IRONMAN® World Championships

Claire’s fueling strategy on the bike consisted of PF 30 Gels and Carb & Electrolyte Drink Mix, plus five energy bars to achieve an impressive ~97g of carb per hour. On the run, her intake dropped to ~42g per hour, using just PF 30 Gels and PF 30 Chews. This drop off aligns with the common trend in our Case Studies, where athletes consume more carbs on the bike, when digestion is easier, before reducing their intake on the run where the mechanics of running make fueling a bit harder. Claire could look to continue to increase her carb intake on the run to maximise her performance by incorporating some gut training into key race-pace sessions.

Without a Sweat Test to determine Claire's sweat sodium concentration, it’s challenging to precisely tailor her race hydration plan. On the bike, she had a high sodium intake (~1,539mg/L(mg/32oz)) primarily through PH 1000 and overconcentrated Carb & Electrolyte Drink Mix. However, during the run, she consumed 1.2L(42oz) of plain water without any sodium, bringing her average relative sodium concentration down quite a bit. In the future, she’d benefit from adding sodium to her run intake to maintain her fluid and electrolyte balance late into a race. Claire peed three times during the race, indicating she was taking in a sufficient volume of fluids. This gap in her strategy in Nice may have contributed to her needing a post-race IV drip, indicating dehydration. That said, she pee’d during the race suggesting possibly her fluid intake was adequate, but sodium intake was insufficient, particularly on the run. Although her average sodium intake aligned with the recommendations, she was never consuming an optimal concentration relative to her specific losses. In the future, she could aim to distribute her sodium intake more evenly across the bike and run segments to minimize the risk of dehydration symptoms, particularly during races in hot conditions.

Claire opted not to use caffeine before or during the race, despite evidence suggesting that a dose of 3-6mg/kg can provide significant performance benefits. However, caffeine's effects vary between individuals and can sometimes do more harm than good, so testing caffeine during training will be crucial for Claire to determine if it’s right for her on race day.