As Dame Sarah Storey makes her attempt on the Hour Record today, Australian cyclist Jack Bobridge has given an insight into the extraordinary physical challenge, describing it as ‘the closest you can come to death without dying'.

Bobridge missed out on breaking the men’s Hour record in January, falling three laps short of the record which was at that point held by Austria’s Matthias Brändle, but which has since been broken by Bobridge’s countryman, Rohan Dennis.

Speaking to the Telegraph, he explained the nature of the challenge bluntly and simply, saying: “Having a shot at the hour world record is the hardest thing you can possibly do as a cyclist.”

He describes starting with ‘a real buzz’ thanks to the crowd and the music. “You’ve got your aero helmet on, and you can feel the wind in your face.” However, after a while, the pain started to kick in.

“After those first 20 minutes I was thinking: 'this is going to be a seriously long hour'. My glutes, quads and groin were starting to hurt like hell and the pain was so intense. I have been in agony on the track before, but the fatigue from the hour was something different.

“You have no control over it. You just have to keep going, no matter how hard it gets. And you have to put up with serious g-force from all the bends which is a real strain on your shoulders and your arms.”

Around halfway through, Bobridge started falling behind on his lap times. He says that he knew he could get back to where he needed to be, but the pain was getting worse and worse and in the end he was just trying to salvage things and do the best that he could do.

“With 15 minutes to go my body was screaming at me to stop, but I couldn’t. I remember accidentally hitting a few foam sponges (which line the inside of the track) and I was praying to God I got a puncture so I could stop, but it didn’t happen. If I had punctured, I would have been gutted, but those are the dark thoughts that go through your head.

“I have never felt like I did at the end of that hour. You have been in pain for an hour and you have not taken on any fluids so that level of fatigue and dehydration was something new. I was in that much pain I couldn’t walk. My glutes and my groin were so cramped and damaged. I think it was the closest I could feel to death without actually dying.”

Dame Sarah Storey is attempting to break the women’s UCI Hour Record in London today as part of the Revolution series.  She is the first woman to attempt the record since the UCI changed its rules last year to accommodate modern track bikes and equipment and is looking to beat the 46.065km set 12 years ago by Leontien Zijlaard-van Moorsel of the Netherlands.