How to fuel for a marathon

Marathon runners are starting to pay more and more attention to their nutrition. No one ever questions the importance of training, yet the importance of nutrition has often been underappreciated. Or perhaps the topic of nutrition seems to pop up on the radar only close to the marathon.. and this is when many questions suddenly arise. In this nutrition guide we will explain how to best fuel for your marathon. What should you eat the day before, or the morning of the marathon, and what drinks, gels and solids you should take during the marathon, and how often. Keep reading if you want to know the answers.

What can go wrong nutritionally during a marathon?

A large percentage of marathon runners struggle to get their nutrition right, and many who do not have a great run, blame nutrition: they ran out of energy, became dehydrated or experienced stomach problems. They ingested too much, or ingested too little. They tried new products they had not used in training, and so on.

Here are the most common mistakes:

Not having a plan.

Just starting a marathon thinking: "oh I will drink when I get thirsty and I will grab something at feed stations if I need it". It is a gamble. Maybe it will work. If you have prepared for your race, invested so many hours training and you have planned all your training, why not plan your intake, and increase the chances of success?

Sticking to a plan at all cost

Some runners have a plan but are a little too rigid sticking to this plan. If you have a plan, don't stick to it at all cost, and don't be afraid to deviate if you have to. If the weather conditions re warmer than expected, maybe you need to drink more. If you feel stomach discomfort just reduce intake for a while.


Many runners get excited at the expo the day or days before, buy new nutrition products and will have to find out if they work in the marathon. Stick to what you have tested and to what you know will work. Don't experiment in the most important event of the year!

Three common mistakes marathon runners make.

Why is nutrition so important for a marathon?

Let’s start with the most important questions: Why is nutrition important in a marathon and what difference can it make? A marathon will take anywhere from 2-6 hours. Energy expenditure is somewhere between 2200 and 3200 kcal depending mostly on body weight Interestingly it is pretty much unrelated to pace! A runner who uses half as many kcal per minute will be running for much longer, resulting in similar total energy use.