When we tell people we are doing the Marathon des Sables, the first question is usually "the one where you run 250 km with everything on your back?" That is the MDS Legendary. The same organisers also run the MDS Ultra and the MDS Trek on the same ground. We are doing the MDS Trek Morocco: shorter stages, supported, and still a race against the clock and the sand.

The format

Five timed stages across six days in the Sahara, in the Errachidia province of Morocco near Merzouga, with a rest day in the middle. You pick a long course or a short course. We picked the long one, which is 120 kilometers each. Every stage is timed and every runner carries a GPS beacon, so the organisers know where you are, and so do you, through the live tracker.

It is a run and a walk. Some people run every kilometer. Across the MDS races most people run a fifth of the distance or more, and how much depends on the sand: firm ground and gravel you run, soft dunes you mostly walk because running them costs more than it gains. Aaron plans to run every stretch the ground allows.

It is supported, not self sufficient. That means water at the checkpoints, a shared tent in the bivouac each night, and meals provided. You still carry your own pack, your own safety kit, and your own feet.

The week

Sunday October 11: bus from Ouarzazate to the bivouac, about six hours.
Monday October 12: technical and medical checks. No racing yet.
Tuesday October 13: Stage 1.
Wednesday October 14: Stage 2.
Thursday October 15: Stage 3, day 1, which ends at Star Night, a night out under the open sky.
Friday October 16: Stage 3, day 2.
Saturday October 17: rest day.
Sunday October 18: the final stage and the finish line.

What the checks are for

On Monday the organisers inspect every pack against a mandatory list: water capacity, a survival blanket, a headlamp, a whistle, a signalling mirror, sun cream, antiseptic, safety pins, a lighter, 100 euros and your passport. Some of it has to be on you during every stage, because they do random bag checks on the course. A signed medical certificate is required to start.

Why this one

We needed something hard enough to be worth sponsoring and safe enough that two people in their fifties and sixties could finish it. A hundred and twenty kilometers of sand and rock in the heat, with a pack, qualifies. And the kilometer makes a clean unit. A dollar a kilometer is $120 for one of us or $240 for both, and all of it goes to the house in Nepal.

If you want to follow along, the tracker switches on with the first stage. Bibs 387 and 388, tent 238.