RACE PREPARATION NUTRITION – Guidelines for Ultra Distance Events

So here you are, just a week away from your key race, wondering what else you can possibly do to get an extra 2% out of yourself on the big day. Refining your nutrition pre-event may give you the boost you’re seeking if you’re a first timer, or you still don’t have a tried and tested nutrition strategy in place for race week. Here I’ve put together a summary of simple principles that may help you to better achieve your event day goals with more energy and less chance of a grumpy gut.

Whether you’re on a high fat – low carb diet, you’re vegan or paleo, a flexitarian or just simply confused about what to eat pre-race, carbohydrates are your friend on the day. Carbohydrates are turned into glycogen, the preferred source of fuel for your working muscles and brain. Although your body will also have adapted to burning body fat for fuel during all those long-distance training sessions, starting the event with well-stocked glycogen reserves is the smartest approach to limit the fatigue which can arise with glycogen-depletion.

The old carbohydrate loading protocols required a glycogen depletion diet and high exercise phase of several days which was then followed by carbohydrate loading while doing minimal activity. In practice this type of diet and exercise manipulation could be stressful for an athlete right before important events. More recent studies have indicated that muscles can super load glycogen in just one day of inactivity to the same effect as three days of carb loading intervention. Also, glycogen loaded muscles can maintain elevated levels for several days, even if carbohydrate ingestion reduces.

By the time you enter race week, you should be tapering with a substantially reduced training volume and intensity. If you don’t modify the way you eat, then the reduction in energy expenditure will naturally lead to some carbohydrate storage. However, most us don’t stop training completely – so in order maximise carbohydrate storage for the day, it makes sense to add extra carbohydrates.

For distance events such as a marathon or longer the super-loading glycogen recommendations are 10 – 12gm carbohydrate per kilogram body weight, per day. For best results, choose a day one to three days out from competition where you will be doing the least amount of activity and load on that day.

How does this work in real life?

If you’re one of those people with a cast-iron gut who can eat a lot of anything without any problems, then you can continue to eat normally and super-load carbohydrate in the last 36-24 hours. This is a time when you can freely add high glycemic index foods, as they are quickly digested and absorbed.

However, many people (myself included) suffer from gastric distress in the days leading up to an event. Quite often this is caused by pre-race nerves and the stress of travel or last-minute dramas – nausea, loss of appetite, constipation or diarrhoea are common. This can make eating more food seem impossible.

It’s important to note that you will put on a little weight when super-loading, maybe an extra 1-2kg, however some of this is water weight, and you’ll lose all this and more during the race itself.

If you’re a first timer, or you tend to experience a grumpy gut in your race leadup, then consider following some, or all, of these suggestions:

1. Carbohydrate load over 2 – 3 days

Trying to super-load in 24 hours means eating a lot of food during that single day and this can easily result in bloating, indigestion, lethargy etc. If you add extra carbs in smaller amounts over two or three days pre-event, this reduces the digestive load, while still allowing your muscles to increase their overall glycogen stores. For most people, medium and high glycemic index (GI) foods are the best for super-loading.

High GI = white rice, white bread, GF white bread, rice crackers, dry spaghetti (cooked 20 mins), sports drink, sports gel/chew, dates, watermelon, pumpkin, potato, scones, pancakes, cakes and biscuits, corn chips

Medium GI = sports bars, muffins, most whole-grain based breakfast cereals, couscous, polenta, grain crackers, grainy breads, kumara, banana, canned fruits in syrup, dried fruit, corn, potato chips & grain-based snacks

Low GI = fresh pasta (cooked 5 min al dente), porridge, legumes, whole grain breads, whole grains & cereals, most vegetables and fruits

2. Go low fibre

Reduce the fibre content of your meals. This is often a cause of race day gut discomfort/distress – whether it’s an anxious wait in the porta-a-loo line on race morning or having the runs on the run.

3. Avoid FODMAPS

If you have a sensitive stomach or bowel in the lead-up to races, I suggest that you familiarise yourself with FODMAP, which is a form of food intolerance. A short term FODMAP avoidance diet can reduce gastric issues on race day for some people. For example, oligosaccharides are very fibrous and can cause bloating and gas (eg. onions and chickpeas), high fructose fruits can cause gut distress (eg. apples and peaches). Consider avoiding all FODMAP aggravators that you know give you upper or lower gut problems. There are many good resources online for this.

4. Stick to the familiar

Eat foods and meals that are simple and familiar – this isn’t a time to get adventurous eating out when visiting new places. Save those mouth explosions for after the event.

Foods to minimise/avoid (depending on individual gut tolerance levels):

  • Whole grains and cereals, and pseudo cereals (eg. quinoa, buckwheat)
  • Fresh fruit with skin, pith and pips/seeds
  • Dried fruit
  • Legumes – all beans, hummus, falafel etc
  • Nuts and seeds
  • Most raw vegetables (especially mushrooms, cruciferous and root vegetables – carrots, beetroot, broccoli, cauliflower etc)
  • Fermented/pickled vegetables
  • Deep fried and fatty foods
  • High fat dairy foods
  • Highly spiced or salted foods – avoid excess

Foods to eat more of:

  • White bread, plain baking (eg. plain scones, pancakes)
  • Pasta & white rice
  • Tofu
  • Eggs
  • Lean animal proteins – chicken, fish, meat
  • Cooked vegetables – potato, kumara, pumpkin
  • Pureed vegetable-based soups
  • Canned/stewed fruit, peeled and deseeded – tropical fruits (fresh)
  • Fresh fruit/vegetable juices without pulp
  • Smooth nut butters
  • Avocado for healthy fat
  • Add a little extra salt (to top up stores for race day)

An example – my plan:

Nutritional research studies are usually carried out in artificial test environments and mostly on male athletes – so whatever the nutritional science says, you will only know what works best for you through testing how your own body responds in training and racing, especially if you’re female.

In the past 15 months I’ve completed 6 ultra-events (1 full Ironman, 4 half Ironmans and 1 marathon) as well as several 5 hour plus event simulation days. Next week I’ll be doing my second full Ironman.

I have irritable bowel, food allergies and intolerances and I’m plant-based so getting the nutrition right is very important for me. I’ve experimented with one day super-loading, 2-3 day carb loading, and not loading at all. I get a better result when I carb load, however single day super loading leaves me feeling too heavy and uncomfortable, so I prefer to load over the last 2 days pre-event while my activity level is low. I go lower in fibre and higher in GI in the last 2 days, and rely on drinks for extra carbohydrates as I find it difficult to successively eat large quantities of food.


My weight = 54kg

Carb loading over 2 days @ 10gm carb and 1.6gm protein per kg bodyweight

Meal / snackCarbohydrate
= 540gm
Protein = 86gmSample food choices
Breakfast120gm20-25gm1. Fruit, paleo granola, coconut yogurt, muffin, soy latte
2. Pancakes, berries, syrup, almond yogurt, soy latte
Snack60 gm0-5gmSmoothie/sports drink
Lunch120gm20-25gm1. Large scone & jam, mixed salad, tofu, juice
2. Avocado smash of 3x toast, 2 eggs, sweet treat, soft drink
Snack60gm5-10gmSmoothie/sports drink
Dinner120gm20-25gm1. Vegan burger, roast vegetables, soft drink
2. Pasta, grilled vegetables, nuts, soft drink
Snack60gm0-5gm1. Vegan ice cream
2. Vegan custard + tinned fruit

Nutrition Tips for Race Day

On race morning your goal is to top up your glycogen stores in your liver and muscles as these drop overnight. The recommendation is to have a breakfast containing 1 – 4gm carbohydrate per kg bodyweight. What you eat, how much you eat, and when you eat, should be adjusted for your personal gut tolerance. The general rule is to eat 2 – 4 hours before your start time, and less solid food closer to the event, as it may not be digested before your race start. Choose carbohydrate foods that will be easily digested – these tend to be low fibre, low fat and low protein. Liquid meals options may be a good choice if you suffer from pre-race nerves and struggle to eat, as liquids are absorbed and emptied more quickly. If you’re a first timer you should have trialled your pre-event breakfast in training at least once to be sure that you will be comfortable on race day morning.

Sample race day breakfasts include:

  • Eggs, toast and juice
  • Bagel with peanut butter and a banana
  • Cereal, yogurt and tinned fruit
  • Porridge with milk and honey.

The other key factor on race morning is to ensure that you start the event well hydrated, especially in hot conditions, as this will help you to maintain optimal hydration for longer during the event – a small degree of dehydration is normal in ultra distance races. This means drinking at least 500ml with your breakfast, and then sipping another 200-300ml up to start time. Don’t worry about getting caught out for a last minute pee – you won’t be the only one doing it in your wetsuit. I won’t discuss race day hydration in detail as that’s a separate topic for another day.

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