{"id":19391,"date":"2025-06-12T00:00:00","date_gmt":"2025-06-12T00:00:00","guid":{"rendered":"https:\/\/www.scienceinsport.com\/sports-nutrition\/?p=19391"},"modified":"2025-06-12T00:00:00","modified_gmt":"2025-06-12T00:00:00","slug":"how-to-fuel-an-ultra-marathon","status":"publish","type":"post","link":"https:\/\/www.scienceinsport.com\/sports-nutrition\/how-to-fuel-an-ultra-marathon\/","title":{"rendered":"How to fuel an ultra marathon"},"content":{"rendered":"\n
\"Renee<\/span>
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How to fuel an Ultra marathon<\/h1>\n<\/div><\/div>\n\n\n\n
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\n Written By<\/span>\n

Renee McGregor<\/h3>\n

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3 minutes<\/div>
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Nutrition is an integral part of performance. Most runners on a marathon start line will know of the importance of carbohydrate loading ahead of the event and most will have practiced with gels, carbohydrate drinks or chews, aiming for around 60-90g of carbs per hour for distances taking over 2 hours, to prevent their glycogen stores from depleting completely and hitting the wall.\u00a0<\/p>\n\n\n\n

While running has always been popular, until recently, the peak distance most runners would work up towards would be the 26.2 miles of the marathon. However in the last decade we have seen ultra distance running events spring onto the scene and now there are so many opportunities to not only go beyond the marathon distance but there are also running events and races over many different terrains from road, desert, trail, mountains and altitude. <\/p>\n\n\n\n

Fuelling beyond the marathon – is it really that different? <\/strong><\/p>\n\n\n\n

In general, the basics of sports nutrition still stand. For events that are going to take over 2 hours to complete, it is recommended that you aim for 60-90g of carbs per hour. However, how you take this can vary depending on the terrain you are running on. It is important to remember that running on road is likely to be a lot faster than running on sand or altitude or even over technical ground. So while a 50km run may not seem that much further than a marathon, times will vary significantly even if the perceived effort over the distance is the same. <\/p>\n\n\n\n

Everyone will have their own personal preference when it comes to race day nutrition. It will also depend on the type of race – supported, unsupported; at altitude or in the desert; hot or cold; road or trails; single day or multi day and how long each day will be.<\/p>\n\n\n\n

That said, ideally fuel needs to be in the form of glucose and fructose; key fact, the body can absorb around 60g of glucose per hour and 30g of fructose. There are some new studies emerging that suggest that this upper limit of 90g in total, could be increased to 120g in some athletes who train their guts but presently the sample sizes used have been small and only done in men running at altitude, so for now until we have more robust studies, I tend to recommend sticking to an upper limit of 90g of carbs per hour. <\/p>\n\n\n\n

However, what we do know is that during these longer events, especially if the terrain is undulating and constantly changing, there is more of an opportunity to use real food options. <\/p>\n\n\n\n

The longer the duration of the run, the more beneficial it can be to include some real food options as relying on gels and carbohydrate drinks alone for hours on end can lead to taste fatigue, meaning you may start to avoid taking on nutrition which will impact performance. <\/p>\n\n\n\n

Some common mistakes that I see regularly include:<\/p>\n\n\n\n