• Fenella couldn’t have asked for a much tougher IRONMAN World Championship debut, but she mastered a demanding course and variable weather conditions to finish 8th in the world with a time of 09:09:40
• The weather played a huge role in what turned out to be a battle of attrition in St George, Utah. It was a chilly start to the race as water temperatures were ~13℃/55℉, but it warmed up as the race wore on as temperatures soared to ~35℃/94℉ on the run leg
• Fenella emerged from the swim in 2nd position, but a wetsuit zip malfunction in transition meant she headed onto the 180km/112mile bike course in 3rd
• An unfortunate 5 minute time penalty for drafting in the final 10 miles of the bike leg cost Fenella more valuable time, but nonetheless she headed into the marathon determined to enjoy the experience
• In what Fenella described as “the best and hardest race I’ve ever done”, she executed a similar fueling and hydration plan to her previous IM races, but increased her sodium intake on the run, which paid dividends in the latter stages of the race as others began to fade

Hydration

• Fenella knew that the temperatures were going to soar as the day progressed in Utah, so she focused on starting hydrated by preloading with PH 1500 in 500ml/16oz of water the night before, and by sipping on two PH 1500 tablets in 1L/32oz of water throughout the morning
• Fenella could consider dialling her pre-race intake back slightly in future races as she also drank 500ml (16oz) of PH 1000 during the morning. We’d recommend sticking to preloading with PH 1500 mixed with 500ml/16oz of plain water ~90 minutes before the start of the race (aiming to finish the drink ~45 minutes before the gun goes off) to ensure optimal hydration - any more fluid could result in unwanted visits to the portaloos!
• Having worked closely with Fenella for several IM races now, she headed into the World Championship race with a dialled hydration strategy which takes into account both her sweat sodium concentration - measured using our Advanced Sweat Test - and her sweat rate, which she recorded several times during race simulation training, both in the UK and out on the St George course
• Fenella’s sodium intake during the race was ~8,994mg in total, averaging ~983mg/hr across the entire race. In relation to the fluid she drank, this meant that the relative sodium concentration of her intake was ~1,618mg/L. Considering Fenella’s above-average sodium concentration of 1,331mg per litre of sweat, she did a solid job at replacing her losses
• Fenella increased her sodium intake compared to previous races, including Challenge Roth and IM Mallorca. This proved effective in the hot temperatures in Utah (highs of 35℃/94℉)
• Fenella’s fluid intake on the bike was ~3.15L/107oz (628ml/22oz per hour), and 2.4L/85oz on the run (757ml/26oz per hour). These are solid numbers considering Fenella’s moderate sweat rate and she will have likely replaced a large amount of the sweat she lost, especially in the heat of the marathon
• Fenella has found success mixing PF 30 Gels with sodium in her bottles when racing. We’d generally advocate using solids for fuel and fluids for hydration for races of this duration, but Fenella has discovered that this as an efficient way for her to get everything she needs on board through trial and error in training, crucially without any GI issues
• During the marathon, Fenella made use of the on-course special needs where she was able to collect pre-made fuel and hydration mixes at ~10, 20 and 30km
• Fenella also took on ~400ml of energy drink, ~540ml of water and a couple of Electrolyte Capsules as she passed through the aid stations on the run. She also made sure to tip plenty of cups of water over herself during the bike and run, which will have helped her body cool more effectively in the low humidity (~12%)

Fueling

Conclusions

• Fenella raced hard on her IM World Championship debut to earn herself a solid top-10 position
• She rated her race satisfaction as a 6 out of 10, stating that “I’m happy with the result, but I’m definitely hungry for more”
• Fenella’s sodium and carb numbers were very solid, particularly the ~84g of carb per hour on the run which enabled her to run strongly right until the finish line
• Fenella said post-race that she felt like she could’ve gone quicker if a few things had gone her way, notably avoiding the wetsuit malfunction in T1 and the drafting penalty. But she told us that her 8th place position has “fueled the fire” as she heads towards another block of training in preparation for Challenge Roth next up