IRONMAN® World Championship

In the build-up to Kona, Tash left nothing to chance with her fueling strategy. The day before the race, she went all-in on her carb-load. Across the day, she had three large bowls of rice, two bananas, two packets of Percy Pig sweets (an elite choice), and almost half a jar of fruit jam, equating to ~12g of carb per kilo of body mass, hitting the upper end of the recommendations. It was a textbook carb-load based on her total carb intake, source of carbs and lack of fat and fibre, ensuring her glycogen stores were completely topped up before facing the heat and humidity of the Big Island.

That preparation extended well beyond race week. In the months leading up to Kona, Tash had dedicated serious time to gut training, repeatedly practicing high-carb intakes during her toughest sessions to ensure her stomach could handle race-day demands. By gradually increasing both her carb and fluid intake in training - often in the heat - she built a level of tolerance that allowed her to fuel aggressively and consistently without any stomach issues on the day.

During the race itself, that preparation paid off. Across her 10 hours and 43 minutes, she consumed close to 1,000g of carbohydrate, averaging ~92g/h - an essential fueling rate that kept her energy stable throughout. The infamous return from Hawi delivered the expected punishment of heat and wind, but Tash stayed composed and well-fueled, keeping an eye on heart rate and power as a measure to gauge exertion. Even as some debilitating hip pain began to affect her stride on the run, her energy never truly faded. She used each aid station as a brief reset, maintaining her fueling plan all the way to the finish.

Knowing the power of hyperhydration for racing in hot and humid conditions, Tash mixed two PH 1500 tablets in 500ml of water to ensure she started optimally hydrated. With ~30ºC temperatures on the run and humidity hovering around 70%, hydration was always going to play a critical role in Tash’s race. After several heat acclimation sessions in the Precision Performance Lab, she arrived in Hawaii ready for the challenge. Across the race, she consumed ~9.7L of fluid, combining PH 1500, plain water, and Electrolyte Capsules. That equates to ~900ml of fluid per hour while racing, nearly spot on her pre-race target.

Tash had planned to take on four 1L bottles of PH 1500 during the bike, two from the start and two from personal needs halfway through, but despite freezing the bottles the night before, the warmth made them less palatable, so she adjusted on the fly. Supplementing with Electrolyte Capsules and ice cold water from the aid stations meant the drinks were more palatable in the heat and allowed her to continue to hit her fluid targets. When she felt her hydration levels dipping late on the bike, she eased her effort, focused on cooling strategies, and quickly began to feel good again.

As a Sports Scientist, there’s no shying away from data collection in a race like this. and on the ground, Tash’s fellow Sports Scientists weighed her pre- and post-race. Her post-race weigh-in showed a drop of just 0.75kg (~1.3%), indicating excellent fluid balance across nearly 11 hours of racing. Factoring in that small mass loss and her intake across the race, her sweat rate averaged out at ~1L/h.

Caffeine played a supporting role in Tash’s performance, helping maintain focus and alertness over such a long day. Across the race she took in a huge ~12mg/kg of body weight, through PF 30 Caffeine Gels. Despite being far above the recommended intake guidelines and more than she’d originally planned, her higher intake came as a practical adjustment on the day. She had limited access to non-caffeinated gels on the bike, and so relied more heavily on the caffeinated versions to ensure she was still fueling regularly. Fortunately, the decision worked well, likely a result of her frequent use of caffeine day-to-day, and her energy levels stayed high, with no signs of adverse symptoms to the high dose (e.g., overstimulation or GI discomfort).