Sub-3 Marathon Race Preparation: Nutrition

I ran the Chester Marathon in 2h 56min. The race review has its own blog post, but let’s also talk about preparation. And today in particular, about nutrition.

As I already mentioned, there are many things that can go wrong while running a marathon. Some of those you can’t do anything about (weather for example). But for a few, you can minimize or even eliminate the risk.


I used the loo before the start at Chester, not because I needed to go, but the queue was reasonably fast, and I wanted to zero the risk of having to wee. But I could have skipped it. And that’s because my hydration process starts a couple of days before the race. While most people enjoy their pasta, I mostly enjoy my water. I drink as much as I can, in various forms and go to the loo very often.

But the most important hydration period is the evening before the race if the race starts early in the morning. I usually eat more carbs during that evening meal, as many do, but I also drink a lot of water. Glycogen needs water to be stored. And quite a significant amount. But even without considering glycogen, I drink an especially high amount of water. That means I’m slightly overhydrated the morning of the race. But because I get enough time since I wake up till the race starts, I go to the loo and wee the excess. And no more water that day, except for a small coffee at least one hour before leaving the house/hotel. That puts my bladder in the perfect condition before the race. One less worry.


We are bombarded with processed carbs wherever we go. But they usually come with a lot of fat too and very little fibre. Because eating a big big bowl of porridge is too damn boring. So one of my strategies is I make sure I eat fueling carbs. Those can be boiled or baked potatoes, or pasta with a sauce that’s low in fat. Fat influences in a negative way how our bodies absorb the carbs. Fibre also keeps the damage of overeating at a minimum. So not having enough might mean raising the inflammation levels throughout your body. This not a post about dieting and nutrition, but just consider lowering your fat intake and increasing your fibre intake – which should be the default if eating whole foods rich in starch.

Intermittent Fasting

I’m also practising intermittent fasting, generally following a 16:8 regimen. Which means I give my body 16 hours without any food (fasting), in which time it recovers better and regulates the hormones, and then I shrink the feeding period to only 8 hours. This usually translates into having my first meal of the day after 12 pm and my last at 8-9pm. Now, again, this post isn’t about explaining in detail what intermittent fasting is, but what are the effects towards endurance running.

I had a full 24 hours cycle of fasting during the Monday before the race. The first main effect is the quicker recovery, hormonal balancing, putting my body in the perfect position to absorb a high amount of good quality carbs during the few days before the race. And also reducing the inflammation caused by the training period.

The second effect is that my body gets used to running on low blood sugar. And when you’re talking endurance, you either chuck in loads of gels and energy drinks continuously to keep your blood sugar at higher levels – the ones your body is used to – or you can keep yourself at bay from ingesting anything other than water and eliminate the risk of your body rejecting that gel or energy drink.

Another significant effect is the fact that your body becomes a lot more efficient at burning fat. It means you can build endurance without having to depend so much on carbohydrates both during training and the race. And burning fat more efficiently also keeps your weight in check throughout the training period. That’s when runners experience a higher level of hunger and tend to eat a lot more calories than needed.

However, you can’t get into intermittent fasting right away; I’ve been doing it ever since I started training back in May/June. It takes a while for your body to get used to it and stop craving breakfast. Throwing yourself directly into it will only cause damage, at least mentally.

Run on water (and a bit of coffee)

So, apart from my 24 hours fast on Monday, one other particular thing I did was to not eat anything until after the race. I only drank water at the stations, nothing more. And that helped me worry less about how would that drink or that gel or that banana or that orange interfere with my digestion and my performance. So by drinking only water and running mostly on air and fat, I was able to keep going. No hunger feeling, no wall, everything was great. I can’t wait to confirm this recipe one more time during my next marathon.

These are my main nutrition-related things I did before my marathon race, and I have to tell you, everything worked perfectly for me.

What nutrition regimen are you following for your marathon races?

How to prepare for a fast marathon from a nutrition perspective. These are the habits that halped me get a sub 3 hours marathon.

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