IRONMAN Fuelling & Hydration: Carbs Per Hour, Sweat Rates, Bottle Strategy & Racing in the Heat (Q&A) | Ep 599

Success on IRONMAN race day is as much a fuelling equation as a fitness challenge.

This episode Coach Rob Wilby works through a batch of athlete questions on carbohydrate intake, hydration, electrolytes and bottle strategy, all framed by the recent heat spells that saw IRONMAN France cancelled, Frankfurt shortened and lots of other European races affected.

In this episode:

• Should carbs per hour be based on body weight? Why gut absorption matters more than size, the 1g per kilo starting point, where the ~100g/hr ceiling really sits, and the truth about those 150g pro fuelling stories.
• How hard to push carbs in training. The safe way to build tolerance and how to adjust intake in the heat.
• How much to drink on the bike and run. The 500–700ml/hr starting point, why sweat rates range from 300 to 1,500ml/hr, and how a sweat test plus good record-keeping in TrainingPeaks takes the guesswork out.
• Refilling bottles on course. Why you don't need to at branded IRONMAN aid stations, Rob's grab-and-cool technique, and how to carry concentrated PFH and dilute on the go for non-branded races.
• Separating carbs from electrolytes. The case for one concentrated carb bottle and one strong electrolyte bottle.
• Rob's Almere 2008 cautionary tale. Over-biking, not peeing, going hyponatremic, and coming round in the med tent with two IVs - the race that changed how he thinks about hydration for good.

Whether it's your first IRONMAN or 70.3 or you're fine-tuning a hot-race strategy, this one will help you cross the line feeling good rather than in the med tent.

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