When you think of a 24-hour race, it's easy to imagine the physical exhaustion, the mind being tested, and the body trying to find energy where there is almost none left. But the real question is: how do these athletes manage to stay in motion for so long? A study published in Frontiers in Physiology analyzed 18 amateur runners in a continuous 24-hour race in Scotland to understand, in a very practical way, how they ate before and during the event and what that meant for their performance.
The results revealed a recurring pattern in ultramarathons: these athletes consume less carbohydrate than ideal, both in the days leading up to the race and during the event itself. In the 48 hours prior, the average intake was about 4 g per kilogram per day of carbohydrates, below the recommended amount to maximize glycogen stores. During the race, consumption was around 33 grams per hour, also below current guidelines, which suggest higher amounts and the use of multi-transporter carbohydrates to facilitate absorption and reduce discomfort.
Even with this insufficient intake, one important piece of data stood out. Athletes who consumed more carbohydrates before the race and in the hours leading up to the start covered greater distances. This reinforces the crucial role of nutritional preparation, showing that performance depends not only on what happens during the race, but also on how energetically charged the athlete is at the start of the effort. Although intake during the race also showed a positive trend, it remained well below ideal, partly due to the practical difficulty of eating on the go and the gastrointestinal symptoms that arise over the hours.
Nausea, loss of appetite, a feeling of fullness in the stomach, and discomfort were frequently reported. These symptoms make it difficult to maintain a continuous intake of carbohydrates and end up being one of the main reasons for the gap between what athletes should consume and what they actually manage to ingest. The study highlights that training the gastrointestinal tract is as important as training the body itself. Getting used to frequent carbohydrate intake is a skill that needs to be developed during long training sessions, not improvised on race day.
In conclusion, the authors emphasize that there is a significant gap between nutritional recommendations and the actual practice of ultra-endurance athletes. Improving nutritional education strategies, adjusting food choices, and training the gut to tolerate higher intake can be fundamental steps for runners to consume more carbohydrates and potentially improve their performance. For those who face hours and hours of continuous movement, nutrition is not a minor detail. It is one of the few things that truly sustains the body when the limit is reached.
