IRONMAN 70.3® Sunshine Coast

Ben’s fueling plan at Sunshine Coast was much more aggressive than he’s attempted previously. He carried two 1L bottles on the bike, each with six scoops of PF Carb Only Drink Mix and two PH 1500 (Drink Mix) packets. This created a very strong concentration of ~106g of carb per litre, so he picked up ~500ml of plain water from the aid stations to slightly dilute it. After averaging ~149g of carb per hour during the ~45kph bike ride(!), Ben *further* increased his hourly carb intake during the run to a whopping ~170g/h. It’s worth noting that the recommendations based on scientific literature 90+g/h is usually sufficient, but we are seeing increasing numbers of highly trained athletes, like Ben, tolerate >90g/h without issue. What’s most remarkable is that he experienced no GI discomfort, and immediately after the race was able to eat a solid meal. He also woke up the following day with significantly less DOMS than he’s ever had before, supporting the theory that high carb doses can reduce muscle damage and enhance recovery.

Ben’s moderate sweat sodium losses, coupled with his high sweat rate meant that his hydration strategy should prioritise fluid intake versus a strong electrolyte concentration. He managed this well, drinking just over 1L per hour even in relatively modest temperatures (~20℃ / 68℉). He never felt bloated or like he needed to pee, which suggests he was replacing an optimal amount of his sweat losses with a high enough sodium concentration to encourage his body to retain the fluid. You can see from his full stats that his relative sodium concentration fell by almost two thirds from bike to run, but thankfully he frontloaded his intake enough that this didn’t cause any negative side effects. Ben should continue to complete sweat rate testing as he prepares for the 2024 IRONMAN® World Championships in Kona, Hawaii, where the temperature and humidity will be much higher, necessitating a more proactive sodium replacement strategy to avoid dehydration.