I enable endurance athletes to overcome lack of energy and gut upset so that they can fuel their bodies with confidence and race to their full potential. Subscribe to my weekly 'Fuelling with Purpose' newsletter to receive endurance nutrition insights directly in your inbox.
Fuelling With Purpose — 15 September 2026
💡 Fuel For ThoughtThe runs you didn't train for 😬You may have seen the footage from HYROX over the weekend. An athlete experienced a very public bowel accident during the race, continued competing and ultimately won. There has been plenty of debate about what she or the organisers should have done. That’s not what I want to focus on. We also don't know what actually caused the episode. She may have been unwell, or other factors we don't know about may have been involved. What it does highlight is something very relevant to you: your gut can become one of the biggest limiting factors on race day. Physical activity, especially when racing, places a lot of stress on the digestive system. Blood flow is prioritised to working muscles, your whole body is bouncing, and intensity, heat, dehydration, and nerves can all worsen symptoms. When diarrhoea suddenly strikes, it rarely is from the gel or drink you consumed five minutes earlier. What you ate in the hours, sometimes even the day, beforehand may also be contributing. That’s why recurring race-day gut issues deserve investigation, not just acceptance. If diarrhoea, cramping or repeated toilet stops are a familiar part of racing for you, look beyond the food you consume during the event. Your pre-race fibre and fat intake, caffeine timing, hydration, food intolerances, overall strategy and even the conditions you’ve practised that strategy in can all matter. Most importantly, don't respond by becoming scared of food or cutting more and more things out. This is where personalised support can make a real difference. When gut issues keep happening, it can be difficult to know which variable actually matters, what to change first, and whether your current strategy is helping or making things worse. A big part of my work with athletes is helping them identify likely triggers, build a fuelling plan they can tolerate, and test it properly before race day. You can never guarantee a completely trouble-free gut. But recurring GI problems aren't something you simply have to put up with because you're an endurance athlete. 🚀 Endurance Highlights1️⃣ Carbohydrate availability: Why eating enough carbs mattersInterestingly, within just a few weeks of each other, two studies were published looking at carbohydrate availability from opposite directions. Together, they help separate the effects of not eating enough overall from not eating enough carbohydrate specifically. In this first study, 16 active adults spent four days in low energy availability while consuming either lower or higher carbohydrate. Higher carbohydrate intake did not completely “protect” them from underfuelling, but it did significantly reduce the drop in IGF-1, a hormone involved in growth and tissue repair, and appeared to soften some other hormonal changes. The second study showed the other side of the picture. Eight trained men ate enough calories to remain in energy balance, but four days of very low carbohydrate still reduced muscle glycogen, increased a marker of bone breakdown and produced changes suggesting a less anabolic muscle environment. Taken together, these studies suggest that energy availability and carbohydrate availability are related, but not interchangeable. Eating enough carbohydrate may soften some of the hormonal effects of short-term underfuelling, while eating enough total energy does not necessarily prevent all of the consequences of very low carbohydrate availability. 2️⃣ What happens to the body after running 30,000 km?This case study followed a 49-year-old ultra-runner who covered 30,303 km over 444 days. The most fascinating part is how closely researchers followed him, tracking his body composition, muscle function, blood markers, injuries and gut bacteria during the challenge and for up to 17 months afterwards. Despite eating around 5,800 kcal and more than 600 g of carbohydrate per day, his muscles still showed signs of ongoing stress. His muscle strength dropped by around 25%, while jumping ability and power fell by up to 50%. Markers of muscle damage also stayed high throughout the challenge. Interestingly, almost all of his muscle fibres were slow-twitch, while testosterone and haemoglobin stayed relatively stable despite the huge training load. The recovery was just as interesting. Strength had mostly returned within 10 months, but some measures of explosive power were still below where they started 17 months later. This is, of course, only one exceptional athlete, so we cannot assume the same would happen to every ultra-runner, but it gives us a rare look at how extreme endurance exercise can affect the body, and how long recovery can continue after the running stops. 🕵🏻♀️ Retail Finds*This week's product review: Aunt Betty's Creamy Rice DessertRice cream can be a great carb-dense choice during ultras. Features & beenfits
Things to keep in mind
Final take This product can be a convenient addition to your race rotation, adding a change in flavour and texture, or you can enjoy it as a pre-training snack. 👩🏻🍳 Kitchen CreationsI'm committed to sending the most valuable endurance nutrition newsletter. I want to make sure that every piece of content you receive includes information that helps you on your journey toward achieving your personal best. Happy fuelling! Gaby | Endurance Nutrition Specialist 🏃🏻♂️ Want to work together?When you’re ready, here are 3 ways I can help you:
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Gaby Villa
I enable endurance athletes to overcome lack of energy and gut upset so that they can fuel their bodies with confidence and race to their full potential. Subscribe to my weekly 'Fuelling with Purpose' newsletter to receive endurance nutrition insights directly in your inbox.
💡 Fuel For Thought The performance gap hiding in plain sight A client recently pointed out that I talk about low energy availability quite a lot in these newsletters. They’re right. And believe it or not, this is me trying not to talk about it all the time. The reality is that energy availability sits underneath almost everything we care about as endurance athletes. You can have the perfect recovery shake, the latest supplement and a meticulously calculated race-fuelling plan, but none of...
💡 Fuel For Thought Nutrition lessons from Project 168 Wow! What an incredible experience. There are so many things I could unpack from Project 168, but as promised last, I’m going to stick to the nutrition lessons for now. When I first met Phil Gore, his nutrition strategy was fairly simple: meals every few hours, with snacks here and there depending on how he felt. His energy intake during racing was very low, and at the time his backyard ultra PB was 51 yards. Several years later, Phil has...
💡 Fuel For Thought Three lessons from inside Project 168 crew tent The last few days have been particularly unusual for me, as I've spent most of my time crewing Phil Gore as part of Project 168. That’s also why this week's newsletter is a little different to the usual. With the event still unfolding, I thought I'd share a few observations from inside the crew tent, along with lessons you can adapt to your own events. 1. Clear communication makes everyone’s job easier. Phil isn't afraid to...