In this episode of the NDURANZ Podcast, we break down fat metabolism, fasted training, and whether burning more fat actually improves endurance performance. We also discuss fat adaptation, metabolic flexibility, and why athletes should focus less on fat-burning numbers and more on training quality and fueling appropriately.

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

How do Type 1 athletes actually fuel long days? Sports physician Dr. Simon Helleputte joins us to show how to hit 90–120 g/h with T1D. He explains when to trust your CGM, how to adjust insulin, and how to minimize hypoglycemia without compromising speed. We also tackle the big worry: do gels and sports drinks cause Type 2 diabetes?

How do elites actually fuel long days in the mountains? Sports dietitian Rebecca Dent from Elite Trail Team joins us to share practical ultra-trail nutrition, from how many carbs per hour to aim for to when “just one more gel” is the right move. We also discuss how to balance gels, chews, and real food without wrecking your gut and present a simple low-residue approach for the day before the race.

Former pro turned sports director Sam Bewley takes us inside the Tour de France team car — from strategy and fueling to the chaos of convoys and split-second decisions.

Forget the one-size-fits-all fueling strategy. In this episode, Alex Rhodes and Dr. Tim Podlogar sit down with Professor Gareth Wallis to explore how personalized carbohydrate fueling is changing the game for endurance athletes.