Four local sportsmen are beginning one of the greatest challenges of their lives today (Friday).

Nicky Rees, Matthew Evans, Steve Rogers and Dafydd Lewis are off to compete in the Marathon des Sables, otherwise known as the toughest footrace on earth.

Known simply as the MdS, its is a gruelling multi-stage adventure through a formidable landscape in one of the world's most inhospitable climates - the Sahara desert.

It's a multi-day 'ultra-marathon' or 'ultra' run in six days over a course of between 150 and 156 miles.

The rules require entrants to be self-sufficient, to carry with them on their back everything except water that they need to survive. They are given a place in a tent to sleep at night, but all other equipment and food must be carried.

Places are much sought-after in the race. Around 1,300 runners from around the world will be taking part. Under the scorching Moroccan sun, they will share experiences of unforgettable days spent running across saltpans, up desert-mountains, through ruined towns and through the occasional sand storm.

"I think we are all very excited, but apprehensive at the same time," said 47-year-old Pembrokeshire College lecturer and Tenby fireman Nicky.

"It will be an incredible experience," added Steve, who runs his own building company in Narberth, and will be celebrating his 43rd birthday during the event.

"It's something we may never do again or may even get the bug and want to repeat the experience."

Whilst Matthew, CEO of Activity Wales, quipped: "Plane food on the return journey will never have tasted so good!"

The quartet are each being motivated by the charity they are raising money for - Nicky for friend Gareth Scotcher and the Motor Neurone Disease Society, Matthew for Medullary Thyroid Cancer from which his mum suffers, Steve for Mencap for his brother-in-law who has Down's Syndrome and 34-year-old Whitland businessman Dafydd for Prostate Cancer UK, the chosen charity of Whitland Rugby Club where he was a former player.

The race starts on Sunday with tracking on progress of the runners - Nicky (number 141), Matthew (103), Steve (479) and Dafydd (368) - via the website http://www.marathondessables.com">www.marathondessables.com You can also log into the write to the competitors section and send them a message which will be given to them each evening.