💡 Fuel For Thought

Your brain is running too

In the last couple of live group sessions I've had with my clients, we've been talking about the role that race nutrition plays in mindset. The actual physiological connection between what you're eating during an event and how clearly you can think, how soundly you can decide, and whether that voice telling you to stop feels like wisdom or noise.

This topic has come up because athletes keep describing similar experiences. They're deep in a race; things get hard, and instead of unravelling, they find themselves making clear decisions, managing the moment, and continuing when everything in them expects to stop. When I ask what changed, the answer keeps coming back to nutrition. Being deliberate about fuelling consistently and finding that the mental side of the race felt different because of it.

Your brain runs on glucose. At rest, it accounts for around 20% of your total energy demand, and during an ultra, where you're navigating terrain, managing your crew, recalculating your pace, and talking yourself through the hard patches, that demand doesn't drop. It climbs. When your carbohydrate intake falls behind, your muscles aren't the only system that starts to struggle. Your brain does too. The dark place athletes describe late in a race often is a fuel deficit wearing a mindset mask.

What I keep coming back to in these sessions is how empowering this actually is. Because if the urge to quit is at least partly a fuelling signal, that means it's something you can influence. Consistent carbohydrate intake throughout your event is one of the most underleveraged tools you have for staying sharp and mentally in the race.

You can't out-train an underfuelled body. And you can't out-think an underfuelled brain.

🚀 Endurance Highlights

1️⃣ Energy demands and performance determinants in an all-female 6-day ultramarathon

One of the reasons research in ultra-endurance sport is so limited is that in-field testing is incredibly challenging, but the 2024 Lululemon FURTHER event created the rare conditions needed to do it well. Ten female athletes with varying levels of experience completed a certified 6-day ultramarathon, while 28 researchers collected continuous physiological, biomechanical, nutritional, and psychosocial data throughout.

Energy demands ranged from 3,727 to 11,309 kcal, while intake ranged from 2,915 to 6,856 kcal. Despite this substantial energy deficit, blood glucose remained within normal range across the race. Exercise intensity was low, yet markers of muscle damage and inflammation were significantly elevated post-race, alongside severe sleep deprivation, with athletes averaging just 5.2 hours per night.

One notable finding was that standard physiological markers (aerobic capacity, running economy, and body composition) were similar among the top finishers. What set athletes apart was how much time they spent moving, how much they ate, and critically, how many years of running experience they had. Suggesting that in multi-day ultra-endurance events, the ability to manage fatigue and keep moving may matter more than any lab-derived fitness measure.

2️⃣ Fuelled or fooled? The science behind ultra-high carbohydrate intake

Elite endurance sport has undergone a dramatic shift in race-day fuelling, with many athletes now consuming far more carbohydrate per hour than was once considered physiologically possible. This new review asks whether the science actually supports ultra-high carbohydrate intake or whether elite anecdote has outpaced the evidence.​

The evidence for a performance benefit beyond 90 g/h is surprisingly thin. Studies consistently show that higher carbohydrate intake doesn't cause the body to conserve more of its own fuel, and performance data don't support a clear dose-response relationship above that threshold.

For most athletes, the practical message is that more isn't automatically better. The authors argue strongly for an individualised approach, noting that oxidation capacity varies considerably between individuals and that blanket adoption of elite fuelling targets is premature.

🕵🏻‍♀️ Retail Finds*

This week's product review: 32Gi Pre-race Meal

A high-carb meal is a proven strategy to boost liver glycogen stores before a race.

Features & benefits

• Facts per serve (50g): 176 kcal, 35.4 g carb, 4.7 g protein, 0.8 g fat and 57 mg sodium
• Ready in 30 seconds, only add water or milk of your choice.
• Gluten and dairy-free

Things to keep in mind

• Not low FODMAP

Final take

This product may be adequate for those seeking a practical, reliable option before their events. It's travel-friendly and easy to prepare even in a hotel room. The low-fibre, low-fat profile also makes it easier to digest. ​​​​​​​​

👩🏻‍🍳 Kitchen Creations

​Download the recipe​​​

Ricotta & Peach Baked French Toast Casserole Yes, French Toast again, but I'm sure you won't be mad at me. This one is perfect for making breakfast in advance. You can split it into smaller portions if you prefer having it as a snack.

I'm committing 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:

1. ​Take the FREE Endurance Nutrition Audit. Not sure if your fuelling strategy is working? This quick 3-minute audit will reveal exactly where you stand and what adjustments could help you perform at your best.
2. ​Book a FREE strategy call. Need expert advice on your next best step? Let’s chat! In this commitment-free call, I’ll help you identify key areas to improve and map out a fueling approach tailored to your endurance goals.
3. ​Join the Fuel To Thrive Academy. Ready to take action? My signature program gives you the ultimate fuelling roadmap to unlock your full potential in sport and life, with proven strategies that have helped endurance athletes fuel smarter, perform better and break records.