What To Eat The Day Before And Morning Of An Endurance Race?

Okay, no lies here, have you ever done this? The day before a race you head to a pro panel or watch their latest YouTube. Hear that your favourite professional athlete has oats and honey (or whatever the new hype food is) on race morning, so the next morning you do this too. Even though you’ve never had this before training or racing. Can you relate?

The number of my clients who have reported doing this even when we had a full race week plan prepared is worrying. It might be fine and all goes well, or you might have gut issues all day. I’m not sure about you, but I don't want to roll that dice. Hence the urge to write this article to ensure you all ‘don’t try something new on race day’. Or race eve for that matter. For the context of the next few recommendations we are talking about any endurance event that lasts over 1 hour (i.e. Olympic distance triathlon, half distance IM or triathlon, full distance IM or triathlon, half marathon, marathon, HYROX, XTERRA). Okay, let’s dive into the key components of nutrition for T-24 hours.

Carbohydrates and calories

On a daily basis both males and females should be eating a baseline calorie intake of 45-60 calories per kilogram of fat-free mass (1). During the days leading into a race we tend to be training less therefore, although you may think we need to drastically increase our intake, we actually don’t. This is because the energy usually used during training is now being stored in our muscles as glycogen or triglycerides. Our storage capacity is different between genders. Two consecutive studies have shown that men may be able to increase their muscle glycogen concentration by 23-41% while women may not be able to increase their storage at all, best case a potential increase of 17% (2,3).

This means that women should not go crazy on the carbs leading into a race and take a more balanced macronutrient approach while men can be more carb focused. For example the night before a race males might want to opt for a large supreme pizza (400 Cal. 71g Pro. 46g Fat. 158g Carbs), while females might go for 1.5 cups of rice, 120g of chicken and ½ an avocado (600 Cal. 40g Pro. 12g Fat. 76g Carbs).

Reduce fibrous foods

Fibre is essential for good gut health, helping to eliminate cholesterol from the body, assisting with satiety, metabolic processes and reducing inflammation (4). However fibre is an indigestible carbohydrate and therefore brings fibrous matter into the digestive tract. It is most commonly found in fruit, vegetables, grains, nuts and seeds (4).

Fibre can cause an issue on race day where blood flow is redirected from the digestive system to the working muscles. The lack of blood flow to the gut mixed with high gut residue is what can cause runners' gut, unwanted toilet stops and a feeling of heaviness on race day.

Usually on a day to day basis it is recommended we consume 20-25g of fibre per day (4). During race week I aim to get my athletes consuming less than 10g per day.

Snacks that are low in fibre but high in carbohydrates are;

Keep in mind that low fibre foods are not necessarily healthy or recommended as everyday foods but should be chosen leading into a race to assist with performance and reduce potential issues that may arise during endurance races.

Hydration

The night before and the morning of a race be sure to have a water bottle on hand that has some electrolytes in it. Plain water isn’t actually hydrating. We need a combination of sodium and water to hydrate the body (5). This can be easily made by adding an electrolyte tablet or sachet to your water bottle such as; Hammer Nutrition - Endurolytes Fizz, Science In Sport (SIS) - Go Hydro Tablets, Koda Nutrition - Electrolyte Powder, Hyro - Electrolyte Hydration Mix or Huma Gel - Hydration Drink Mix.

Familiarity

It sounds so simple to consume foods/ meals we have had before but often athletes are so mentally exhausted getting ready for a race their thought for race night or race morning food is not considered. Try and write down a few weeks before what you are going to have the night before a race. If it's take-out then do your research around the local area or see a dietitian to individually tailor a race week meal plan for you.

Ideas for race morning

On race morning you want to have your main meal 2-3 hours before race start to boost blood sugar levels but allow time for digestion. Remember this should be low in fibre, have some simple carbohydrates and protein. This could look like; A bagel with cottage cheese and maple syrup, oats and yoghurt, banana and peanut butter or Radix Nutrition - Low FODMAP Breakfast - Chocolate.

20 minutes before race start take on your pre-race carbohydrates. This is usually a gel, chews or a bar. It takes 20 minutes for a food to be absorbed into the bloodstream and therefore if timed right you should get a boost in blood glucose levels right at the start time.

More on race week nutrition

Please consider for long endurance events we should be considering the above nutritional recommendations for the whole week before a race.

Read more about race week nutrition here.

Race week nutrition plans here.

Ash Miller
Dietitian and Nutritionist (Masters)
Bachelor of Physical and Health Education
Instagram: @ashthomo_nutrition

^References^:

^{Morehen JC, Rosimus C, Cavanagh BP, Hambly C, Speakman JR, Elliott-Sale KJ, Hannon MP, Morton JP. Energy Expenditure of Female International Standard Soccer Players: A Doubly Labeled Water Investigation. Med Sci Sports Exerc. 2022 May 1;54(5):769-779. doi:}

^{Tarnopolsky MA, Zawada C, Richmond LB, Carter S, Shearer J, Graham T, Phillips SM. Gender differences in carbohydrate loading are related to energy intake. J Appl Physiol (1985). 2001 Jul;91(1):225-30. doi: 10.1152/jappl.2001.91.1.225. PMID: 11408434.}

^{Tarnopolsky MA, Atkinson SA, Phillips SM, MacDougall JD. Carbohydrate loading and metabolism during exercise in men and women. J Appl Physiol (1985). 1995 Apr;78(4):1360-8. doi: 10.1152/jappl.1995.78.4.1360. PMID: 7615443.}

^{Barber TM, Kabisch S, Pfeiffer AFH, Weickert MO. The Health Benefits of Dietary Fibre. Nutrients. 2020 Oct 21;12(10):3209. doi: 10.3390/nu12103209. PMID: 33096647; PMCID: PMC7589116.}

^{Biswas M, Davies JS. Hyponatraemia in clinical practice. Postgrad Med J. 2007 Jun;83(980):373-8. doi: 10.1136/pgmj.2006.056515. PMID: 17551067; PMCID:PMC2600061.}