Nagoya Women's Marathon

Pre-race Fueling: There’s no doubt that carb availability is one of the most important factors influencing endurance performance. Since glycogen stores are finite, depletion can significantly impair performance within 90 minutes of moderate-intense exercise. To prevent this, Izzi followed a strategic approach to maximise her glycogen stores to ensure she was optimally fueled ahead of the marathon. She prioritised low-fibre, high-carb foods such as white rice and bagels in the 48-72 hours before the race to optimise glycogen storage while minimising GI discomfort. This approach ensured that any training or exercise in the final days before the race would not negate her glycogen bolstering attempts and compromise her performance.

Race Fueling: Exogenous carb intake is crucial because even with fully loaded glycogen stores beforehand, additional carbs help maintain blood glucose levels and sustain energy availability throughout. The recommended intake is 60-90g/h of carb, and Izzi executed this strategy effectively, consuming ~80g/h using pre-made bottles of PF Carb Only Drink Mix, which she picked up at the elite aid stations. Of the eight bottles she prepared, she took seven, skipping the one at 40km as she felt her energy levels were stable and she had more than enough fuel to carry her through the final 2km. Instead, in a show of sportsmanship, she passed her final bottle off to a fellow competitor. Additionally, she took a PF 30 Caffeine Gel around the halfway mark to further delay fatigue and sustain her pace.

Pre-race Hydration: To optimise her hydration, Izzi drank a very strong electrolyte drink both the night before and on race morning. Instead of using our recommended preloading protocol (1 x PH 1500 in 500ml water) she doubled up and mixed two PH 1500 (Tablets) in 500ml. Research suggests this strategy can enhance fluid retention and increase plasma volume, helping her start in an optimally hydrated state. When increasing the relative sodium concentration beyond ~1,500mg/L (mg/32oz), there is an increased risk of GI upset, but thankfully Izzi practiced using these drinks and had no issues on race day. This aggressive sodium preload also reduced the likelihood of experiencing dehydration during her marathon, as she didn’t take any sodium during the race.

Race Hydration: Fluid balance is crucial for endurance performance, as dehydration can lead to cardiovascular strain, increased core temperature, and reduced muscle function, all of which would undoubtedly affect Izzi’s race. For future races, refining her strategy further with a Sweat Test would be beneficial to provide a clearer understanding of her individual sweat sodium losses and allow us to determine if a more proactive sodium replacement plan during the race could enhance performance.

As one of the most well-researched ergogenic aids in endurance sports, caffeine plays a key role in enhancing performance. Izzi’s caffeine intake fell within the evidence-based dose range of 3-6mg/kg, strategically timed through a pre-race PF 30 Caffeine Gel and second dose just before half way. This approach likely helped maintain steady energy levels and focus throughout the race.