IRONMAN® World Championships

Having worked with Luke since 2021, we saw him consume his highest carbohydrate intake during a full distance race. By implementing his fuel and hydration strategy in key sessions continually over the years, Luke has built his carb tolerance from ~65g/h in hot conditions at IRONMAN® Western Australia to ~82g/h on average in Kona. The big increase came on the bike with Luke consuming ~122g/h, mainly in the form of PF Flow Gel and PF 30 Caffeine Gels. One small hiccup came when Luke, who was keen to front-load his fueling on the bike, accidentally consumed nearly half of his concentrated Flow Gel Bottles under 2 hours into the bike course and began to feel nauseous. After noticing these symptoms, he quickly pivoted and slowed his intake to get back on track with his planned consumption and set himself up nicely going onto the run.

Race Hydration: Luke worked closely with Dr Lindsey Hunt from the PF&H Sports Science Team in the lead up to Kona to help estimate his fluid losses on race day. In the build-up, they used his target pace, forecast conditions and other individual metrics to construct fluid intake targets that were designed to limit his dehydration to within 2% bodyweight change. Luke's physiology means that he loses a very high concentration of sodium in his sweat and has high rates of sweat losses, especially in warm and humid conditions. Together, these factors mean he is at a higher risk of hydration-related issues if he’s not on top of replacing lost fluid and electrolytes, which unfortunately have occurred in previous IRONMAN® races. He stuck to his extreme hydration plan in Hawaii by repeatedly refilling his 700ml bottle on the bike, slowing to take ~300ml at each aid station on the run throughout. His average fluid intake was the highest we have seen across all full distance races in our Case Study Database to this point, but crucially he maintained a high relative sodium concentration by using PH 1500 (Tablets) and Electrolyte Capsules throughout the race.

Cooling strategies: Luke utilised every aid station on the course to counteract the hot and humid Kona conditions by pouring water on his helmet/head, and filling his tri-suit with ice on the run. Luke wore a CORE temperature sensor which allowed him to monitor his temperature throughout the race on his bike computer and watch while running. We can see the points when he slowed down (via his dips in heart rate) to grab water for hydration and cooling. As Luke came into T2, he had a reduction in core temperature as he eased off the pedals before the run. Although Luke didn’t run as fast as he originally intended, he was able to adjust his pace to manage his body temperature, sweat losses and subsequently finish the race well and get him safely to the finish line.

By consuming eight Caffeine Gels across the race, Luke more than doubled the recommended dosage. Whilst the race is much longer than caffeine’s half-life and going above the recommendations is often down to an individual’s tolerance, recent evidence has shown an acute 5mg/kg dose of caffeine compromises thermoregulation in the heat and even negates the performance benefits of the stimulant, particularly for those who are regular caffeine users. This doesn’t mean Luke should remove the stimulant completely, but given no further ergogenic effects have been shown from higher doses, Luke may want to swap out a few PF 30 Caffeine Gels for PF 30 Gels in future hot races.