The Marathon des Sables® is the legendary race, the extreme challenge where managing effort, gear, and mindset is crucial since you have to run self-sufficient in food under temperatures that can exceed 50°C.
We’re lucky to share advice from Mérile ROBERT, a Marathon des Sables® regular with seven participations, including two podiums in 2018 and 2021. Thanks to his experience in prestigious Ultra Trails like the UTMB®, he also won the Grand to Grand Ultra in the US in 2022. For the MDS®, he fine-tuned his gear and prep to compete with the Moroccan elite.
If you take part in the 2025 edition, you might get the chance to meet him, this time alongside a joëlette team. Don’t hesitate to go say hi!
Mérile, what are your training secrets for the Marathon des Sables®?
"Preparation for the Marathon des Sables® mainly relies on progressively increasing training distances, favoring flat terrain. The main goal is to optimize your running economy to reduce effort with every step. This ability improves by exposing yourself directly to the race's demands."
The 2 key points of training:
Build your endurance and resilience
Endurance is essential in the preparation. You need to gradually increase the training load by adding long outings with a 6 to 8 kg backpack. The goal: get your body used to effort under load.
The preparation must also replicate the specific demands of the race:
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- Long repeated efforts over several days.
- Heat and monotony of the course. You have to get used to moving along long straight lines, like those of a canal, to prepare mentally.
- Long repeated efforts over several days.
A gradual build-up
A 7 to 8 month prep cycle is necessary, with a gradual build-up. From December, you need to be able to run 50 to 60 km per week.
Twice-a-day sessions are a good strategy to increase volume and improve recovery. The body adapts to hold the distance. At the Marathon des Sables®, recovering is just as crucial as moving forward.
And the sand, how do you handle those brutal dune sections?
"Contrary to what you might think, sand only makes up 20 to 30% of the course. The rest is hard tracks, rocky paths, and uneven ground. So it’s essential to vary your training terrains to get used to less regular foot placements and develop a good reading of the ground. Avoid running only on asphalt or overly maintained trails."
What do you think are the 3 key points of race management?
"Beyond training volume, it’s essential to acquire specific skills:
- Learn to manage your effort and run/walk at the race’s average paces.
- Adopt a conservation mindset, making sure to preserve your resources.
- Get used to alternating running and walking efficiently, especially during long run-hike sessions."
Managing boredom and staying focused
The Marathon des Sables® will test your mind: endless straight lines, blazing sun, endless landscapes. In those moments, boredom can quickly settle in and kill your motivation.
To fight it, bet on simple but effective actions. Use your nutrition protocol as a guide: hydrate and feed yourself regularly. Set reminders on your watch so you don’t have to think about it. Every sip of water, every bite becomes a mini-goal to pace your race and keep your mind busy.
By breaking these long stretches into smaller stages, you'll keep on track without letting monotony overwhelm you.
What do you do to optimize recovery between each stage?
"Recovery starts the moment you cross the finish line and plays a key role in being able to set off again each day in the best conditions."
Post-effort hydration and nutrition
The water provided at camp is usually enough to properly rehydrate you after the effort. But to combine recovery and pleasure, think about bringing some tea bags or dehydrated soup. Light and handy, they bring real comfort day after day.
Another must-have: the recovery drink. Packed with carbs, proteins, sodium, minerals, and vitamins, it helps you recharge your energy and muscle reserves after hours of effort under scorching heat.
Rest and active recovery
Rest, yes, but don’t neglect active recovery. After the finish, walking a few minutes boosts blood flow and helps recovery. Also think about compression socks to reduce muscle fatigue and bounce back better the next day.
The MDS® is a self-supported race, how do you advise managing food and nutrition?
"One of the most common mistakes is to start with too much food out of fear of running out."
Prevent dehydration to better face the desert
In the extreme conditions of the Marathon des Sables, hydration is a must. Waiting until you’re thirsty? A costly mistake. Dehydration limits performance and often hits too late. To avoid it, drink regularly, even in small sips. Good water balance is your guarantee to last the distance and better handle the desert’s crushing heat.
"During the race, I take neutral-flavored sports drinks, dilute them a lot, and alternate with plain water. At the bivouac, I also have a recovery drink. It’s essential to restore levels after several hours of effort in a hot, dry environment."
Optimal freeze-dried nutrition
"Freeze-dried meals offer an optimal weight/calorie ratio and are easy to prepare at the bivouac. To avoid digestive issues, better skip spicy dishes. One of the most common mistakes is to start with too much food out of fear of running out. In reality, feeling hungry is normal but temporary. The key is to ensure an overall sufficient energy intake throughout the event."
The Marathon des Sables® organization recently updated the mandatory gear list by adding 14 bouillon cubes. This new measure aims to ensure mineral salt intake and ease recovery, especially in a hot and demanding environment. These cubes will be key to maintaining hydration and electrolyte balance throughout the race. So make sure to include this new requirement in your gear to be fully ready.
Top up your intake with energy snacks
Alongside main dishes, some foods help improve eating comfort and provide essential nutrients:
- Jerky: rich in protein, it helps recovery and adds flavor.
- Salted nuts (almonds, cashews…): a source of energy, good fats, and salt, essential to compensate for losses through sweating.
- Freeze-dried soups: they bring a comforting effect and help with hydration after effort.
- Mérile sometimes tops up her meals with vermicelli pasta, a simple way to adjust portions based on her energy needs.
Raidlight teamed up with MX3-Nutrition to create freeze-dried nutrition packs. The 7-day desert pack will provide you with all the rations needed to last the entire duration of your race.
Discover our meal plan specially designed for a 7-day desert race by clicking on this link.
In your opinion, are trail poles useful for the MDS®?
"During the Marathon des Sables®, 60% of finishers move at speeds between 7 km/h and 4.5 km/h, while 26% go slower than 4.5 km/h. These speeds clearly show the importance of walking in this race, just as much as running. That's why it's essential to work on Nordic walking technique. This method not only helps manage effort on tough terrain but also reduces fatigue by optimizing the use of your upper body and poles to maintain a good pace throughout the race."
The Raidlight desert guide: the bible for desert races.
Future participant, to best prepare you for races as demanding as the Marathon des Sables®, Raidlight offers you a complete guide dedicated to desert races.
As desert specialists for 25 years, we designed this guide to support you and share all our practical advice: preparation and organization of your trail bag, nutrition, gear, training, life at the bivouac… This guide is made to meet the specific needs of trail runners, whether you're a beginner or experienced.
Mérile also shares other practical tips, especially about gear.
Download our advice guide for free
Also discover a series of articles on our blog: training plans, tips for choosing your trail shoes, advice for preparing and organizing your trail bag…
- How to choose your shoes for the Marathon des Sables®, the Half Marathon des Sables®, or the Raidlight Desert Trophy?
- What gear for the Marathon des Sables®, the Half Marathon des Sables®, or the Raidlight Desert Trophy?
- How to prepare and organize your bag for the Marathon des Sables® or the Raidlight Desert Trophy?
By following these tips, you'll be ready to tackle the Marathon des Sables® in the best conditions. Rigorous preparation, the right gear, and a well-thought-out strategy will make all the difference on the ground. Stay focused, manage your effort, and take care of every detail of your preparation. Good race, and may this adventure be an unforgettable experience that stays with you forever!
