Introduction
When you’re running, carbohydrates are your best friend. Carbs are stored in your muscles as glycogen, and this is your body’s preferred source of fuel for exercise – especially when you’re looking to make that extra push or go that extra mile. Taking the right approach can be the difference between making your PB, or hitting the dreaded ‘wall’.
This is your definitive guide to carbs – when to take them, what type to take, and how much.
Training demands
Your carbohydrate demands are high while you are training. While you might not have the same level of carb intake as just before your marathon, your body needs plenty of fuel to power your training.
Day to day carb requirements: 3-5g carbs/ kg body weight
Training days: 5-10g carbs/ kg body weight
Simply put, carbs should take up about a quarter of your plate when you’re not training, and increase this to a third of your plate once you begin your training block.
Carb loading pre-race
When you reach your taper week, your nutrition approach will change slightly. While you might be pulling back on your training, this is a crucial time to build up as much glycogen as possible. What you do in the lead up to the race can have just as much impact as what you do on race day. Start to increase your carbohydrate intake about 2-3 days before the race. This will allow enough time to saturate your muscle glycogen stores.
In these ‘carb-loading’ days, you should be aiming for about 7-10g carbs/ kg body weight. This should look like half of your plate filled with carbs (if not more!).
Sample carb-loading meal plan
Breakfast: Porridge made with low fat milk & a banana, Bagel with Jam and Orange juice.
Snack: Smoothie made with berries, oats, yoghurt, orange juice
Lunch: Turkey sandwich with lettuce and tomato
Snack: Flapjack
Dinner: Spaghetti bolognaise
For your race day breakfast, you should be aiming for something high in carbs, and moderate in protein, about 2-4 hours pre-race. This gives your body enough time to absorb what you need in plenty of time so it isn’t sitting in your stomach, causing stomach upset. You should be aiming for carbs which are easy to digest i.e. low in fibre, low in fat. If you don’t have time to eat something this far in advance, aim for about 60g of easily digestible carbohydrates an hour before your race start, such as:
- X3 slices toast with jam
- A packet of Belvita biscuits and a large banana
- A smoothie made with banana, yoghurt, orange juice, and berries
Carbs during your race
In endurance exercise, typically you’d want to be meeting 60g of easy to absorb carbohydrate per hour to keep your energy levels optimal. This is regardless of body size! This is the most important part of your nutrition to have prepared, as trying new things during your race can lead to significant gastrointestinal problems which can affect your performance. Make sure you try out your fuelling plan during training, so that you’re not risking any issues during your race. Examples of 60g of easy to absorb carbohydrates include:
- X2 squares bars
- 9 Jelly snakes
- 2 standard energy gels (this may vary depending on the brand, check the label)
- X4 medjool dates
If you want to use sports drinks instead of more solid options, it is really important you stick to your fuelling plan. It can be very easy to miss out on a dose of carbs if you don’t feel up to drinking the amount of fluid you would need. In addition to this, this fuelling approach can result in having to carry far too much of a load. To meet 60g carbs per hour with a goal time of 4 hours, you would need to carry (and drink) 4L of a sports drink!
Carbs for recovery
When refuelling, carbohydrate intake is crucial in rebuilding glycogen stores. Typically, there is a 1-2 hour window, which results in the fastest restoring of muscle glycogen. While this is useful where you may have a follow up event or training in the 24 hours after your marathon, most people would be taking a rest after a marathon (and rightfully so!). In this case, as long as you hit your 3-5g carbs/ kg body weight in the 24 hours following the marathon, you will have the same overall result.
It can be useful to combine your post-marathon carbs with protein and fluid to enhance your overall recovery as well improve carbohydrate absorption. Examples of post marathon recovery meals/ snacks include:
- 500ml Chocolate/ flavoured milk
- Flapjack, chicken sandwich, & water
- 500ml Sports drink and a protein bar
- X2 Weetabix and 500ml low fat milk
Managing gastro symptoms
A big consideration when it comes to marathon fuelling is how to manage any gastrointestinal symptoms which may be caused by high carbohydrate intakes, or intake or carbohydrates which are harder for your body to absorb. As with the rest of your marathon preparation, the key thing is to train! By taking higher amounts of carbohydrates in the lead up to the run, your body adapts to be able to absorb carbohydrates better.
As previously mentioned, by practising your race nutrition strategy during your training, you are also ‘training your gut’ to be able to handle the high carbohydrate content. This, in turn, reduces the risk of gastrointestinal symptoms. Additionally, if something isn’t working for you, you will be able to figure that out in time to trial other options rather than risking trying something new on race day!
