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Marathon nutrition – getting race day right!

Many people forget about the importance of their race day nutrition focusing on their nutrition and training to get them to the start line. However, race day nutrition can be the difference between your clients achieving their target time or simply running a race without stomach upset or hitting the wall so your advice on what to eat and when during the race is critical.  

Assuming that your client has loaded their muscles in the 24-36 hours prior to their start time, the aim of race day nutrition is topping up liver and muscle glycogen stores and hydrating adequately, while ensuring your client is not hungry or overly full at the start line.

As with any nutrition strategy, race day nutrition should be practiced during a training run. This will give your client the opportunity to trial the foods you suggest and they prefer, on their digestion and fine-tune the timings of when they eat and drink to support their race. This should increase their confidence around their race strategy and have a positive physiological impact on their performance.

Although what your client chooses to eat on race day is very individual, there are few fundamental principles they should stick too.
Eating a substantial meal too close the start of the race may result in gastrointestinal discomfort so ensure you get up early enough for breakfast. With the London Marathon start time being around 10am, aim to have your breakfast at around 6-7am. Your breakfast should be focused around carbohydrate rich foods such as porridge oats, cereals, toast bagels and fruits. Again, what you choose exactly is personal preference, eat what works for you. If you are travelling then it could be a good option to prepare your meal the night before and take with you for the journey. Instant oats pots are a convenient option when travelling, and a fruit juice alongside it will help increase your carbohydrate content for the meal. Aim for 0.5g-1g/kg.BW for each hour before the start of the race. So for someone who weighs 80kg then that would equate to 120-240g of carbohydrates. You may also want to include a moderate amount of protein to help with satiety. Natural yoghurt, eggs or a whey protein shake or all good choices. I would recommend that you avoid a large amount of high fat foods with this meal and high fibrous foods as they will take longer to digest, which may cause discomfort during the race.

Here’s a few examples of what that could look like:
•    2 x bagels with jam, 1 x large banana, 1 x small pot natural yoghurt
•    2 x pots instant porridge oats, 1 punnet of blueberries and a whey protein shake
If you struggle with pre-race nerves, and find it hard to digest solid food, a lighter liquid meal could be a good option for you such as my go-to pre-race smoothie:
1 Scoop Whey Protein
50g Porridge Oats
1 medium banana
1 tablespoon honey
300ml water (you can use milk if you prefer)
•    Fill your blender bottle with 300ml water
•    Add the ingredients and give a blitz
•    Add the remaining ingredients and blend until desired consistency is reached

Kcal: 434
Carbohydrates: 63g
Protein: 30g
Fat: 4g
An hour before the race you may want to eat a small carbohydrate rich snack such as a piece of fruit or a cereal bar as a last minute top up.

During the race your body will be burning through your carbohydrate stores so it’s recommended you continue to fuel your body during the race. This can be done through energy gels, energy drinks, foods such as fruit or even a carbohydrate rich energy bar if you prefer. Again this is all personal preference.It is recommended you aim for 30-60g of carbohydrate per hour [1]. An energy gel contains 25g-30g on average so 1-2of these is a good option. Alternatively if you prefer this from a food source, a large banana contains around 30g carbohydrates, as do most energy bars. An energy drink such as a Lucozade also contains around 30g carbohydrate per 500ml so drinking these over the course of an hour is another option.

Do not try anything new on race day and ideally have a test run in the weeks leading up to the race to find out what works for you to help you feel your best when you are at the start line.

Now your pre-race food is taken care of, let’s talk about hydration. Getting your hydration right leading up to the race and during is vital and there is a fine line between being dehydrated and overhydrated when you start the race. The American College of Sports Medicine recommends you drink 5-10ml of water per kg/BW in the 2-4 hours leading up to the race. So for an 80kg runner, this would equate to 400-800ml, with a further 125-250ml in the final hour leading up to the race. A simple way to monitor your hydration status is by checking your urine colour, if it is pale this is a sign you a well hydrated. If it is dark in colour, then you will need to increase your fluid intake.

During the race aim to drink 125-250ml or roughly two or three big swigs every 15-20 minutes. This will depend on the temperature and your own sweat rates. If the temperature soars on race day or you tend to sweat a lot, then I would recommend the upper end of this.

Like with your food, I would suggest you practice your hydration strategy during training to prepare and get a good understanding of how much fluid to take on board to feel at your best. It’s also important to consider your sodium levels, to ensure you replace the salts you lose through sweating. This can be achieved through your energy drink or gel consumed during the race as most of these will contain electrolytes, it’s worth checking beforehand that they do.

With nutrition and hydration taken care of, the final thing to consider is supplementation. Caffeine is one of the most researched ergogenic aids and is regularly used to enhance endurance running performance [2]. Low-moderate dose of caffeine between 1-3mg/kg appears to be sufficient for enhancing endurance performance[3]. Concentrations are in the bloodstream after just 15 minutes and peak 1 hour after ingestion so aim to have you caffeine supplement within the final hour leading up to the race. You can then look to top up towards the end of the race to help power you through the final stages, around 60-90minsis a good time to take this on board, so if your target time is 4 hours, then around the 3 hour mark is fine.

A caffeine supplement containing 150-300mg caffeine is a good dosage and this can be achieved through a drink such as 2-3 serving of Optimum Nutrition Amino Energy, or a double espresso if you would rather have a coffee. If you prefer caffeine tablets then try 4-8 Pro Plus. During the race for you may wish prefer a caffeine enriched energy gel.

These contain between 75mg-150mg caffeine per serving or a piece or two of caffeine gum which contain 100mg of caffeine per piece. Again, this is very individual depending on your caffeine tolerance and body weight so I recommend testing what works in training leading up to the race.

After the race before you go off and celebrate you need to replace the fluid you have lost. Signs of dehydration include severe headaches, muscle cramps and extreme fatigue, none of which are pleasant. Drink at least 500 ml in the first 30 minutes after the race, and then keep sipping every 5 to 10 minutes until you are passing pale coloured urine again.
Consuming 1-1.2g carbohydrate/kg.BW will help you to replenish your depleted glycogen stores [4] and to aid with muscle recovery aim to consume at least 20g of protein. This can easily be achieved through a pint of chocolate milk and a large banana for example.
Take Home Tips

  • Start your day with a carbohydrate rich breakfast to top up your energy stores. Aim for 0.5g-1g/kg.BW for each hour before the race.
  • Caffeine is an effective ergogenic aid which can help cognitive function and energy. An intake of 1-3mg/kg.BW, 15-minutes to hour before the start of the race is optimal.
  • Maintain hydration during the race by replacing lost water and salts through sweating by drinking water and carbohydrate-electrolyte solutions. Drink two-three big gulps every 15-20 minutes, a little more if it’s a hot day or you tend to sweat a lot.
  • Consume carbohydrates in drinks, gels and/or foods if you prefer during the race at a rate of 30-60g/hour.
  • Make sure you test out all of your nutrition strategies extensively leading up to the race so you know what works for you.

Note: This article is supporting content to the Optimum Nutrition for Health and Performance course and is for educational purposes only. It does not reflect the opinion of Glanbia Performance Nutrition, nor is it intended for product marketing purposes.

1.    Jeukendrup, A. et al. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Med, 44, S25–S33.
2.    Graham, T. E. et al. (1991). Performance and metabolic responses to a high caffeine dose during prolonged endurance exercise. Journal of Applied Physiology, 71, 2292-2298.
3.    Goldstein, E. R. et al. (2010). International society of sports nutrition position stand: caffeine and performance. Journal of the International Society of Sports Nutrition, 7, 5-20.
4.    Ivy, J.L. (1998) Glycogen Resynthesis After Exercise: Effect Of Carbohydrate Intake. International Journal Sports Medicine, 142–5.