If you’re tackling a marathon, you will have trained hard for months to get in great shape and ready to line up at the start of those 26.2 miles. One of the critical pieces is your marathon nutrition plan…

The Fuelling Facts

During a marathon, more than two thirds of your energy can come from carbohydrate. Unfortunately your body is only able to store a limited amount of carbohydrate and as the miles tick by, you will deplete that store. As your carb levels fall, so does your energy, and you will find it harder to maintain your early pace. You could even hit the dreaded ‘wall’ – where your carb stores are so depleted that your muscles are forced to rely almost exclusively on fat as fuel.

The body finds it hard to convert fat to energy, which makes it tough to keep running at any pace. To ensure you have optimum carbohydrate levels on race day, you should carbo load in the days leading up to your event and consume carbohydrate during the Marathon. Visit our How to Carbo Load guide for more information on carbo loading.

During Your Marathon

Think of your body’s store of carbohydrate as a relatively small fuel tank, that starts emptying as you start running. Your muscles use carbohydrate quickly and can easily deplete that store during a Marathon. If you provide your muscles with carbohydrate by consuming gel as you run, they will take less fuel from your carbohydrate store and it will last longer. The purpose of taking gel during your marathon is to delay the point at which you run out of fuel – until you cross the finish line.

It might seem logical that the more gel you can consume, the better – but take care. You can consume (read swallow) a lot of gel, BUT your body can only absorb a maximum of 60g per hour (up to 75g if the gel contains caffeine). Taking too much gel too quickly can and will cause stomach problems. By contrast, taking just a couple of gels at the 17mile mark, as some people do, will only provide a short lived energy boost. Taking 2 or 3 gels every hour from the very start of your event is optimum and will mean that by mile 17, you should have a large stock of carbohydrate available for a strong finish.

11 Minutes Faster

Recent Research at the Copenhagen Marathon showed that runners were on average 11 Minutes faster by following our marathon nutrition guide on race day with no extra training and no stomach upset.

Race Day Breakfast

Marathon Breakfast

Breakfast should be light and high in carbs. Take an Energy Bar with you to eat on the way to your race.

Novice Runners

Beginner marathon nutrition

Wait until 30 minutes from the start of your race before taking your first sachet. Take one Energy Gel Aqua Caffeine sachet every 30 minutes. Use a Gel Belt to carry your gels.

Experienced Runners

If you get your nutrition right, you will give yourself the best chance of getting that all-important new PB.

Best Marathon Running Performance

Take one gel sachet every 20 minutes during your run (3 per hour). Wait until 20 minutes into your race before taking your first sachet. If you find that 3 gels an hour is too much, try and consume as many gels as you comfortably can.

Optimise your caffeine intake

Caffeine gives you both a physical and mental boost. When taking part in a marathon, it helps to increase your endurance performance. Depending on your bodyweight, there is a maximum number of HIGH5 Caffeine Gels you should take.

Optimise caffeine for marathon nutrition performance

Practising using gel during longer training runs makes it easier to use on race day. You can use Energy Gel Aqua instead of Energy Gel depending on personal preference – they perform the same function.

At the finish

Drink 400ml of Recovery Drink as soon as you finish. Drink another 400ml one hour later and eat a balanced meal as soon as possible.


Your fluid needs will depend on how warm the weather is on race day and how much you sweat. Try to drink water or the on-course drink regularly. If you use the on-course drink, take care not to consume too much additional carbohydrate from that drink or you will need to adjust your gel intake. In very hot conditions you may need additional electrolytes. Individual ZERO tabs can be wrapped in Cling Film and carried on your run. Simply put the tab into the on-course water to make a refreshing electrolyte drink. ZERO does not contain carbohydrate.

Caffeine Note

If you have any medical condition including high blood pressure, if you are pregnant, breast feeding or under 18 years of age, do not use caffeine If you are sensitive to caffeine and suffer any side effect, such as a higher than expected heart rate, discontinue use immediately. If you do not wish to use caffeine for any reason, simply follow our marathon nutrition guidelines using gel without caffeine.

Good luck!