In pictures: The UAE man running around the planet

Handout picture of the Atacama Crossing. Courtesy www.racingtheplanet.com

Handout picture of the Atacama Crossing. Courtesy www.racingtheplanet.com

For 1,000km of pain and deprivation in some of the planet's most inhospitable environments, the payback will be having raised enough money for the UAE-based Operation Smile charity to fund 100 facial reconstructions for underprivileged children born with ???

"I was looking for a charity in the UAE. I'm getting paid here and all my money is tax free here so I thought I might as well support something based here," he says. Operation Smile met his checklist of a local, transparent and useful organisation, so he ???

Handout picture of the Gobi March. Courtesy www.racingtheplanet.com

His next race will be the Gobi March in western China. The terrain - sand dunes, rocky trails, steep hills, ridges and riverbeds - is inhospitable but it is the strong winds in the area that are notorious for tormenting runners.

The Antarctic leg is the fourth and final leg in his series in the summer of 2015. "They all have their own challenges. Antarctica will be the coldest," Pontifex says.

Handout picture of the Last Desert. Courtesy www.racingtheplanet.com

He is already looking beyond the four desert races, thinking about a mammoth endurance event closer to home to raise money and awareness for Operation Smile. "I'm looking for a big event in the UAE," he adds. "Maybe running from the Saudi border to Ras Al???

The Sahara Race in Egypt is the hottest of the four races and mostly based on loose sand.

"You've got to take everything for five days with you. They provide tents for eight to 10 people to sleep in and they'll supply you with water every 10km," he says. You have to have your sleeping bag, medical kit, clothes. We've managed to whittle it down???

"A 10kg pack slows you down by about half an hour over 10km. You look at some of the times to do 42km and some people are taking nine hours.