💡 Fuel For Thought

The science and art of open water fuelling

While much of the ultra-endurance nutrition conversation typically focuses on running, swimming is an area that deserves far more attention, especially when we shift from the pool to open water.

Open water swimming brings a unique set of fuelling challenges, largely because eating and drinking in the water isn’t exactly straightforward. You can’t just reach into a vest pocket or grab a gel at a traffic light. Fuelling becomes planned and intentional, often logistically awkward, but no less important.

That’s exactly what we explored in my recent conversation on The Science and Art of Open Water Swimming Podcast, hosted by my swim coach Grant Landers. With the Rottnest Channel Swim just a couple of weeks away, the timing couldn’t be better.

Gaby Villa: Nutrition, Fuell... Feb 2 · The Science and Art of O... 33:36   ​

We talked about why swimmers are often unintentionally underfuelled, the challenges of feeding in the water, and how feeding varies with swim pace and estimated finishing time.

We also dug into practical strategies: how to think about carbohydrate targets for long swims, how to structure feeds when you might only get a few chances to take them, and why practising nutrition in training is just as important as it is on land.

If you’re swimming Rottnest (or any long open water event), this episode will help you reframe nutrition as part of your performance toolkit.

🚀 Endurance Highlights

1️⃣ Supplements in cycling: Separating hype from help in performance nutrition

When it comes to performance nutrition, supplements and products often get the most attention, even though they are only a small part of the bigger picture. This review, developed as part of the UCI Sports Nutrition Project, takes a step back to examine when sports foods and supplements genuinely add value, and when they don’t. The authors reinforce that a food-first approach remains the foundation of performance nutrition, but acknowledge that the unique demands of cycling (long durations, high intensities, limited opportunities to eat) often make sports foods a practical and sometimes necessary tool.

The review highlights that only a small number of supplements have a strong evidence base for improving cycling performance, namely caffeine, creatine, beta-alanine, sodium bicarbonate, dietary nitrate, and glycerol. Even then, their benefits are context-specific, vary between individuals, and require careful timing, dosing, and practice.

The authors emphasise that supplements and sports foods should be used strategically, to help meet energy and nutrient needs when regular foods aren’t practical, or to provide a small, targeted edge, always under professional guidance.

2️⃣ Caffeine timing and performance in hot conditions

Caffeine is well known to improve endurance performance, but its benefits in hot conditions have been less consistent. One concern is that taking caffeine before exercise can lead to very high blood caffeine levels during the race, potentially increasing physiological strain, such as higher body temperature, excessive breathing, or reduced blood flow to the brain. This study explored a different approach: consuming caffeine during exercise, rather than before, to see whether it could improve late-stage performance in the heat without those added risks.

In this study, participants cycled in hot conditions and consumed either caffeine (5 mg/kg) or a placebo 5 minutes after starting exercise. When caffeine was taken during the session, participants were able to sustain high-intensity cycling for longer before exhaustion and reported lower perceived effort earlier in the workout. Importantly, caffeine did not worsen key physiological responses often associated with heat stress: breathing rate, brain blood flow, and core temperature were similar between caffeine and placebo trials at matched time points.

While this was a small laboratory study and more research is needed in real-world race settings, it adds useful nuance to how caffeine can be used more strategically in hot conditions.

🕵🏻‍♀️ Retail Finds*

This week's product review: Nice & Natural Fruit Blocks

Gummies can be a great carb-dense, budget-friendly option. I found these ones in the muesli bar section, which was interesting.

Features & benefits

• Facts per pack (20g): 70 kcal, 15.5 g carb, 1.6g protein, 0 g fat and 2 mg sodium
• Not too sweet
• Budget-friendly

Things to keep in mind

• A bit too chewy

Final take

These gummies can be an alternative if you prefer something slightly less sweet than other supermarket options. ​​​​

👩🏻‍🍳 Kitchen Creations

​Download the recipe​​​

Carrot Cake Loaf This loaf can be a great option before your next training session, or you can pair it with Greek yogurt or mixed nuts for a balanced midday snack.

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Happy fuelling!

Gaby | Endurance Nutrition Specialist

🏃🏻‍♂️ Want to work together?

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