Lake Sonoma 50 Mile

Chris’ fueling plan during the Lake Sonoma 50 miler was impressive not only because of his high carb intake (~780g total), but also for how well his body handled this. An absence of GI issues at an intake beyond the traditional ceiling of 90g/h, points toward a highly trained gut. While traditional endurance fueling guidelines might not always support this level of carb intake, recent research is shedding light on just how individualised carb strategies can become. Subsequently, Chris’ dialed-in strategy and execution of it demonstrates how well he has refined this intake over several races. It’s clear that this approach works well for him and is an example of the positive correlation between high carb intakes and improved performance.

Although Chris nailed the fueling part of his strategy, the hydration elements, fluid and sodium, weren’t as seamless. Despite consuming a relative sodium concentration of ~1071mg/L (a bit higher than his sweat sodium concentration), the timing of this intake may have undermined the overall balance. When the muscle cramps set in ~three and a half hours into the race, the panicked use of five Electrolyte Capsules likely came too late to blunt the issues with neuromuscular functioning during climbing. If sodium isn’t present when nerve impulses are firing at high intensity (e.g. steep climbs), the neuromuscular system becomes vulnerable. On reflection, Chris is considering switching to Electrolyte Capsules from the start to be less reliant on his intake of fluid for sodium; it could offer a more consistent delivery and bypass the variability of thirst. He’ll still aim to drink enough to offset fluid losses, but will be able to ensure a more consistent sodium intake to stay ahead of any cramping issues. Electrolyte timing should be personalised just like the rest of an athlete’s strategy, as it will be influenced by muscular workload, terrain and an individual's sweat sodium concentration and sweat rate. With a sweat rate <2L/h, it’s likely that the rate of delivery of electrolytes early on in the race wasn’t sufficient to mitigate against cramping at this intensity of racing.