Running an Ultra Marathon


Endurance athletes of all abilities tackle such events for all kinds of reasons, through some of the most extreme and hostile environments on the planet. There are many event organisers who consider, and advertise themselves as the ‘toughest’ ultra-marathon in the world, yet they are all so varied that it’s impossible to label such races with such a prestigious title. Such events may be considered the ‘longest’, ‘highest’, ‘hottest’, ‘coldest’, ultra-marathons in the world, or even the ‘one with the most elevation gain’ could be considered the toughest…you decide!

Yet, three things to consider when competing in any such event are:

  1. You will need to consume some kind of fuel during them
  2. You will need to train specifically for them
  • They always seem to be damn beautiful no matter where you are in the world

In this article, similar to ‘The Lakeland 100’ issue, we will take a look at fuelling yourself through a typical ultra-marathon. This ‘typical’ ultra-marathon is with regards to something like a 100-mile distance and/or maybe 24-30 hours’ time spent on the race course, and does not take in to consideration each events’ ‘potential difficulties’ or ‘hostile environments’.

Generally, ultra-marathons are continuous in nature; therefore, competitors have the choice whether to stop and rest for a while, or even sleep on the route, however, with all events having some kind of time-limit, and cut-off points for check-points, time is not on your side. With several manned, and/or unmanned checkpoints along the routes, there are plenty of chances to refuel and rehydrate to aid in your completion of such an extreme event. However, such demanding events do require a certain experience in ultra-distance running, including full/semi-autonomous support in hostile environments, confident navigational skills, and an ultra marathon training plan.

Yet, contrary to popular belief, it is not typically poor map reading skills, or technical terrain per se, which ends many of the competitor’s race, neither is it hostile weather, or even the negative over-riding psychological doubts which can creep in during the night which cause many athletes to call it a day and DNF from the race! It is more often than not, poor refuelling and rehydrating which leads to a potential race-ending issue!

A solid training plan is essential for ultra-marathon running, however nutrition is paramount (1), with 90% of ultra-marathon runners agreeing that nutrition has an important influence on overall performance (2), and with an understanding that adequate food and fluid is related to a successful ultra-endurance finish (3). A poor refuelling and rehydrating strategy for such extreme and demanding events as ultra-marathons can cause many physiologic and psychologic issues over such a prolonged period, and will most definitely hinder performance to some degree:

  • Dehydration
  • Hyponatremia (water intoxication due to the intake of too much water)
  • Muscular tightness
  • Lack of concentration (navigational errors)
  • Low glycogen levels (little to no energy)
  • Poor performance due to fatigue
  • Gastrointestinal issues (stomach cramps, diarrhoea, sickness)
  • Irregular thermogenesis (trouble keeping the body cool or warm)
  • Suppression of appetite caused by over-exertion
  • Flavour fatigue which may lead to less calories going in
  • Feelings of negativity
  • Injury
  • DNF (end of the road…!)


If we consider, for just a moment, the crème de la crème of ultra-endurance athletes, those individuals who really are at the top of their game; the Brownlee brothers (World champion triathletes), Chris Froome (3 x winner of Le Tour de France), François D’Haene (2 x winner of UTMB), Rory Bosio also (2 x winner of UTMB), Lahcen Ahansal (10 x winner of MDS), to name just a few. The training regimes of these athletes are not for the mere mortal, and neither are those of their competing counterparts who take part in some of the world’s most extreme and demanding events…so what is it that seals the win for such notoriously hard-working athletes when they all seem to train to a similar standard?

Nutrition & hydration is the key! Finding a refuelling & rehydrating strategy which works for them may be the difference between performing and failing, between fighting and fatiguing, between winning and losing!

However, most of us are not super human, and are most definitely not part of the crème de la crème club of endurance athletes, yet nevertheless, even if you think you train like a champion, and believe physically, that you are ready to take on an event such as the Western States 100 Mile Endurance Run, training is secondary to nutrition, as nutrition is the key to success.

I promise you this, get your refuelling and rehydration strategy wrong…It’s pretty much game over for the elite, let alone for us mere mortals!

Hands up if you drive around in your car just to empty its petrol tank so that you can just fill it back up again! Nobody?

Everybody puts petrol in their car so that they may drive around in it, Right!  

|Then let us start treating our body’s as we do our cars, fuel them for performance, don’t utilize them just so you can refuel them!

Here at Mountain Fuel® we do not suggest that we are the ‘be all, and end all’ of your nutrition problems, neither do we promise to make you fly. However, our products are designed to be used alongside a ‘food first’ approach to training, and as part of a confident, well-organised refuelling and rehydrating strategy throughout the course of such demanding events as ‘Ultra Trail de Mont Blanc’, ‘Transvulcania’, or even my own personal dream race ‘The Yukon Artic Ultra’. Due to the nature of our products they can also be used in conjunction with other energy bars /snacks and if needed gels, although we encourage our users to negate or limit the intake of gels as a fuel due to their potential to increase the risk of gastrointestinal problems.

Attempting to write a nutrition article specific to one event, and individual to each competitor is near impossible, in fact I’ll go as far as saying it is definitely impossible!! (Mountain Fuel® are currently working on creating individual periodized nutrition plans and athlete support documents for future clients, so please keep a look out for new developments!). Consequently, the following advice is just that, a guideline on how to fuel yourself through a typical 100-mile, or so ultra-marathon.

Nutrition Pre-Event:

Building up to such an event it is vital for competitors to stay fit and healthy. Making it through a heavy training regime, and especially through a taper period is key to making it on to the start line. Prolonged periods of training can put huge stresses on the body, and also weaken the immune system causing physical barriers to infection to become more porous (4), hence the importance of eating a well-balanced diet in the weeks and months before your event. We don’t encourage, or advice drastically changing your diet without seeking professional medical advice, and/or too close to your event.

The rigmarole of several days of carbohydrate-loading seems to be a thing of the past among current athletes now due to the typical daily replenishments of glycogen stores through a higher carbohydrate diet (5), and consequently, muscle and liver glycogen stores are potentially able to be fully replenished within a 24-hour period before an event (6).

With this in mind, and also the potential start times of some events being very unsociable, competitors should aim to consume a high-carbohydrate meal (200-300g/CHO) at least 24-hours before the start of the event to help replenish glycogen stores. It would also be recommended to consume a medium-carbohydrate:protein snack such as Mountain Fuel® Night Fuel 30-40-mins before bedtime to aid in the body’s replenishment of essential nutrients including carbohydrates and proteins.

Due to numerous reasons, sleep is generally deprived the night before an event and competitors are typically awake and up preparing food, travel, and last-minute kit checks…and potentially unable to ingest a decent breakfast. This is considerably common on the morning of a race, so relax and just consume a snack of maybe some fresh fruit, or sip a bottle of Mountain Fuel® Xtreme Energy Fuel, until later on in the morning when you are ready and able to consume a more substantial breakfast containing complex carbohydrates and proteins. For example, Mountain Fuel® Morning Fuel with a blend of oats, mixed seeds and maple syrup is a great start to any ultra-marathon race day (see Table 1).

Due to the late start of some events, it is recommended in these cases to consume a medium-GI carbohydrate meal around 3-4-hours before the event is due to start to optimize glycogen stores.
If you are able to consume an early breakfast (6-7am), and then eat lunch around midday, this would enable the consumption of a Mountain Fuel® Morning Fuel as an alternative light meal of porridge around 3-4 hours before the start of the event, if you feel a larger meal (see Table 1) would be too much for you.

Throughout the morning it is advisable to stay well hydrated too, via the consumption of plain water.

During the final hour building up to the race start it is recommended to begin slowly consuming Mountain Fuel® Xtreme Energy Fuel to ingest those final vital calories of carbohydrate ready for the event ahead.


Table 1: Nutritional Example-24 Hour Build-Up:

Pre-Race (Hrs) Food(s) Portion Serving Total Nutrient Content
24 Baked Sweet Potato

Mixed Lentils in Sweet Chilli Sauce

Raw Spinach

Seeded Bread





2 slices

225g Carbohydrate

35g Protein

9g Fat


21 Mountain Fuel Night Fuel


50g 25g Carbohydrate

5.4g Protein

0.3g Fat


12 Mountain Fuel Xtreme Energy + Banana 50g

1 large

65g Carbohydrate

6.5g Protein

0.2g Fat


8 Mountain Fuel® Morning Fuel (50g) with oats (40g), seeds (15g) & coconut oil (1tsp)


Poached Eggs

Seeded Toast

Espresso Coffee






2 slices

1 shot

68g Carbohydrate

16g Protein

16g Fat


24g Carbohydrate

21.5g Protein

15g Fat


4 Mountain Fuel® Morning Fuel (50g) with oats (40g), seeds (15g) & coconut oil (1tsp)



Baked Salmon Steak

New Potato & Couscous Salad

Wholemeal Pitta Bread

Double Espresso

Cantaloupe Melon







1 steak




1 medium slice

68g Carbohydrate

16g Protein

16g Fat



59g Carbohydrate

56g Protein

41g Fat


1 Mountain Fuel Xtreme Energy 50g


40g Carbohydrate

5g Protein

0.1g Fat



Nutrition During the Event:
So, after weeks and months of training hard, sleeping well, and eating a nutritious, well-balanced diet to help stay fit & healthy, race day has finally arrived…the final countdown is closing in…and your nutrition & hydration plans are in place…or are they?

It is well documented throughout research that endurance athletes can, and potentially should aim for consuming ~60g/CHO/hr as this is the optimal amount which can be oxidized by the body (7), however, a 2006 study found that there was a positive link to mixing the types of multiple transportable carbohydrates, such as fructose, glucose, and maltodextrins and an increased oxidation rate (up to ~90g/CHO/hr) which may lead to a delay in fatigue during exercise performance (8), yet this does involve some training of the gut to be able to take on board such high amounts of carbohydrates during physically activity, so please do not attempt this on your race day. Even with training, GI-stress can still occur, especially when taking part in such prolonged events as an ultra-marathon.!!

The mixture of multiple transportable carbohydrates has also been shown to be easier on the gut and decreasing the risk of any gastrointestinal issues.

This is definitely the impossible bit; to suggest a nutrition & hydration plan for a generic type of ultra-endurance runner just cannot be formulated unfortunately, as we all know, nutrition is very personal to the individual, and potential issues which are out of your control ie weather, temperature, distance between check points etc, make this task even more impossible. However, there are general recommendations, and guidelines for such endurance events:

Aiming for 60g/CHO/hr maybe too much for many people, and possibly too little for others, and this is where the flexibility of Mountain Fuel® products step in. Carrying two hydration bottles is key for a good hydration strategy and we suggest you have one filled with plain water, and the other with Mountain Fuel® Xtreme Energy Fuel to a mixed concentration of your own personal choice, so that each individual can control their own consumption, of both water and carbohydrates. This part of a strategy plan should be carried out throughout the race via topping up bottles at each aid station and sipping both bottle contents between each. This liquid fuel should also be interspersed with real solid food snacks (energy bars, flapjacks, energy rice balls etc), for as long as your stomach can process the solid contents. If you reach a stage in the event where you are unable to continue eating solid foods then attempt to increase the amount of liquid fuel which you are consuming, and, if the worst comes to the worst, and you can no longer stomach anything, it is vital that you continue to keep sipping plain water until you are able to begin metabolising and utilizing fuels again.

Many of our athletes have successfully used Mountain Fuel ® Ultimate Recovery and/or Morning Fuel during endurance events. These products are very lightweight, easily carried, and/or utilised from in-race drop-bags. Then mixed with water or soya milk they make a great alternative fuel source to compliment energy intake.

There will be times in events such as ultra-marathons where you become confused, and are unaware that you are not eating and/or drinking the correct amounts…this is where having good experienced and reliable check point staff and crew members are essential to finishing success, and we will be producing an article on the importance of staff & crew teams so please keep an eye out for that one.

You may be also aware of ‘flavour fatigue’ too. This is where you become so accustomed to eating the same types and/or flavours of foods for hours and hours that your body just won’t tolerate them anymore. This may then lead to a decrease in calories going in, and ultimately energy coming out, and again points to having a solid plan including various types, textures and flavours of foods available to you. This topic is beyond the scope of this article but will be discussed in a future episode so again, please watch out for that one.


Nutrition Post-Event:

A solid, well-organised recovery plan, is an integral part of decreased recovery time & increased recovery ability, especially after such demanding and exhaustive events.

It is suggested that carbohydrate intake is increased to help glucose stores be restored (see Pre-race recommendations). Protein consumption should also be increased to ~1.5-2g/ to aid in whole body recovery and muscle rebuilding. Pay attention to amino acid intake especially leucine, as this is a key amino acid for muscle protein turnover regulation (see ‘Understanding Protein’ for lists of amino acids). All of the recommended nutrient intake increases should be done through a food first approach and yet through the addition of supplements when and where needed.

Here at Mountain Fuel® we really do like to boast about how wonderful our Mountain Fuel® Ultimate Recovery Fuel drinks are, with over 11g of blended whey and soy protein, all 11 essential amino acids, and flavours which are second to none, we recommend consuming one of our recovery drinks after such an event too allow the recovery process to begin. This can also be continued on a daily basis to continue the recovery basis and to increase the time of recovery through muscle protein turnover.

“I competitively race a lot, so far this year I’ve completed The Spine (5th), Hardmoors 200 (2nd), London Marathon (3hr 1min), 3 Peaks fell race (4hr 8min), the final leg of the Dragons Back and numerous Bob Graham support legs and I’m able to fuel on the go and recover using Mountain Fuel’s Chocolate Recovery, there’s simply nothing tastier and more effective.” Paul Nelson (50yrs)

Key Points:

  • Remember!, nutrition is very personal to the individual so do not take a generic strategy and think that it will work for you.
  • Try and stay off of your feet for as long as possible in the 24-hour build-up phase to the event.
  • Hydrating is more important than refuelling with regards to positive forward motion ie: if you can no longer eat then continue to drink. You will slow down; however, you may still be able to finish. If you stop drinking too it is generally game over!
  • Do not rely on check points for your nutrition, yes use them, but always have a backup plan in case you get lost, or cannot eat the foods which they provide.
  • Have your snacks at hand so that there is no need to rummage through backpacks for your fuel, and keep snacks lightweight if possible. Remember, for some events you have to carry everything from the start (apart from any potential drop bags allowed) so don’t go packing mountains of food for your lunch!
  • Keep refuelling and rehydrating, little & often, rather than large amounts less often.
  • Try and keep energy gels if you really need them for the latter stages of the event so as not to increase potential GI distress.
  • Make mental notes of urine colour and frequency to keep hydration optimized.
  • Finally, remember that so many other potential factors (weather, temperature, sickness, dropping & losing snacks, flavour fatigue, dehydration, exhaustion, missing check points etc.) may alter your primary nutrition & hydration strategy so have more than one, in fact have various plans, foods, snacks, drinks, and ‘what if this happens’ backup plans.







1– Williamson, E. Nutritional Implications for Ultra-Endurance Walking and Running Events. Extreme Physiology & Medicine. 5:13 (2016)

2 Kruseman, M; Bucher, S; Bovard, M; Kayser, B and Bovier, P.A. Nutrient Intake and Performance during a Mountain Marathon: An Observational Study. Eur. J. Appl. Psychol. 94:151-157, (2005)

3Stuempfle, K.J; Hoffman, M.D; Weschler, L.B; Rogers, I.R and Hew-Butler, T. Race Diet of Finishers and Non-Finishers in a 100-Mile Mountain Foot-Race. J. Am. Coll. Nutr. 30:529-535, (2011)

4– Currell, K. (2016) Performance Nutrition. Wiltshire, UK, Crowood

5– Haff, G.G. (2013). Essentials of Sports Nutrition and Supplements: Carbohydrates. NJ, USA, Humana Press

6 Tardie, G. Glycogen Replenishment After Exhaustive Exercise., (2008)

7– Kreider, R.B; Wilborn, C.D; Taylor, L; Campbell, B; Almada, A.L; Collins, R; Cooke, M; Earnest, C.P; Greenwood, M; Kalman, D.S; Kerksick1, C.M; Kleiner, S.M; Leutholtz, B; Lopez, H; Lowery, L.M; Mendel, R; Smith, A; Spano, M; Wildman, R; Willoughby, D.S; Ziegenfuss, T.N and Antonio, J. ISSN Exercise & Sport Nutrition Review: Research & Recommendations. Journal of the International Society of Sports Nutrition. 7:7 (2010)

8-Jeukendrup, A. E. Carbohydrate Intake during Exercise and Performance. Nutrition. 20 (7), 669-677 (2004)