Sir Ranulph Fiennes' Marathon des Sables effort after Wales prep

Sir Ranulph will run 156 miles in six days in temperatures 50C

Explorer Sir Ranulph Fiennes has embarked on his mission to become the oldest Briton to complete the "toughest footrace on Earth" - with help from his Cardiff coach.

The 71 year old set off on the six-day Marathon des Sables (MdS) in Morocco, on Sunday.

He has been put through his paces at Merthyr Mawr sand dunes in Bridgend by ultra-marathon veteran Rory Coleman.

Coleman has completed the MdS 11 times - and more than 800 marathons.

Sir Ranulph, who has had two heart attacks and a double heart bypass, will run 156 miles (250km) in 50C (122F) temperatures in the Sahara.

He hopes to raise £2.5m for Marie Curie Cancer Care.

Ahead of the race, Coleman said: "It's going to be a tough undertaking for Sir Ranulph, he's taking on the extremes of the heat, desert storms and endless sand dunes, instead of the -50C, high altitudes, snow and ice that he's far more used to conquering.

"It's my job to get him to the finish line safely and in one piece."

Coleman trained Sir Ranulph in the dunes of Merthyr Mawr in Bridgend

The explorer has had two heart attacks and a double heart bypass

The six-day ultra-marathon is held in the Sahara