The Marathon des Sables® is a mythical event, an extreme challenge where managing your effort, your equipment and your mental state is essential, as you have to run self-sufficiently in temperatures that can exceed 50°C.
We are lucky enough to be able to share with you the advice of Mérile ROBERT, a regular at the Marathon des Sables® with seven participations, including two podium finishes in 2018 and 2021. Thanks to his experience on prestigious Ultra Trails, such as the UTMB®, he has also won the Grand to Grand Ultra in the United States in 2022. For the MDS, he has fine-tuned his equipment and preparation to compete with the Moroccan elite.
If you're taking part in the 2025 edition, you might just come across him, this time alongside a joëlette team. Don't hesitate to go and meet him!
Mérile, what are your training secrets for the Marathon des Sables?
‘Preparation for the Marathon des Sables® is mainly based on a gradual increase in training distances, with the emphasis on flat terrain. The main objective is to optimise your running economy to reduce the effort required with each step. This ability is perfected by exposing yourself directly to the demands of the event’.
The 2 key training points :
1. Build endurance and stamina
Endurance is essential in preparation. You need to gradually increase the training load by adding long outings with a 6-8kg bag. The aim is to get your body used to working under load.
Preparation must also reflect the specific characteristics of the event:
Long efforts repeated over several days.
Heat and monotony of the course. You need to get used to riding in long straight lines, like those of a canal, to prepare yourself mentally.
2. A gradual build-up
A preparation cycle of 7 to 8 months is necessary, with a gradual build-up. From December onwards, you should be able to run 50 to 60 km a week.
Running twice a day is a good strategy for increasing volume and improving recovery. In this way, the body adapts to cope with the distance. In the Marathon des Sables®, recovering is just as crucial as moving forward.
‘Recovery starts as soon as you cross the finish line and plays a key role in ensuring that you can set off again each day in the best possible condition.
What about the sand, how do you manage the terrible dune crossings?
‘Contrary to what you might think, sand only accounts for 20-30% of the route. The rest is hard tracks, stony paths and uneven ground. So it's essential to vary your training areas to get used to less regular footing and develop a good feel for the ground. Avoid running solely on tarmac or overgroomed paths.
In your opinion, what are the 3 key points in race management?
‘Over and above the volume of training, it's essential to acquire specific skills:
Learning to manage your effort and to run/walk at average race pace.
Adopting a spirit of conservation, taking care to spare your resources.
Getting used to alternating effectively between running and walking, particularly during long outings.
Managing boredom and staying focused
The Marathon des Sables® will put your mind to the test: endless straights, blazing sun, endless landscapes. At times like these, boredom can quickly set in and dampen your motivation.
To counter this, take simple but effective action. Use your dietary protocol as a benchmark: hydrate and eat regularly. Set reminders on your watch so you don't have to think about it. Every sip of water, every mouthful becomes a mini-objective to punctuate your run and occupy your mind.
By breaking up these long stretches into smaller stages, you'll stay on course without becoming overwhelmed by monotony.
What are you doing to optimise recovery between each stage?
‘Recovery starts as soon as you cross the finish line and plays a key role in ensuring that you can set off again each day in the best possible condition.
Post-race hydration and nutrition
The water provided at the camp is generally enough to rehydrate you after the effort. But to combine recovery with pleasure, remember to take along some tea bags or dehydrated soup. Lightweight and practical, they make everyday life much easier.
Another essential: the recovery drink. Rich in carbohydrates, proteins, sodium, minerals and vitamins, it helps you recharge your energy and muscle reserves after hours of exertion in the sweltering heat.
Rest and active recovery
Rest, yes, but don't neglect active recovery. After the finish line, take a few minutes' walk to stimulate blood circulation and aid recovery. And don't forget compression socks to reduce muscle fatigue and help you get back on track the next day.
The MDS is an autonomous race. How do you advise managing food and nutrition?
‘One of the most common mistakes is to set off with too much food for fear of running out.
Preventing dehydration to cope better with the desert
In the extreme conditions of the Marathon des Sables, hydration is a necessity. Waiting until you're thirsty? That can be a costly mistake. Dehydration limits performance and often strikes too late. To avoid it, drink regularly, even in small sips. A good fluid balance ensures that you can go the distance and cope better with the scorching desert heat.
‘During the race, I take neutral-tasting effort drinks, which I dilute a lot and alternate with clear water. On the bivouac, I also have a recovery drink. It's essential for replenishing levels after several hours of exertion in a hot, dry environment.
Optimum freeze-dried nutrition
‘Freeze-dried meals offer an optimal weight/calorie ratio and are easy to prepare on the bivouac. To avoid digestive problems, it's best to avoid spicy dishes. One of the most common mistakes is to set off with too much food for fear of running out. In reality, the feeling of hunger is normal, but temporary. The most important thing is to ensure that you get enough energy overall for the whole event.
The Marathon des Sables® organisers have recently updated the list of compulsory equipment, adding 14 bouillon cubes. The aim of this new measure is to guarantee a supply of mineral salts and to facilitate recovery, particularly in a hot and demanding environment. These cubes will be a key element in maintaining hydration and electrolyte balance throughout the event. So make sure you include this new requirement in your equipment to be perfectly prepared.
Supplement your intake with energy snacks
As a supplement to your main dishes, there are certain foods that can improve your comfort level and provide essential nutrients:
- Dried meat: rich in protein, it helps recovery and adds flavour.
- Salted oilseeds (almonds, cashew nuts, etc.): a source of energy, good fats and salt, essential for compensating for sweat-related losses.
- Freeze-dried soups: comforting and hydrating after exercise.
- Mérile sometimes supplements her meals with vermicelli pasta, a simple solution for adjusting portions according to energy needs.
Raidlight has teamed up with MX3-Nutrition to design freeze-dried nutrition packs. The 7-day desert pack will provide you with all the rations you need to last the duration of your race.
Click on this link to find out more about our food plan designed specifically for a 7-day desert race.
Do you think trail poles are useful for the MDS?
"During the Marathon des Sables®, 60% of finishers progress at a speed of between 7 km/h and 4.5 km/h, while 26% progress at less than 4.5 km/h. These speeds clearly show the importance of walking in this event, in the same way as running. That's why it's essential to work on your Nordic walking technique. This method not only allows you to manage your effort on difficult terrain, but also to reduce fatigue by optimising the use of the upper body and the poles to maintain a good speed throughout the event."
By applying these tips, you'll be ready to tackle the Marathon des Sables® in the best possible conditions. Rigorous preparation, the right equipment and a well thought-out strategy will make all the difference on the ground. Stay focused, manage your effort and every detail of your preparation with care. Have a good race, and may this adventure be an unforgettable experience that will leave a lasting impression on you!
