How To Fuel For MDS 2019!

Disclaimer: Although between us we have completed many multi-stage races & consequently have a great interest in nutrition, we are not a qualified dieticians. This article is aimed at helping you understand how you can structure your food, give you ideas for what to take and what factors to consider. For more personalised suggestions Elisabet offers 1-1 consultations

Among the many questions we get receive about MDS in store, we are frequently asked what should I eat for a self-sufficient multi-stage race such as the Marathon des Sables. The reality I that there is not one magic answer as everyone has individual needs, however, we wanted to provide some thoughts on the topic that will be able to point you in the right direction.

There are two categories of self-sufficient multi-stage races when it comes to nutrition: the completely self-sufficient race where you carry all your food and the semi self-sufficient race where you bring your own food but the organisers transport it for you. In the first scenario weight is a very important factor. The second scenario you may still have a weight or volume restriction on your gear which could impact your food choices but you have some more flexibility. We will be focusing on the completely self-sufficient race type in this article and specifically the Marathon des Sables.

How to structure your food

It is important to understand what kind of racer you are before you start preparing anything. This is not only for food planning purposes but also for your race kit & equipment. What we mean by this is primarily how fast you intend to complete the race.  For reference we have included one of Elisabet’s presentation references bellow:


As you can see, the time you spend on the course vs in camp will dictate how you should plan your food. Of course things can change during the course of the race but figure out where you think you’ll fit or what your goal is and you’ll have a clear starting point.

Fast Runner
You are running fast and will finish each stage by lunch time or early afternoon. Due to the higher intensity it is likely that you will rely more on carbohydrates than a slower competitor. It is unlikely that you will have time to chew on bars, and for example nuts will not give you enough carbohydrates, thus it’ worth considering gels if they are something you normally take on.

We suggest you structure your food for a typical race day as follows:

  1. Breakfast
  2. Race Fuel for the stage
  3. Recovery Snack (shake for example)
  4. 2nd Recovery Snack
  5. Dinner


Mid Pack
This category encompasses a large range of competitors so if you feel you are more towards the front or the back, look at those respective categories too. You will be a mix of running and walking throughout the race, but you are working at a reasonably high intensity due to the extreme conditions of the environment you are in. The walking breaks will allow you to take on more solid fuel during the stage so you are in a better position to mix sources of fuel such as powder, gels, bars, nuts, sweets and other snacks. You will finish in the afternoon and have some time available before dinner.

We suggest you structure your food for a typical race day as follows:

  1. Breakfast
  2. Race Fuel for the stage
  3. Recovery Snack (shake for example)
  4. Dinner


If you are planning to walk all or most of the race finishing within the cut-off times, you’ll have little time in camp to eat before it’s bed time. As you’ll be working at a lower intensity throughout you can rely more on fat and less on carbohydrates for fuel. You can also take on solid food sources such as bars, nuts, pepperami etc. during the stage as you are not running fast.

We suggest you structure your food for a typical race day as follows:

  1. Breakfast
  2. Race fuel for the stage
  3. Dinner

Race Structure

Once you have figured out what type of competitor you are likely to be, you also need to consider how you’ll structure of the race. The long stage and the rest day will require a different food plans.


The long stage & the rest day
For the walker, the long stage is typically completed over two days with a break at a mid-point check point between. A normal cut-off time would be around 35 hours. From that perspective your food plan for the long stage may be fairly similar to two normal days combined and can just be treated as such, perhaps with a few more walking snacks for good measure.

For the racer at the front the long stage may take anything between 8-12 hours. Therefore, the structure for this day would involve something like breakfast, roughly double the amount of race fuel compared to a more standard day and then dinner. The recovery shake and the recovery snack can be replaced with additional race fuel considering that your rest day that follows you probably want lunch rather than running snacks!

The mid-packer may decide to push on through the long stage in one go or to take a break of a few hours to get some sleep or cook up a meal. Plan your food accordingly. We recommend that no matter what time you finish this stage, even if it is 3am, that you eat something before you go to sleep to benefit your recovery.

The last day
The final day in MDS is a non-competitive but compulsory charity stage. As the race is effectively over your performance doesn’t matter on this day. As you still need to carry 2000 kcal for this day we suggest that you minimise your weight by opting for quality high calorie foods rather tan quantity.


What food should you take?

This is of course a very personal choice based on your specific dietary needs & requirements. Hopefully with the structure outlined previously you should be able to select foods that you believe will work for you. However, be sure to test them carefully in training to avoid surprises during the race itself!

We have given some examples below of some food options that are low in weight for the energy they provide to help you pick things you may want to try or to spark ideas.

Please bear in mind that taste & appetite can change in an extreme environment so variety is good. Elisabet normally finds that over the course of the long stage her appetite changes and in the second half she requires more savoury and more solid fuel. Therefore would normally make up a pack for the first half and one for the second which are slightly different with the second containing more fat, protein and savoury foods and the first more carbohydrate.


B = Breakfast, D = Dinner, L= Lunch, R = Race Fuel, RE = Recovery, C = Complement to dinner or breakfast or a general snack


How much food should you take?

The minimum requirement is normally 2000 kcal per day (14000 kcal in total), but what is right for you? Take a 50kg female and 90kg male. They will have very different requirements for energy intake and also different ability to carry the same weight in their backpack. No matter how much food you take you will likely be in energy deficit. It is simply not realistic to carry all the calories you will expend during the race so you will probably lose some weight.

One way of getting some estimation of your energy expenditure can be to take your basal metabolic rate (BMR) plus the energy you are likely to expend during a stage in MDS.

Let’s use an example of a 40 year-old male, who is 175 cm tall and weighs 70kg. His BMR is 1634 kcal, so he will expend this much energy if doing nothing for the entire day. If he engaged in very light activity the energy expenditure would be 1961 kcal. We will assume this to be a reasonable energy expenditure for completing basic activities in race camp (personal admin, small amount of walking).

Energy expenditure for running has been estimated to be in the region of 1kcal/kg bodyweight / km in several studies (Ref 1). This applies for flat running without wind resistance. A typical stage of the MDS is 40km and so for the sample male runner as above, the very minimum energy expenditure required to complete such a stage would be 2800 kcal (speed is not relevant). Other factors such as carrying a backpack, wind resistance, variations in incline and heat would then also add to this energy requirement but I have not taken this into account for simplicity. For walkers, the energy expenditure is lower and it is more economical to walk as long as speed is kept at below 8km/hour. For a walker who does 4km/hour (the most economical walking speed) the corresponding energy expenditure is about half that of running (Ref 2).

From this follows that the very minimum energy expenditure for our 70kg 40 year-old male runner is 4761 kcal (1961 + 2800) per day for a typical stage.

Recommendations are to take in 8-12g carbohydrate for strenuous exercise for 4-5 hours / day (Ref 3,4). One gram of carbohydrate yields 3.87 kcal so 12 grams of carbohydrate per kg bodyweight for our sample man would correspond to 3250 kcal. (Higher value selected due to most people likely to be out for longer than 4-5 hours / day).

Protein is vital for repair and recovery of muscles. Requirements for athletes is 0.25g / kg per kg bodyweight 3-6 times per day (Ref 3). If we therefore assumed 1.5g of protein per kg bodyweight in total due to the extreme nature of the event, and 1g of protein yields 4 kcal this provides 420 kcal.

Recommendations for fat intake vary and high fat diets are subject to plenty of interest at the moment. However, at this point I am trying to illustrate energy requirements as a whole and not where that energy comes from so if as an example I take Renee McGregor’s general recommendation of 1 g of fat per kg bodyweight, probably on the low side given the extreme nature of the event (Ref 3), this would (with 1g fat corresponding to 9kcal) result in 630 kcal from fat.

Adding all of this up we get to 4300 kcal total for a 70kg, 175cm, 40 year-old man.


These attempts at roughly estimating energy requirements for a typical MDS stage illustrates the point that the minimum calorie requirement of 2000 per day will result in a significant energy deficit for our sample person, but for this person to carry the total amount of energy required would result in a far too heavy backpack. Therefore, finding some middle ground seems reasonable and relying on your body’s fat reserves to cover the rest.

We would suggest that you try to consider what a reasonably energy expenditure might be for you. Take in the region of 1-1.5 gram protein per kg bodyweight and then distribute the remaining calories between fat and carbohydrates based on your own needs and requirements. For example, if you are well fat adapted or intend to complete the race at lower intensity as a walker you may want a higher percentage of calories from fat. If you are racing faster you probably need more carbohydrates to sustain your pace.

One portion of your protein should be as part of your recovery when you finish the stage. Recovery recommendations is to digest a mix of fast release carbohydrates (1-1.2g per kg bodyweight) and easily digestible protein (0.25g per kg bodyweight) within 15-20 minutes of finishing the activity (Ref 3).

Keep it simple

If you found all of this incredibly complicated, there is a simpler approach to building your race menu.

Lay out the food you are thinking about taking, organising it into the different “meals”. Look at it to see if it seems reasonable based on what you normally eat. Test a day’s menu in training when you are doing long run or hike, or maybe over two days back-to-back. Then make adjustments. Pick foods that you know work for you. You will still need to know how many calories you are taking as you need to be able to prove that you have the minimum amount specified, so summarise the values on the labels and make a note of what you have per day.

Below is an example of what a menu for a day might look like.


How to avoid common pitfalls

 No variety of foods
As we already mentioned its not be uncommon for your taste to change in the desert. Many people find they want spicier food and that they crave different things. A variety of foods can help keep it interesting and ensure you eat sufficiently.

Sole focus on kcal per 100g
The maximum amount of kcal per 100g you can get is 900 for pure fat. Therefore, foods that are very high in fat content give you more energy for the weight. However, you need to consider how you’ll perform on the food you take. Don’t stare yourself blind on how many kcal you can squeeze out of 100g, but ensure that the food will be something you know you can digest during exercise in extreme heat.

Not testing food in training
Try to plan your food in advance and test it during a training race or in training runs. How well do you run on intended breakfast? Will your total intended kcal per day be the right amount? Can you stomach luke warm gels? How dry might an energy bar taste in the desert? Will you be able to rehydrate noodles in cold water? Try before you go to the race.

In summary:

  • Figure out what type of racer you are and structure your accordingly for an individual day.
  • Understand potential exceptions to the standard race pattern, e.g. long stage, rest day and the last day which in MDS in non-competitive but still has a compulsory calorie requirement.
  • Understand your total energy requirement either by making calculations or by composing a realistic selection of food for one day that looks right.
  • Select the food that you feel will work for you
  • Consider whether it will suit you to repackage any food in order to save weight or volume
  • Package your food in individual day bags to facilitate admin
  • Label all your food with the calories if not labelled already
  • Decide on your cooking solution
  • Test your food in training


(1) Running Speed and the Energy Costs of Running, C. Harris et. al., Journal of Exercise Physiology Online, Volume 6 Number 3 August 2003

(2) Energy Cost of Running, R. Margaria et. al., Journal of Applied Physiology, 

(3) Training Food: Get the Fuel You Need to Achieve Your Goals Before During And After Exercise, R. McGregor, Nourish, April 2015


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