Fuelling the Marathon. Carb-Loading 101.


Everyone talks about carb loading, but how important really is that XXL bowl of pasta the night before your first marathon? Knowing what to eat before a long run can be confusing. The internet is full of info on running nutrition and hydration, with so much detail that it can leave you feeling overwhelmed and even more confused than you were to begin with. This post will keep things as simple as possible and hopefully help you work out a pre-run meal plan that suits you whilst maximising race-day performance.

Why is pre-marathon fuelling so important?

Our bodies can only store enough energy (in the form of glycogen) for around 1.5-2 hours of running. Continuing to exercise beyond this point increases your risk of hitting the dreaded wall (which I had the pleasure of being introduced to during last weekend’s marathon). Whilst you can ensure that your glycogen levels are topped up during your long runs with energy-boosting gels, drinks and chews; carb-loading and pre-race meals can ensure that you are on that start line with as much energy as possible.

However. “carb-loading” is often done very wrong, with people believing that they should be eating as much pasta, rice and bread as physically possible the day before the race. However, all this will end up doing is leaving you feeling heavy and lethargic, and will most likely slow you down rather than speed you up on the big day.

How long before a race should you start carb-loading & how much should I eat? 

Whilst some people may tell you to carb-load an entire week before a big race, I have found that 2-3 days works best (for me). My “normal” diet tends to be lower in carbs and higher in fat, so the sudden shift does often leave me feeling a little bloated. This took some getting used to (especially as the number on the scales starts creep up!), but I promise it won’t make you put on weight in the longer-term (your weight will be back to normal post-run) and is largely due to an increased amount of retained water.

If there is one thing you should take away from this post, it’s this: during carb loading, you should not be increasing your regular daily calorie intake. Instead, you should be just eating a greater proportion of calories from carbs; meaning less fat and less protein. For example, during carb loading, I would consider swapping my usual chicken, sweet potato and veg dinner for white pasta, chopped tomatoes and a sprinkling of parmesan. If you like to track your macros, you should aim to eat around 60% of your calories in the form of carbohydrates. If you do not actively track your calories, this is equivalent to 8g of carb per kg of body weight. Example, a 60kg person should eat 480g carbs each day during carb loading, which is equivalent to 1,920 calories.

Does this mean I should stop eating fat and protein?

In short, no. Especially protein. Fat is best reduced to a minimum in the days leading up to a race, but some protein may actually give you an extra lil’ energy boost. This is because protein slows the digestion of carbs, meaning the energy will be released more slowly; exactly what we want during a 26.2 mile run. Whilst a small amount of fat won’t do any harm, it’s best to avoid greasy, fried food in the 24 hours before a race.

As a first-timer carb-loader, you may find the whole ordeal a little tricky at first. In the days leading up to the race, you must learn to just let your health-freak, clean eating ways go (in other words, say goodbye to the kale). Whilst nutrient-dense foods offer many health and performance advantages during the training cycle, we want be as kind as possible to our digestive systems before putting our bodies through an ordeal such as a marathon. This doesn’t mean you should cut out everything green from your diet, make sure you choose starchy veg and fruit such as potatoes, peas and bananas and try and avoid high-fibre options like apples (although these can be eaten skin-off!).

So what does a carb-loading meal plan look like? 

In the 2 days before a race, I will increase my calorie intake from carbs. For these 2 days, my meals will look something like this:

Breakfast: Porridge made with almond milk, banana & honey

Lunch: Sweet potato with kidney bean chilli & peas

Dinner: Pasta with pesto and sundried tomatoes

Snacks: Energy bars (Cliff are my fave), bananas, rice cakes, bagels & PB

Eating breakfast the morning of your race is a must, just make sure you leave enough time (around 2.5-3 hours) for your food to digest. I’ve even heard of people waking up in the middle of the night, eating their meal and going back to bed for a few hours when it’s an extra early start! For me, I always have a big bowl of porridge with banana and honey as I know it sits well and won’t give my tummy any surprises. Another good option is a bagel with PB, banana and honey.

So, you should now be all set to work out what to eat and when, before your big day. Keep your eyes peeled for the next post: how to correctly fuel during a marathon, and let me know if you have any questions by dropping me an email at mybusinessbody@gmail.com.


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