Skip to content
Close (esc)


Sign up to our newsletter to explore the world of James White Drinks. Expect the latest stories, offers and a healthy dose of pressed juice!



Older Post
Newer Post
Written by James Fleming MSc, SENr

Fuelling the body is a bit like putting fuel in your car. If you add the wrong type of fuel, or worse, no fuel at all, then your performance will be severely affected. A bit like your car, during the run your ‘fuel tank’ will be draining away. We only have limited energy stores within the body (enough for roughly 90 minutes to 2 hours of exercise) so we need to make sure we keep it topped up to help complete the event itself.  

Therefore, the purpose of this article is to provide you with advice around what you should eat and drink during the race itself.  


A high quality, nutritious diet is just 1% of a runner’s development, yet it is the 1% that has an impact on the other 99%. When planned well, nutrition has been shown to have several benefits including:

  1. Maximise performance on race day; helping you to hit your target time or even a PB!
  2. Recover effectively; helping you to reduce muscle soreness and fatigue ready for your next long training run and keeping your legs fresh for race day.
  3. Enhance training adaptation; marathon training places huge demands on the body and nutrition can help to further enhance adaptations – helping you to run faster for longer.
  4. Reduce the risk of injury and illness


Carbohydrate is the main source of fuel for the body during exercise, however we only have limited stores; enough for around 2 hours of high intensity exercise. Therefore, you need to make sure you start your run with your energy stores at optimal levels by fuelling 2 to 3 days before the marathon itself, right up to the morning of the race – this article will focus on fuelling during the 24 hours before race start. You can practice this strategy during your long runs.

RACE DAY -1 (RD-1)

This is 24 hours before your long run or the race itself. The purpose of this day is to load the muscle with fuel ready for the run the next day. This can be done by consuming high carbohydrate meals and snacks throughout the day e.g., breakfast, mid morning snack, lunch, mid afternoon snack, dinner, pre bed snack.

Example of carbohydrate-based foods include rice, pasta, bread, potatoes, cereals, and porridge and carbohydrate-based snacks include cereal bars, fruit (dried as well as fresh) and fruit juices.


As you will start running the London Marathon at any time from 9am to 11am (depending on your expected finish time) I would recommend starting your long runs at a similar time so that you get used to running and eating around that time.

Fuelling for a marathon or long run starts around 3 hours before the start. As the time before the start of the race or run decreases so should the amount of food you consume. Having a high carbohydrate-based meal around this time allows time for the food to digest without increasing the risk of a stitch or you are feeling sick.

Keep your pre run meal high in carbohydrate but low in fibre and fat as they take longer to digest and may increase the risk of GI distress. High carbohydrate snacks such as cereal bars, sports drinks, and fruit in the 60 to 90 mins before race start help keep fuel stores topped up.


  1. Use the next few weeks to practice with different meals and quantities to help you work out what’s best. Every runner’s nutrition strategy is different, some foods work better for some than others so please focus on your nutrition rather than copying others.
  2. PRACTICE YOUR RACE STRATEGY AS MUCH AS POSSIBLE – during high intensity exercise such as running, runners are susceptible to ‘runners’ gut’ due to the physical movement of the stomach and intestines, physiological strain due to a reduction in blood flow to the intestine as well as nutritional factors such as hydration, fat, and protein. I will talk more about ‘runners’ gut’ in another blog coming up.

In the next blog I shall discuss the nutrition during the race itself or the rest of your long runs.

About James

James is a Sport and Exercise Nutritionist. He has an MSc in Sport Nutrition from Loughborough University and a BSc in Sport Science from Brunel University. He is listed on the Sport and Exercise Nutrition register (SENr) too. James works with a range of athletes across a range of ages including rugby, football, golf as well as lots of runners too. You can find out more about James and what he does via his you can follow him on Instagram and Facebook: JamesFlemingNutrition
or get in .

Shopping Cart

Announce discount codes, free shipping etc