100 RAF personnel are this week trying to beat the world record for 100 people each running 10 kilometres, one after the other in a relay format.
Senior Aircraftman Michael Kallenberg, one of the Air Force's top long-distance runners, organised the endurance running record attempt as part of its centenary celebrations.
It's taking place at RAF Cosford over the next three and a half days, with the aim of beating the previous record of 69 hours, 6 minutes and 52 seconds, which was set in the US three years ago.
SAC Kallenberg admitted to Forces Network that "it's going to be a challenge" but added:
"It's a lot of running, a lot of work for the athletes, a lot of work for the timekeepers and the spectators - but we've got the calibre of athlete to do it, so it's going to be interesting."
He and his fellow athletes will have to average around 41 minutes per 10,000m to beat the record, covering a total distance of 1,000,000m.
The attempt was kicked off by the chairman of the RAF Athletics Association, Group Captain John Lawlor, who had suggested to SAC Kallenberg and other top RAF runner Ben Livesey that the Air Force try to break a record in its centenary year.
The RAF last entered the athletics record books in 1984, when Steve Jones broke the marathon world record, before his time was surpassed the following year.
SAC Kallenberg has had to select his runners carefully ahead of the attempt, taking a number of factors into consideration. He said:
"The challenge [has been] trying to find the 100 athletes that can maybe run a bit quicker because [although] most of the guys can run 39 minutes [or] 40 minutes, you've then got to take into account they're running on their own, some are at night, it could be cold, it could be wet, you're going to be tired. It's going to be tough."
For their Guinness World Record to be ratified it, the RAF team will have to record every single second of every run.
SAC Kallenberg will run the last leg - but is hoping a lot of the hard work will have been done by then:
"I'm hoping the guys will give me a nice buffer, so it'll be a case of 'You've got an hour to spare, enjoy the last 10k!' and not a case of 'Right, knock out a PB [personal best] quick!'"
The team are hoping to be finished at around 10am UK time on Thursday morning - keep your eyes on Forces Network for updates on how they get on.
Cover image courtesy of 10kRAF100 via Twitter.