The Marathon des Sables (MDS) is a six-stage, self-supported foot race across the Sahara Desert in southern Morocco, held annually in early April. Approximately 250 km total, broken into stages of 30–80 km each, including a 80–90 km "long stage" that takes most runners 12–24 hours. Runners carry all their food, sleeping gear, and required equipment for the week in a single pack — only water and tents are provided.

The stage format

The race shifts location every year but the rhythm is consistent:

  • Stage 1: ~30 km. Easing in. Often dunes-heavy.
  • Stage 2: ~38 km. The first big day.
  • Stage 3: ~33 km. Mid-week grind.
  • Stage 4: ~80–90 km. The long stage. 36-hour cutoff. Runners finish anywhere from 12 hours to overnight + the next day.
  • Stage 5 (rest day): No racing. Recovery in the bivouac.
  • Stage 6: ~42 km marathon stage to the finish line.
  • Stage 7: A short charity stage.

By the numbers

  • Total distance: ~250 km / 155 miles (varies year to year)
  • Surface: dunes, hammada (rocky plateau), djebels (rocky hills), dry riverbeds
  • Heat: 35–50°C (95–122°F) daytime; 5–15°C (40–59°F) nighttime
  • Pack weight: 6.5–8 kg minimum required, plus daily water carried (1.5 L)
  • Required calories: 14,000 kcal (2,000/day) per runner provided by themselves
  • Water: rationed, 11–14 L per stage handed out at checkpoints
  • Field size: ~1,300 runners
  • Date: early April

Self-supported, exactly

"Self-supported" at MDS means you carry every calorie you'll consume for seven days. Race organization provides:

  • Open-sided Berber tents (8 runners per tent) at each bivouac
  • Daily water rations (handed out at checkpoints and bivouac)
  • Course markings + cutoff enforcement
  • Medical (basic, but real — IV fluids and emergency evac available)

You provide everything else: sleeping bag, sleeping mat, headlamp, stove, spare batteries, food, salt, anti-chafe, and the compulsory items on the kit list (compass, signal mirror, anti-venom pump, whistle, etc.). The race weighs your pack at the start; under 6.5 kg and you're disqualified.

Food strategy — the hardest puzzle

You need 14,000 kcal in your pack. You need that pack to weigh under 8 kg total once you add the mandatory kit. That math forces calorie density:

  • Freeze-dried dinners: Mountain House / Real Turmat / Trek 'n Eat (~600 kcal/100g). Five dinners + one rest-day dinner.
  • Breakfasts: Granola in a ziploc with milk powder. Add water and eat cold or hot.
  • Race fuel: Maurten gels, Spring Energy, Tailwind powder, salted potato chips, dehydrated mango.
  • Recovery: Whey protein powder, electrolyte tabs, multivitamin.
  • Comfort food: One small treat per day — a square of dark chocolate, dried fig, salami stick. Morale food matters more than expected.

Most veterans target 9,000–10,000 actual kcal carried (under the official 14,000 minimum on a calorie-per-day basis) and accept the deficit. You will lose 4–8 lbs of body weight over the week regardless.

Gear list (the essentials)

  • Pack: WAA Ultra Bag 20L or OMM Phantom 20 — designed specifically for stage races. ~600g.
  • Shoes: Half-size up. Dunes pour sand into normal-fit shoes by mile 5. Hoka Speedgoat Mid GTX, Altra Olympus, or Salomon Sense Ride.
  • Gaiters: Mandatory custom desert gaiters. Get them sewn directly onto your shoes by Raidlight or DIY with velcro. Without them, sand fills your shoes within 2 km of the first dune.
  • Sleeping bag: Sea to Summit Spark Sp1 or Western Mountaineering HighLite — 400–500g, rated to 40°F. The Sahara nights get colder than people expect.
  • Sleeping mat: Therm-a-Rest NeoAir XLite (small) or just a foam mat. Optional but recommended.
  • Sun protection: Long-sleeve UV shirt, neck buff, wide-brim sun hat with neck cape (Sunday Afternoons Adventure), sunglasses with side coverage.
  • Headlamp: Petzl ACTIK Core (350g, two lithium batteries). Backup hand torch.
  • Stove: Esbit hexamine cube stove + 24 cubes. Boils water for freeze-dried meals. ~150g total.

How to enter

MDS does not use a lottery. Registration is first-come, first-served, and opens roughly 18 months before the race. The English-language slots fill within hours; the French slots within minutes. Plan to register the moment registration opens.

Cost is significant — €4,500–5,500 entry fee plus flights to Ouarzazate (Morocco), gear (~$1,500 if starting from scratch), and food. A first MDS typically costs $7,000–10,000 all-in.

Pacing strategy

Forget pace. MDS is run on heat management. Most runners walk 60–80% of the daily distance, run only the cooler morning/evening hours, and shelter in the limited shade of checkpoints during the afternoon peak.

Hydration is rationed (1.5 L per checkpoint, 4–5 checkpoints per stage = 7–10 L per stage including bivouac). You cannot drink more — you cannot get more. Sip early in the stage; ration toward the end.

Pack weight matters more than fitness. A runner with average ultra fitness and a 6.6 kg pack will outperform a fitter runner with an 8 kg pack — every gram matters across 250 km in dunes.

The bivouac experience

You sleep on the ground in an open-sided Berber tent with seven other runners. There is no shower for seven days. There are pit-style toilets. There is a daily race briefing in French (with English summary). Tent-mates become close — many MDS finishers describe the bivouac community as the most memorable part of the race.

The MDS reputation

MDS is famous, photogenic, and accessible — which means the field is a mix of experienced ultrarunners and ambitious first-timers, the latter often arriving under-trained. The DNF rate hovers around 8–12%. The race is less brutally hard than the marketing suggests, but harder logistically than any single-stage ultra. The challenge is mostly heat, sand, food rationing, and seven days of cumulative fatigue — not any single moment of suffering.

Most finishers describe it as transformative. Some come back. Many never run sand again.

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