Vermont XL FKT

A clear fueling strategy is essential for an ultra endurance event, and Mathieu had just that. He front-loaded his carb intake, consuming ~130 grams per hour during the first half of this Fastest Known Time (FKT) attempt. Through this, he felt the dose-response benefits of a high carb intake for the first 12 hours of the race. But, in the final hours of the ride, the extreme intake he consumed early on impacted his appetite and his intake dwindled to ~54g/h. The cumulative effect of muscular fatigue, heat intolerance and possible over-consumption in the early parts, on top of a race against the clock meant Mathieu wasn’t tolerating his gels very well after 16 hours. He managed to pivot his strategy on-the-fly to increase his reliance on PF Carb Only Drink Mix, which meant he continued to drip feed carbs until the end. Going forwards, Mathieu may benefit from dropping his carb intake closer to ~90g per hour consistently through the event to help him continue fueling until the end, without overwhelming his gut.

Mathieu combined PF Carb Only Drink Mix and PH 1500 (Drink Mix) in half of his bottles, and supplemented this with plain water in his hydration pack to deal with the hot, humid conditions. His fluid and sodium intake remained relatively stable throughout, even though perceptually he felt like he dropped off towards the end. While his average fluid intake was what we would recommend, he could have benefited from increasing this further as temperatures rose. Implementing other cooling strategies would have also been beneficial in these conditions. The relative sodium concentration of Mathieu’s intake fell well below his known sweat sodium concentration (Mathieu loses 1,073mg of sodium per litre of sweat) but his intake replaced just under half of that (~467mg/L). This may have further contributed to his digestion issues as sodium aids with the absorption of glucose in the small intestine, so Mathieu’s gut would have been working much harder to digest his food, which may have caused discomfort. Mathieu largely relied on his bottles to hit his carb, sodium and fluid numbers; he could benefit from ‘decoupling’ his fuel and hydration to better monitor and control what he is taking. This strategy would allow him to increase his sodium and fluid intake at times without having to raise his carb consumption simultaneously.

Saving the first hit of caffeine until later into an ultra endurance effort is sometimes used by athletes to ensure they receive the ergogenic benefit of the stimulant when they start accumulating some muscular fatigue, and so need it most. Mathieu adopted this strategy, delaying his caffeine use to battle tiredness going into the night, where his natural circadian rhythm would be peaking his melatonin levels. Recent research has suggested doses of ~200mg as a first caffeine intake in ultra endurance events to maximise the ‘kick’ and fight off sleep; once Mathieu began using caffeine, he could have increased his doses or made them more frequent to help maintain his energy levels later into the attempt when it started to feel more challenging.