A guide to pre-race fuelling
Pre-marathon fuelling is one of the most important things to consider in the last few days before your race. Thankfully, as with most aspects of race-prep and training, it’s fairly easy to get the basics covered and get to the start line well fueled.
Why do you need to pre-fuel?
If you are running a marathon, it is a near certainty that your body will burn all the energy sources that are easily available to it at a higher intensity. So it is important to increase those energy stores by “carb loading” as much as possible in the days leading up.
Why “carb loading”?
The easiest and quickest energy source for your body to consume whilst operating at a higher intensity are the glycogen stores in the muscles themselves. This means you want to have the muscles full to the brim with glycogen. How do you get glycogen into your muscles? Consume carbohydrates.
Ordinarily, we are conscious of having a balanced diet for general health and well being. Prior to a marathon, you can throw those concepts out the window.
How to approach fuelling for a marathon
Timing
It starts two days before the race. You should start eating more than usual a full 48 hours before your race, not just the day before.
Assuming your race is on a Sunday, you should start carb loading on the Friday morning, and increase your intake on the Saturday. Be conscious that you aren’t continuing to fuel too late into Saturday night (if the race is in the morning) as it is important for your body to digest.
What to eat
Eat energy dense foods, with lots of carbohydrates and don’t worry so much about foods with high levels of micronutrients. Simply, forget your balanced diet and consider every non-carbohydrate heavy ingredient as the enemy. It’s difficult to consume enough calories in the lead up to a marathon to completely fill your stores, so it’s important not to waste digestion on foods which aren’t giving you a good ‘bang for your buck’.
Eat food you know, that is also low in fibre to avoid any gastrointestinal issues ahead of the race. Don’t experiment with new foods in the days before a race, just stick to what you know and what your body likes. We’re all different so there’s no golden bullet here. Some ideas for energy dense foods which are:
Bagels and peanut butter, spread thickly
Pasta
Milkshakes (the fan favourite is chocolate milk, a bar of chocolate and chocolate ice cream with optional banna if there’s room in the blender)
Pastries and doughnuts
Cake
Potatoes (mashed or otherwise)
Juice, sports drinks or Coca Cola
How much to eat
The short answer is “more than what is comfortable”, but in practice this can be difficult. In order to get as many calories in as possible — so that you’re not overstuffing yourself at mealtime — a good approach is to snack consistently in between mealtimes. If you think about eating, just eat. When in doubt, eat.
You can take a more scientific approach to quantities, but this can add additional stress ahead of the race. Better take a principled approach which should leave you in more or less the same position (without the measuring and stress).
Try and enjoy it. See it as a food binge that you wouldn’t ordinarily allow yourself… and indulge.
Example carb loads
24 hours prior to the race
Final takeaways
In many ways this is one of the most enjoyable parts of pre-race prep; it’s an excuse to eat lots of sweet, simple foods which are usually eaten only in moderation. Pre-marathon fueling is sometimes described as ‘like a 10 year old has done the weekly shop’. But don’t be fooled, to get enough energy in you’ll probably need to eat beyond the point of satiety, particularly the evening before the race.
If you’re racing a shorter distance the same rules as above still apply, but the volume of food required reduces, so you can get away with eating less for a 5k, 10k, or half marathon than you need for a marathon.
PS: don’t forget to drink water with all the other consumption. No need to overdo it. Drink to thirst.
