Three Surrey adventurers will be pushing themselves to the limit in the wilderness of Chilean Patagonia this month in a bid to secure the ultimate prize in the extreme sport of adventure racing – and in doing so they aim to help raise awareness of the region’s fragile environment.

The trio will be part of a field of 15 international four-person teams in the Wenger Patagonian Expedition Race, an endurance event that begins on February 8 and will see competitors battle on bikes, kayaks and foot through some of the world’s most wild and remote virgin territory.

Andy Wilson, 41, from Surbiton, and Mark Humpfrey, 36, from Bagshot, will be returning as reigning champions with Helly Hansen-Prunesco having beaten off competition from nine other teams in last year’s event, while Mark Childs, 39, from Guildford, will take on the race for the first time with his team Fast & Light.

Humpfrey, who works for VolkerFitzpatrick and has raced for seven years, said: “I’ve been to some amazing places doing this, and when you explain what you have just done, people just think ‘oh, that’s nice’. We put a huge amount of effort in just to get there and we go through a lot when we are racing. I am looking forward to going back and I hope we can win it again!”

The competition, which has grown a reputation as the toughest event of its kind, will take place over more than 600km and will push competitors to the very limit of exhaustion both mentally and physically, with many likely to suffer wild hallucinations due to sleep depravation.

“I could have sworn I saw a car headlamp up the hill in the middle of a forest at one point,” recalled Humpfrey.

“I lost the plot a bit, shouted loads at everyone, and went up to go and have a look. It took me ten minutes to realise it was just the moon through the trees.”