe in October.

After both Stocker and Blackburn completed their 80th lap, the latter pulled out during lap 81, with the stage set for Stocker to claim the victory.

Read more: Kieran Bird brimming with belief as Olympics draw nearer

He still had to complete the lap though as had he either pulled out or not finished the lap within an hour, no winner would have been declared.

However, Stocker completed the loop in 52 minutes – his slowest lap – to win the event.

Stocker typically took between 45 and 50 minutes to finish the laps, leaving him 10 to 15 minutes to eat and drink, have a quick nap or take a toilet break before heading out again for the next lap.

Race director Lindley Chambers told the BBC: “What these guys have achieved is pretty incredible.

“I knew we had the calibre of people taking part and I personally thought we’d do 50 or 60 loops but these guys have gone beyond my expectation.”