ON the eve of the biggest challenge of his career Nathan Montague will be spending time in the kitchen of his self-catering apartment in the French Alps.

While the Swindon Harrier might prefer to put his feet up to save his legs ahead of the legendary Ultra Trail Mount-Blanc running event Montague knows that cooking up his customised supplement will be essential to ensuring he reaches the finish line.

That’s because the UTMB is no ordinary race. This is a gruelling physical and mental assault measuring 170 kilometres and incorporating 10,000 metres of ascent through the Alps that starts at 6pm tomorrow and goes through the night before the leading survivors cross the finish line around 20 hours later.

“I am very meticulous in what I eat and I don’t rely on what is provided by the organisers at the checkpoints on the course because I am a coeliac and need gluten and wheat free food,” said Montague.

“So on Thursday night I will be making small portions of cheesy mash with plenty of salt and milk because that will give me protein and carbohydrates and isn’t too sweet.

“You don’t have to chew it and I find it goes down pretty well while running. I make small balls of this and bag them up and will eat one every hour and alternate with a gluten and wheat free energy bar, bananas and electrolyte drinks.”

Rehydration and maintaining energy levels are essential on a race of this duration and intensity, as are the requirements of personal safety in the mountains when weather conditions can change quickly.

“Over 20 hours the temperature can vary from 27C to below zero so the organisers demand that you take certain equipment with you,” added Montague.

“You must have a waterproof and breathable jacket and trousers, both of which can be folded up to knuckle size, waterproof gloves, a spare base layer, a bandana-scarf, two head torches in case one fails, a foil blanket and a bandage.

“I also carry my mashed potato balls, energy bars and one-and-a-half litres of fluid which can be topped up along the way.”

Only then will Montague be armed and ready to join over 2,000 other runners from across the world for his first UTMB which is revered as iconic by the ultra running community.

“I would say I am excited but also nervous and apprehensive,” said Montague.

“It is the sort of event that could go fantastically well – or horribly wrong! If you think about the distance and the climbing too much it could petrify you.

“But in my mind the first goal is to get to the end in one piece, that will be a fantastic achievement.”

If Montague does that then surely he can treat himself to a real slap-up meal.