In five weeks' time, at the beginning of April, there will take place in the Sahara this absolutely insane mid-life Rite of Passage when over 800 men and women will beast themselves to breaking point.
And the true beauty of the Marathon des Sables is that no first-timer can ever truly know what they're in for. Before you start, you sort of know that it's going to be hot in the desert - and that it's probably going to be painful. And blisters: you're probably going to see a fair few of them.
But until you get out to the Sahara, and until you've experience the sand and this broiling furnace heat, you have no real concept of what the Marathon of the Sands will do to you.
Although most of this year's runners will have put in many, many hours of training, and will doubtless have read a number of books about the race, the MdS is so very different from most other endurance races, that there is no telling what it will really be like.
It's a bit like parenthood. You can read all the books. Talk to all your friends. But nothing - nothing on this earth - can prepare you for that dazzling moment when, for the first time, you hold your own baby. Or the bone-numbing tiredness that you can feel as the yowling kid rousts out of bed at 3am for the tenth straight night in a row.
So... not that you can ever really truly prepare yourself for the MdS, but here are the ten secret ways to help set you up for this eye-watering challenge. (I do assume, by the way, that you've already put in quite a few days of running with a ten-kilo rucksack. If you haven't, then getting ready for the MdS in just five weeks will be quite a stretch. You could easily - easily! - do yourself some permanent injury. Could even kill yourself. Just a thought.)
1. Mental toughness
The MdS may be an endurance race, a 150-mile slog carrying all your own kit - but it is very largely a test of mental toughness.
This is not an easy thing to acquire.
Putting in all the hard-yards training will certainly help. If you have done a couple of ultra-runs before the MdS, then you'll know that you are capable of handling pain and long distances.
When it comes to the fourth day, with the double marathon through the night, you'll have a lot of experience to fall back on.
But it doesn't necessarily mean you're battle-hardened.
You won't know about that until you're out there.
One thing that helps is an Ipod packed with your most uplifting anthems.
This music can be very powerful. Can drive you up a sand-dune when you're on the very verge of throwing in the towel.
Your Ipod is like a magic bullet. You have to save it for when the going gets really, really tough. The first time you hear those tracks, you can easily be moved to tears. It can spur you on like nothing else.
Second time you plug in your little aural comfort-blanket... Not so powerful.
Third time... it's just the same old, same old.
So take your Ipod and all your favourite tracks.
But be judicious about how you use it. Don't waste it all on the first or second days, which are merely a little taster of the treat that is in store for you.
2. Get ready for the heat
It takes about four or five days to really acclimatize yourself to the 54 degree heat of the Sahara. Generally, though, you'll just get a couple of days out in the desert before the start of the race. That is not nearly enough to prepare you the extreme heat.
Runners try and ready themselves for the heat in all manner of ways. The keener athletes book themselves off for a week in the Canaries, as they toil up and down the Tarmac roads.
Other techniques include exercising in specially heated gyms. In my own gym in Edinburgh, I've even seen people take to running machines with rucksacks and five layers of clothing. After about five minutes, their faces have turned into stewed red tomatoes.
I'm not if any of this really prepares you ready for the heat, though it does psyche you up - makes you think you've done everything you can before the race.
Best way, though, to prepare yourself for the heat - by far - is just to have a long hot bath. Run the bath as hot as you can take it, glass of red wine, a decent book... now that is my kind of training! (Not so good, obviously, if you're a guy looking to have children any time soon.)
A lot of people have this notion that all MdS training has to be hard, painful and gruelling. That is tosh! Long hot baths are as good a way as any of getting you ready for the heat and you should savour them!
3. Love your feet
One of the unfathomable imponderables about the MdS is what the hell is going to happen to your feet. Are they going to swell up by two sizes, so that your shoes are bulging at the laces? Or is your skin going to be so super-soft that you're getting blisters after the first ten miles?
Should you be getting a different type of shoe to run in the desert? Should you be dipping your feet into meths to toughen up your soles? And what's the best way to keep the damn sand out of your socks?
All good stuff - and the big problem is that everyone's feet are different. What works well for one runner may be a disaster for the next.
Here, then, is a very rough rule of thumb (or toe).
If you've been doing a lot of training, then the skin on your feet should already be sufficiently tough. Toughening it up any further with meths or the like will not be necessary - and may, indeed, turn the skin on your foot to shoe-leather. Once your sole loses its suppleness, then it can't expand in the heat, which means it can - literally - peel off like the bottom of an old shoe. It's one hell of a sight, I can tell you.
Toe-nails - nice and short, please. If they're at all long, they'll be battered against the toe of your shoes, and then they'll get bruised, and then they'll fall off.
Shoes - just run in whatever you've been running in. So long as your shoes are fairly robust, you will not need any fancy MdS boot. Get them a size larger - I don't think two sizes is really necessary. (Though if it is necessary, take out the insole.)
Get a cobbler to sew your gaiters into the soles of your shoes.
Sock-wise, go for the Injinji toe-socks - faintly reptilian, but they do the business.
It goes without saying that all this kit needs to be road-tested several times before you get out to the Sahara.
On the flight out to Ouarzazate (pronounced Wazzazatt), keep your shoes in your rucksack. Every race, at least a couple of bags go missing. You can replace everything else, but replacing shoes and gaiters is tricky.
Lastly: if you're getting big blisters on day one, then you've got to do something different. Change your socks. Fiddle around with your shoes. Otherwise the blisters will just get bigger... and bigger.
4. Buy poles
Unless you're a real athlete who's running all the way, then get yourself some walking-poles.
A lot of people are very - very - sniffy about walking-poles. They smack of middle-aged codgers, and beardie-weirdie ramblers, and bracing yomps on the Pennine Way as the rain pours down the back of your neck.
Well... perhaps walking poles aren't the coolest thing to have in the world, but on the MdS they are completely and utterly brilliant.
Because the truth is that despite your best avowed intentions, you're going to be walking a lot of the race. With most of the big hills and the dunes, there is no point whatsoever in trying to run up them. You will be going at exactly the same pace as if you were walking, and you will just be making yourself more knackered. (And you'll be more likely to give yourself blisters. One of the main causes of blisters is sheer, when your feet move sideways, across from your line of travel. This happens most often when you're pelting up or across a dune.)
Walking poles can really help drive you up a hill. With a 12-kilo knapsack on your back, they can take at least 20 per cent of the weight off your feet.
They're also great for going down hill, when some idiot Frenchman barges past and you come within an ace of braining yourself on a rock. (Happened to me in 2012. Boy was I thrilled when I saw him get drummed out of the race two days later.)
And - one last reason to get yourself some poles - they're great when you're completely spent, stumbling along through the middle of the night and banging into every rock in your path. A pair of poles can really keep you on your feet.
Poles take a little getting used to, so have a few practice sessions beforehand. Cycling gloves will stop your hands getting blistered.
But don't buy the lightweight, collapsible poles that fold in on themselves. They're flimsy and expensive - and they snap in half. The telescopic poles are more robust, though lightweight is obviously good.
5. Buy all your kit at home
Before the MdS, I had been reliably informed that if I was missing any kit, then I'd be able to buy it in the special MdS shop at the first bivouac.
Great! I'd be able to buy those special MdS sunglasses, just perfect for sand-storms! I'd be able to buy one of those MdS casquettes, like the French Foreign Legionnaires' kepis! I could gorge myself on MdS gear, the better to swank to all my mates when I got back home to Britain.
And as it turned out...
Well there was indeed an MdS shop at the first bivouac... though by the time I arrived, it had been picked bare.
I ended up buying a single, solitary buff to go round my neck.
I ended up having to run the damn race in my wife's designer sunglasses, which would have looked just great in St Tropez (if I'd been a woman), but somehow looked just a little bizarre on the MdS.
And they were absolutely useless in a sandstorm.
6. Make buddies before you go
The MdS can be a fantastically bonding experience. Life-long friendships can be forged in the crucible of the Sahara.
And there are quite a few fights too.
In the MdS, you'll have eight runners to a tent and for a whole week, you will be living in close proximity to these tent-mates.
Some are going to be good guys; some not so good. Some of them will really get on your wick.
The MdS stretches runners in ways they've never been stretched before. After slogging 24 hours through the desert on the long day, a number of runners will be on quite a short fuse. They'll be ready to blow at almost anything.
You want to scope out possible tent-mates BEFORE you've flown out to Morocco. Of course you'll be making new buddies when you arrive in Ouarzazate, but you won't have a clue what they'll be like when the chips are down. Just because they're affable and they buy you a beer in the bar does not necessarily mean they're going to be great tent-mates.
So: get onto the forums and the web-sites and see if you can hook up with your other runners. Go for a long run with them. See what they're like in the rain when their clothes are sopping. Are they whiners - or are they sunny side up?
Try and tee up at least a couple of tent-mates before you go. Otherwise you'll just be saddled with whoever you happen to meet when you get out to the desert.
In my book on the MdS, The Woman Who Was The Desert Dream, I describe a number of fights in the bivouac - huge fights which blew up over the most footling disagreements. All these fights actually happened. And much worse besides.
7. All the food you need
MdS runners have to carry a minimum of 2,000 calories per day for the race.
This will be the least of your concerns.
There are various different types of food that you'll be carrying.
First of all: the bulky stuff. The breakfasts and the main meals that are going to power you through the race. Breakfast: go for whatever your fancy. Porridge oats are quite popular, as are grain bars, which don't have the hassle of needing hot water. (Though a cup of mint tea, sweet, can be a real pick-me-up in the morning.)
For your main meals, there are various dehydrated packs on offer - spaghetti is supposed to provide the most calories per pound. Go for variety. You can always swap meals with your tent-mates. One idiot I knew [Hi Dougie!] took out six packs of spaghetti. Without even trying them. After his first supper, Dougie decided that he hated dehydrated spaghetti.
Decant all the meals out of their pouches into Jiffy bags. This will save 300 grammes.
A lot of runners take along puddings. Most of these puddings were binned on the second day. You won't need them and that's because...
When you're running, you'll be eating a ton of sweet stuff. Little sports beans and various powders, so that by the time you're done for the day, the very last thing you'll feel like eating is MORE sweet stuff.
The powders that work quite well are Peronin, which, when added to water, turns into a custard-gloop. At lunch-time, you can down 500 calories in under a minute.
At the end of the race, you'll need a recovery powder - something like Rego is fine. This needs to be taken in the Golden Hour - the hour directly after you've stopped running. Food that is eaten in the Golden Hour is much, much more effective at helping your body recover. (And, while I'm on the Golden Hour, put your feet up. Lie down and raise your feet a foot off the ground for at least for 20 minutes. It is bliss - and it drains all the gunk out of your legs.) These two single things - putting your feet up and downing a recovery drink - are far and away the best things you can do to get your body in good shape for the next stage.
You'll also need little nibbly things for while you're actually running. Sports beans are not bad. (Like jelly-beans only four times the price.) Some runners had jelly-babies. Chew away on these sports beans little and often - I'd have a sports bean every ten minutes.
Gels are pretty good if you're running a marathon, but are a bit weighty for the MdS. Take along a couple - with caffeine - for when you're really up against it.
You'll also need a couple of tubes of electrolyte tablets to replace all the salts that you'll be sweating out. (One day I drank 11 litres of water - and never once needed to stop for a pee.) Get a variety of flavours, though it won't matter much as you'll soon be sick of them.
The MdS Commissaires will provide you with a small bag of salt tablets. When you're running, you want to take a couple of salt tablets on the hour, every hour. (By the way - you swallow them whole. They do not dissolve in water.)
8. The luxuries
In the evenings on the MdS, I liked to mooch about the bivouac with my great mate Dougie. The bivouac comprises two circles of rickety black tents, one inside the other, about 200 yards diameter. We would walk on the track between the two circles of tents. It was like staring in through all these front parlour windows.
One evening we saw a Frenchman standing by his fire. (The French runners always have actual fires outside their tents - very classy). He was wearing just shorts and a T-shirt and had long Tarzan-like hair. He was drinking tea.
For the first and only time on the MdS, I experienced genuine envy.
He was drinking his tea out of a glass made of the most delicate cut-crystal. I can even remember its rainbow twinkle in the dusk glow of the firelight.
It must have been quite a caper carrying this cut-crystal glass around with him, let alone making sure that it didn't get smashed. But one little luxury can be a real pick-me-up. It can remind you that while all about you is dirt and filth, there is still one thing in your life which is clean and beautiful and pristine.
Other little luxuries? I had a book - a good thick one, The Cruel Sea, weighing in at 300 grammes. But that's because I love reading. In the evening, when everyone else has gone to sleep at 7.30pm, there is nothing finer than to be reading in the snug of your tent as the stars twinkle and guy-ropes are flapping in the wind.
Most runners' little luxury item tends to be a bit of food. Something like a packet of Fruit Gums or a Peperami. One guy took a bottle of lager! As if you'd want to drink tepid lager in the desert!
I think your best bet would be a bottle of Tabasco. Put a few dashes of that on your spaghetti carbonara and it would soon take your mind off your seething blisters.
9. Treat your sponsors
The MdS will probably be the toughest challenge you've ever experienced, so it would be churlish not to use it as a platform to raise money for your favourite charity.
Your friends may well be suffering from charity fatigue after being tapped up by worthies who are running Ten Ks and half-marathons.
But they won't know many people who are running the MdS.
It's such an unusual type of challenge that you can raise a lot of money.
Though here's a tip.
It's no fun whatsoever just sending out a round-robin email to all your mates asking them to sign up to your "just giving" account.
What is fun is to lay on a film night.
Dougie and I booked the biggest screen in Edinburgh's Dominion cinema - well over 250 seats. Only cost about £700. We laid on a few cases of wine as well and charged £15-a-head - though many of our friends gave much more. Everyone, without exception, absolutely loved it.
But what film to show?
We picked Casablanca. A classic. Suitably deserty feel. Plus: although most people have seen bits of the film and know a few of the lines, very few people have seen it from start to finish. (Though it is such a fantastic film that any human being on this earth would be more than delighted to see it again.)
One more thought: if you know that over £7,000 worth of sponsorship is riding on you completing the MdS, it rather helps to concentrate the mind during that squeaky-bottom moment when you're thinking of pulling out.
10. Line up the next dream
For a lot of runners, completing the MdS is one of the greatest achievements of their entire life.
You should the tears at the finish-line! I even saw a guy get down onto his knees and propose to his girlfriend. Everyone was crying!
And then, later, as you shower and as you celebrate in the bar, you will be engulfed by wave after wave of euphoria. You've done it! You've knocked the bastard off! You don't have to run another step! You can eat decent food, and have a comfy bed, and will never, ever have to put yourself through such an ordeal again.
And this intoxicating euphoria will continue the next day.
And the next day.
And usually the next day after that.
But after a week, when you're back home, and it's raining outside, and you've got nothing left to train for, then you can get knocked back with quite a bad dose of the glums. It's only when you've achieved your dream that you realise that most of the fun was actually the journey - all those months of preparation you put in to get you ready for the race.
There is one great antidote.
Before you've even set foot in Morocco, you want to have lined up the next project. The next lunatic dream.
You are not going to rest on your MdS laurels for even a single day.
The best challenges will not involve any more running. You'll already have well and truly ticked that running box. For preference, it will involve something that you're completely useless at.
Me? I used to be really pathetic at swimming. Couldn't even manage 75 metres of freestyle before I was spent.
So for that first week after I got back from the MdS, I'd already lined up a course of lessons at my local pool.
And had also signed up to swim the Hellespont.
And then failed to swim the Hellespont.
But that's all fine because that Hellespont swim has now just become another work in progress.
Although the MdS is a magnificent achievement, the toughest of the tough, we still have to find some fresh windmill to tilt at, some giddy new peak to climb.
We are like sharks - we have to keep moving forward or else we die.