An ultramarathon. That is a serious challenge!
With such a demanding event and its substantial impact on the body, keeping your nutrition under control is essential for effective recovery.
What is an ultramarathon?
It is difficult to plan your nutrition for an ultramarathon without knowing exactly what it is.
The answer is simpler than running the distance: an ultramarathon is any running race that exceeds 42.195 kilometres, the distance of a traditional marathon.
These events often involve trail running, but road ultramarathons also exist.
Nutrition recommendations for ultramarathons
Which nutrition factors should you consider when preparing?
Train your digestive system
First, train your digestive system to tolerate the hourly carbohydrate intake needed for the race. Supplying adequate fuel supports performance, but you also need to absorb it comfortably.
The body can often absorb around 60 grams of carbohydrate per hour relatively easily; tolerating higher intakes requires practice. The hourly carbohydrate amount depends on the athlete and their needs. Build it progressively to avoid gastrointestinal problems during the event.
Carbohydrates can come as isotonic drinks, semi-solid gels or solid foods such as bars, rice cakes and sandwiches.
Carbohydrate load in the days before the race
The details vary between people, but this is relevant to ultramarathon runners generally.
Start the race with full glycogen stores.
A key energy source is glucose, stored as glycogen in the muscles and liver.
In the preceding days, prioritise carbohydrate intake over fat and protein. It can also help to reduce fibre in the hours before the race to avoid gastrointestinal problems.
Follow your sports nutritionist’s hourly carbohydrate plan
Once you have trained your gut to digest the planned amount, follow the guidance from your sports nutritionist.
More is not always better. The right amount for you is what matters.
Maintain appropriate hydration
The body is mostly water, and exercise causes water loss through sweat. Replacing an appropriate amount helps the body function. Around 2% dehydration can impair performance during an event.
Knowing your sweat rate can help you develop an individual fluid intake plan for the race.
Consider the race-day temperature and humidity, whether your clothing is breathable, the intensity of the event and other conditions.
Consume appropriate amounts of minerals during the race
Pay attention to mineral intake, particularly sodium. Sodium is the main mineral lost in sweat, supports vital functions and plays a key role in intestinal glucose absorption.
An intake of 0.4–0.8 g of sodium per hour may be appropriate, depending on race conditions. Requirements can rise to around 1 g of sodium per hour in very hot weather or for people with high sweat losses.
Vary the flavours and textures of your race food
These races often last well over 3–4 hours. Varying textures, from liquids to semi-solids and solids, and flavours can help prevent monotony.
Alternating sweet products with savoury options such as sandwiches can also help, as sweet flavours may become unappealing over time.
Recover well
After the race, choose a carbohydrate-rich meal with some protein and polyunsaturated fats to support recovery and help manage inflammation.
Recovery should be well rounded: although glucose is a key fuel during the event, some fat and protein are used too. Accompany your meal with water to restore appropriate hydration.
Problems ultramarathon runners may face
These events place major demands on the body, so uncomfortable experiences are not unusual.
Gastrointestinal problems
Athletes can experience digestive problems on race day. Trying a new isotonic drink, gel or bar for the first time can cause intestinal discomfort or an unplanned toilet stop. Race day is not the day to experiment.
Eating more than you have practised during the race can also cause discomfort and heaviness if you cannot digest and absorb the nutrients adequately.
Add race-day nerves, and digestive discomfort becomes even more likely.
Dehydration
Remember to drink water during the event, using thirst and an individualised plan to guide you. Avoid forcing fluids beyond your needs: drinking too much can also be dangerous.
Take race-day temperature and humidity into account.
Hyponatraemia
Hot conditions increase losses of water and salts through sweat. Drinking more fluid than your body needs can dilute blood sodium levels and cause exercise-associated hyponatraemia. Replacing sodium does not prevent this if you continue to overdrink.
This can cause dizziness and fainting, and even death in severe cases.
Muscle cramps and fatigue
The precise causes of muscle cramps are not fully understood. Factors may include dehydration or depleted glycogen stores and low energy availability. To help reduce cramps and delay fatigue, follow your nutritionist’s carbohydrate plan throughout the race.
Follow your fuelling plan even when appetite is low; running out of energy can contribute to cramps and general fatigue.
Your nutrition plan before and after the event should also provide the vitamins and minerals needed for muscle function.
Putting it together
An event like this requires substantial physical and mental preparation. Your training matters: nobody goes from an easy 3-kilometre jog to completing an ultramarathon overnight. Your nutrition and rest need attention too.
Need help with nutrition? Don’t worry: we are here. Explore our subscription options and work with a sports nutritionist who can build a plan around your needs.
