IRONMAN® World Championships

Scott went into the race with a very clear carbohydrate target of 100 grams per hour. He started the day by topping up his liver glycogen stores by pre-fueling with some cereal, a banana, and a PF 90 Gel mixed into a 500ml bottle. This left him well-fueled but not overly full ahead of the swim. In the final 30 mins before the start, he consumed a PF 30 Gel to increase his blood glucose levels and ensure he was starting with maximal energy.

On the bike, Scott relied heavily on a strategy he had practiced in training. Each of his six pre-made one-litre bottles contained a PF 90 Gel and a PH 1500 (Drink Mix) sachet, delivering both carbs and sodium in one go; a ‘coupled’ nutrition strategy. He started the bike course with three of these bottles locked and loaded onto his bike, and the following three were in his personal needs bag, which he picked up around half way. Over the course of the ride, this gave him ~630g of carb, which works out at ~106g/h, and almost perfectly matching his pre-race target of 100g/h. On the run, his carb intake dipped slightly, but he still averaged ~95g/h through a combination of PF 30 Gels mixed into his two pre-made soft flasks. He had additional carbs through cola at nearly all the aid stations along the Promenade Des Anglais and a few orange segments to stave off flavour fatigue and give him a mental boost.

By the end of the day, Scott had consumed just over one kilogram grams of carbohydrate in total, ensuring consistent energy availability and positively, he had no GI issues - a true reflection of his disciplined effort in gut training.

Previous sweat rate testing data showed Scott lost ~1.1L/h during some training sessions in similar conditions to those he faced on race day in Nice, and with a sweat sodium concentration of 1167mg/L, Scott knew hydration was going to be a critical factor on a hot and humid course in Nice. He set a goal of drinking around a litre per hour across the race to ensure he stayed on top of his losses.

On the bike, he executed this perfectly, using seven bottles; six of which contained PH 1500 and one bottle of plain water. On the run, his strategy became a little more dynamic, and he sensibly adjusted it based on the availability of aid stations, the increasing temperatures, and his perception of thirst. Scott alternated between water, cola, and PH 1000 from the aid stations to stay as hydrated as he could throughout.

Interestingly, after weighing Scott before the race and just after, we were able to understand what level of dehydration he finished at. He raced for ~11 hours, drank a total of ~10.3L, consumed ~1kg of carbohydrates and still lost 1.5kg, which equates to a total sweat loss of ~11.8L during his race. If we assume he peed a couple of times throughout, it’s likely he lost another 1L of fluid, taking this total to nearly 13L! The change in pre and post body mass showed a ~2% drop. Given that not all of this body mass loss will have been from fluid loss, it’s likely Scott maintained his hydration status very well, and avoided the known performance decrements associated with incurring >2% through dehydration.

Scott began the day with a caffeine dose alongside his breakfast, and then waited until the run to have his next dose. Early in the marathon, he took a PF 30 Caffeine Gel to help sharpen focus and keep perceived exertion manageable as fatigue began to build. Later in the race, he supplemented this with cola from aid stations, which added smaller amounts of caffeine alongside additional sugar and fluid. However, the literature suggests that the well-established ergogenic benefits of caffeine aren’t typically seen with doses below 3mg/kg, so in this case it’s likely the carbohydrates played more of a role in Scott’s well-perceived energy levels than the caffeine. Given this, to refine his caffeine strategy, Scott could either drip-feed caffeine across the bike and run, or save it until the run as he did, but ensure he reaches at least the minimum effective dose. For Scott, this might look like taking ~three PF 30 Caffeine Gels across the marathon to push him into the evidence-based range and unlock the full performance benefits of caffeine.