A new review paper by Tim Noakes has reignited the debate around carbohydrates, fatigue, and endurance performance. The paper proposes that maintaining blood glucose during exercise may be more important than maximizing glycogen stores, and that relatively small carbohydrate intakes could be sufficient to support performance.

After reviewing the arguments and the studies cited, we see several limitations in how the evidence is interpreted and how the conclusions are applied to real-world endurance sport. While the importance of blood glucose regulation is well established, performance in training and racing is influenced by multiple factors, including intensity, variability of effort, total energy demands, and recovery, making the picture more complex than a single mechanism can explain.

Science progresses through debate and critical analysis, and our aim is to examine these ideas in context and compare them with the broader body of research and practical experience in endurance athletes.

Study discussed:
https://academic.oup.com/edrv/advance-article/doi/10.1210/endrev/bnaf038/8432248

Henrique Avancini made plenty of nutrition mistakes throughout his career and learned from every one of them. Over time, he realised that nutrition is not an area where experimentation comes without consequences. Once you find what works, changing it just for the sake of change can hurt performance. Training, on the other hand, allows room for experimentation, because mistakes are easier to recover from. With nutrition, a single wrong decision can break your performance.

Fueling timing isn’t just about how much you eat, but when you take it. This discussion breaks down what the research shows when total carbs are matched, comparing steady intake with front-loading and back-loading. It covers impacts on performance, exogenous carbohydrate oxidation, and gut tolerance, with practical takeaways for building a race-day fueling plan that works in the real world.

Tim's Carb Distribution Study https://journals.humankinetics.com/view/journals/ijsnem/aop/article-10.1123-ijsnem.2025-0059/article-10.1123-ijsnem.2025-0059.xml