Eighth-placed Challenger finisher Warwick Gooch, right, leads The Spine runner Joel Jaile Casademont on the descent of Pen-y-ghent last year

Almost 100 hardy runners are gearing up for what has been described as Britain’s most brutal race.

The Spine starts this Saturday and involves a non-stop course following the whole length of the country’s first national trail, the Pennine Way.

Competitors have to cope not only with the physical challenge of running 268 miles (431km) along the spine of England, and whatever the winter weather throws at them, but also prolonged periods of night navigation due to the short daylight hours.

There’s also the matter of 11,759m (38,579ft) of ascent and a time limit of 168 hours to arrive at the finish point at Kirk Yetholm in the Scottish Borders.

For those not quite up to the full course, the concurrent Challenger race involves a 108-mile (174km) trek along the southern part of the Pennine Way.

Racers will pay £550 for the masochistic privilege of taking part in The Spine, which is sponsored by outdoors brand Montane. Other supporters are PrimaLoft, Petzl and PNY.

Mark Caldwell, who has finished The Spine twice and the Challenger once, said: “The Spine Race is easy apart from: it’s dark most of the time; your feet then body will fall apart; the compulsory baggage doesn’t get any lighter; sleep is a luxury; you experience extremes of weather and cold; and finally of course it’s 268 miles long.

“Many will try to break The Spine but most will become race statistics. Good luck to all who enter.”

Last year’s race was run in relatively mild conditions and was won in a record time of 4 days, 14hrs, 45mins by Czech runner Pavel Paloncy, closely followed by Matt Davis and Steve Holyoak. Paloncy is on the entrants list to defend his title.

Debbie Brupbacher smashed the ladies record coming home in 6 days, 9hrs 17mins, chased all the way by 2013 Challenger winner Anne Green who came in a few hours behind.

Competitors in The Spine. Photo: Border Search and Rescue Unit

The Spine race was first attempted in January 2012, with only three athletes completing the course. Joint winners Gary Morrison and Steve Thompson were closely followed by Mark Caldwell.

The following year The Spine was hit by Arctic conditions with some runners needing rescue from the North Pennine and Cheviot hills.

Eugeni Roselló Sole won the 2013 event in 5 days 4hrs 52mins with Annabel Gates completing the race as first female in 7 days 4hrs 59mins.

The 2015 Montane Spine race will start at 9.30am this Saturday, 10 January, from Edale, with Challenger competitors setting off three hours earlier.

More details are on The Montane Spine website.