A great friend of mine, a mad dutch woman did it in her forties. Her training was done mainly in West Africa. In fact she did one marathon session around the Freetown peninsular with both |Malaria and Typhoid!!!!
She did it with a young TA Captain ( female) of about 26. If they can I am sure you can.
Being a fan of the marathon des sables I was going to post this link but you beat me to it Bossdog. Love this quote from it:
"Its tempting to underestimate the power of blisters, and without the pictures I cant really show you the extent of some peoples trouble, so Ill take one guy as an example. He lost all the skin off the base of his heels on the first day. They only got worse: by the end he had no epidermis on his feet at all, and the doctors were checking him at every checkpoint. He was walking on raw meat and exposed nerve endings for most of the race. He finished. English."
A couple of friends did it in 2005, I few out to Morocco meet them at the finish line. Here's a rather good diary of the event from one competitor Charlie Norton
As taken from the article, it seems the British have an affinity for understating hardship:
Age breeds stamina and mental toughness but for pure stoicism it was hard to match the British contingent of over 200. Most would pride themselves on not complaining about the hardship of the race and having a laugh over everything.
I saw one Brit crawling up a dune looking as though he was at death's door, but when he was asked how he was he said: "Just a moment of bother."
Read the account by Dr Mike Stroud an MoD doctor and complete loon who did it a few years ago. His book is called Survival of the Fittest. And is an excellent book about human fitness and endurance.....