Marathon Nutrition Guide


With the longest day of the year past, and those classic Spring marathons behind us, I guess we can now begin to think on switching our training to those lovely Autumn races, the nights slowly pulling us back in, and the horrific thought of “did I clean my fell-shoes after last year’s final winter bog-fest race?” as you prepare to delve through your ‘running-shoe-cupboard’ to dust off the winter steads!

Training plans will be being rewritten, scribbled on, and crossed out. Threshold sessions being frowned at, races being planned, and new head torches being purchased. Reccie runs will be organised, maps bought, and new waterproof’s put through their summer hosepipe tests (or is that just me?!).

All of this training, preparing, and organising, and yet so many individuals rarely consider, and even overlook the most important question with regards to completing such a distance, whether competitive or non-competitive; How am I going to fuel this performance? Thus, indicating the underappreciation of the vital role which nutrition & hydration have in marathon running (1).

In my honest opinion, and through my many years of performance experience in both running and cycling, those 26.2 miles of a marathon (trail, fell, or road) are definitely one of the most difficult distances to get right with regards to nutrition & hydration strategies; “There’s no place to hide, no time to cry, no second chance if the final match has gone out; stripped bare, stripped raw with nothing more to give!”

Hands up if you’ve hit that same wall…yup, its bloody well soul destroying and a tough slog home!!

However, marathon running does not need to be like this; a throw of the dice to whether you can finish the distance before you suddenly face-plant in to that ‘dreaded wall’ or not.

What Makes a Marathon Nutrition Strategy So Tricky?

Distance: the 26.2 miles of a marathon is slightly too long of a distance to be able to complete without taking onboard some kind of fuel, even for the top elite runners in the world. We, as humans are able to store enough glycogen (energy) in our body to fuel ~2-4 hours of moderate intensity exercise (2,3) during which, performance will decrease if glycogen levels are not replenished throughout the duration.

Race Duration: even those elite athletes who are currently trying to break the 2-hour marathon cannot risk overlooking the importance of replenishing carbohydrate stores whilst on the run, so why should us mere-mortals think that we can run, walk and/or stumble our way through 26.2 miles without giving any consideration to what we are eating pre-and during the event. The time in which you will spend completing the distance will play a major factor in your nutrition & hydration strategy. If you are aiming to complete the race in 3-hours or less then build your nutrition & hydration plan accordingly. Likewise, if you are a more leisurely paced runner who is aiming for 5-6-hours or even longer, then again, plan your fuel & fluids for this duration.

  • Intensity: how hard you run, or higher intensity races, are going to be one of the key variables to how you prepare for the event with regards to nutrition & hydration. The intensity of a race, could indicate variables including: running speed, mountainous terrain, hot weather, fitness levels, individual body-mass. These variables can all make one individuals race more or less intense than another individual, and therefore can totally change personal nutrition & hydration strategies. The more intense your race, the more energy you will need to keep up that intensity.
  • Pre-race Fuelling Strategy: this is probably the one area in which people pay the littlest attention to, and yet is arguably one of the most, if not thee most important area to concentrate on when building up to marathon running. Starting an event such as a marathon with high levels of glycogen stores is essential to optimizing performance over those first few miles without your body running out of energy far too soon.
  • Miscellaneous: if trying to build a well structure nutrition & hydration plan in to your marathon race isn’t difficult enough; along come those nasty, sometimes unable to control variables which just rip up your perfectly organised plan and makes you think why bother! Weather, limited foods and/or fluids at check-points, no real second chance to replenish energy stores, or an in-race injury will all effect the greatest of fuel & fluid plans which is why you should always have more than one plan- THINK; what will I do if this particular incident happens during my race?    

How Do I Stop Marathon Nutrition Being So Tricky?

Well firstly, remember you need to begin thinking about fuelling, and increasing glycogen stores way before the morning of your race/event. This no longer needs to be through the horrible old-school regime of ‘carb-loading’ (4) in the days building up to your race, but can easily be achieved through a general, sustainable well-balanced diet, with an increase of carbohydrate consumption over the 24-48 hours pre-race period. This increase should equate to ~70-75%/CHO/total daily kcals (5), however, should be introduced in to training phases before competitive events to allow the body to become comfortable with larger amounts of carbohydrates if your body is not used to higher carbohydrate consumptions (DO NOT try this 24-hours before your first marathon, as you will increase the possibility of GI distress and other adverse effects). These increases in carbohydrates can easily be undertaken by increasing foods such as rice, potatoes, pasta, fresh fruit, and carbohydrate loaded drinks such as Mountain Fuel® Xtreme Energy Fuel drink which can be sipped throughout the days building up to the event, and on the morning of the event to help top up crucial glycogen levels pre-race. Mountain Fuel® Morning Fuel may also be used as a pre-race breakfast alternative, and is delicious with bananas and a little maple syrup.

I guess, no matter where you are in your ‘race bubble’ whether it be pre-race training, pre-race tapering phase, mid-race, or recovering post-race, nutrition & hydration strategies are always about planning, organisation, and being prepared for the unexpected, this is pretty much KEY with regards to marathon fuelling not being tricky!!

If you have already read through some of our other Mountain Fuel articles such as ‘Macronutrients’, ‘Understanding Carbohydrates’ or ‘The Lakeland 100’ then you will be aware that current guidelines for in-race carbohydrate consumption states that individuals can only generally oxidize 1-1.1g/CHO/min (~60g/hr), with a possible increase up to ~90/g/hr in well-trained athletes (6). Here at Mountain Fuel® we suggest that this be done by consuming our Mountain Fuel® Xtreme Energy Fuel throughout the event. Mixed with 500ml of water, 50g of Mountain Fuel® Xtreme Energy Fuel will provide 40g of energy providing carbohydrates, which may be increased to 60g with an extra scoop popped in to your water bottle. Mountain Fuel® Xtreme Energy Fuel provides a gentler sustained energy release, and is much easier on the stomach than energy gels are, however, that’s not to say that energy gels are an absolute no, for some athletes who are pushing really hard in-race need a much quicker energy release and therefore energy gels do have a place in sporting performance, but should be used with caution and experience.

As stated earlier, your nutrition plan should be very bespoke to you and your race goals (3-hr Vs 6hr = very different fuelling strategies). An individual who may take 5-6 hours to complete their race may need to consume some solid foods such as a small piece of flapjack, Morning Fuel® pancakes, or a banana during the event to stop any GI stress from liquid consumption only. Whereas the faster runners may be able to reach their race goals consuming liquid energy alone.

Remember, everybody is different, everybody’s goals are different, so everybody’s marathon nutrition plan should be different!!

And, everybody’s fluid needs are different too. Plain water should be making up a large part of your fluid intake, so DO NOT just consume carbohydrate/electrolyte drinks as this can have adverse effects, as can the consumption of water alone. Suggestions of ~350-490ml/hr (7) of plain water are to be consumed throughout an event such as a marathon, however, just be aware that this range can increase massively depending on many other factors, such as individual body mass, temperature & humidity, and training status.

The importance of getting your pre-race nutritional strategy correct is vital for a successful race, yet it is also essential to aid in post-race recovery and glycogen replenishment (8), after competitive events, but primarily for in-between repetitive training sessions and consecutive phases of heavy endurance training (9). A diet containing ~8g/CHO/ per day is adequate to maintain muscle glycogen stores, but consequently, a diet containing only ~5g/CHO/ per day will not be adequate and will result in significant decrements to muscle glycogen storage (10,11). To aid in pre-race recovery and glycogen replenishment it is advisable to consume both protein, containing the essential amino acids, plus carbohydrates in one form or another, for example, and from personal experience, I have found that 500ml of chocolate/strawberry Mountain Fuel® Recovery drink (sometimes with a cheeky extra scoop in) asap after training/racing helps with muscle recovery, and then over the course of the next 2-4 hours 0.5-2ltrs of Mountain Fuel® Xtreme Energy Fuel helps to quickly and efficiently begin to replenish glycogen and electrolyte levels, ready for the next day’s training or racing.

Key Points:

  • For such distances as a marathon, nutrition & hydration strategies need to be started well in advance of race-day.
  • Increasing carbohydrate consumption to ~70-75% of total daily kcals 24-48 hours building up to the event is generally enough to top up glycogen levels ready for race-day
  • PLANNING & ORGANISATION are key to a well-executed nutrition & hydration plan
  • Practice new nutritional changes during your training, NOT on race day!
  • Glycogen storage and replenishment is vital for both racing, and during heavy bouts of consecutive days of endurance training
  • REMEMBER: Distance, Duration, Intensity, Pre-race nutritional strategy, and those unexpected factors when planning your nutrition & hydration plans
  • Have fun!!



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2– Coyle, E.F; Coggan, A.R and Hemmert, M.K. Muscle Glycogen Utilization during Prolonged Strenuous Exercise When Fed Carbohydrate. J. Appl. Phys. 61. 165-172 (1986)

3– Kerksisck, C; Harvey, T; Stout, J; Campbell, B; Wilborn, C; Kreider, R; Kalman, D; Ziegenfuss, T; Lopez, H; Landis, J; Ivu, J.L and Antonio, J. International Society of Sports Nutrition Position Stand: Nutrient Timing. JISSN. 5:17 (2008)

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

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7– Jeukendrup, A. Nutrition for Endurance Sports: Marathon, Triathlon, and Road Cycling. J. Sports Sci. 1: 91-99 (2011)

8– Economos C.D, Bortz S.S, and Nelson M.E. Nutritional Practices of Elite Athletes. Practical Recommendations. Sports Med. 1616:381-99, (1993)

9– Costill D.L, Bowers R, Branam G, and Sparks K. Muscle Glycogen Utilization During Prolonged Exercise on Successive Days. J Appl Physiol. 3116:834-8, (1971)

10– Sherman W.M and Wimer G.S. Insufficient Dietary Carbohydrate During Training: Does it Impair Athletic Performance? International Journal of Sport Nutrition. 1(1): 28—44, (1991)

11– Pascoe D.D, Costill D.L, Robergs R.A, Davis J.A, Fink W.J, and Pearson D.R. Effects of Exercise Mode on Muscle Glycogen Restorage During Repeated Days of Exercise. Med Sci Sports Exerc. 2215:593-8, (1990)