Kyle Smith
IRONMAN 70.3® Taupo
Kyle's headline numbers
Kyle's strategy
Fueling
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
Kyle hit ~109g of carb per hour during this race, with a large proportion of it coming from his two pre-swim PF 30 Caffeine Gels. Kyle’s fuel strategy on the bike was to carry most of what he would need to reduce his reliance on picking anything up from on-course aid stations, which cost him in Ibiza earlier in 2023. He took the two gels taped to his top tube and filled his aero bottle with two PF 90 Gels and some water, averaging ~120g of carb per hour while on the bike. This dropped off considerably for the run to ~82g/h, which is consistent with what we see in other Case Studies and still within 10% of the Fuel & Hydration Planner’s recommendation for an event of this duration and intensity.
Hydration
Taking on board an appropriate amount of fluid and sodium is essential to maintaining blood volume and supporting the cardiovascular effort needed to perform on race day.
Whilst the absolute amount of sodium and fluid consumed per hour is important, it’s critical to consider these in relation to each other. This is known as 'relative sodium concentration' and it’s expressed in milligrams per litre (mg/L). How much sodium you’re taking in per litre of fluid is more important than the absolute amount taken in per hour.
Sweat sodium concentration (mg/L) is largely genetically determined and remains relatively stable. Knowing how salty your sweat is enables you to replace a good proportion of your sweat losses, which can range from 200-2,000mg/L.
Whilst Kyle’s losses are on the low side, getting his hydration strategy right is still important if he wants to perform at his best.
Learn moreWith temperatures peaking at ~19ºC in Taupo, Kyle has certainly raced in more oppressive conditions. Because of the mild conditions, Kyle’s sweat rate and therefore requirement for fluid was very manageable. As someone with very low sodium losses in his sweat, Kyle reduced his reliance on mid-race electrolytes by frontloading his sodium with a couple of Sodium Bicarbonate capsules before the race. The quantity that he took contained the equivalent sodium (~4100mg) to nearly five and a half servings of PH 1500, which means he would have effectively achieved a relative concentration of 584mg/L, had he consumed that during the race. So, while he only actually took ~42mg/L during the swim-bike-run, we wouldn’t recommend he take any more. His subjective feedback also suggests there was no downside to executing his strategy in this way. Our only word of caution is the extreme risk of gastrointestinal issues from consuming such a large amount of sodium in one go, so to those looking to trial this technique, ensure the first time isn’t before a race!
Caffeine
Beyond the Three Levers of Performance (carb, sodium and fluid), caffeine is one of only a few substances that is proven to improve performance for most endurance athletes as it can help stave off mental and physical fatigue.
Having taken just above the general recommendations for caffeine intake across the four hour race, Kyle effectively reduced his perceived effort and increased his alertness. Happily, he reported no adverse side-effects from the caffeine, and as a habitual coffee drinker, it’s likely Kyle would have needed this high dose to maximally impact his performance.
How Kyle hit his numbers
Here's everything that Kyle ate and drank on the day...
Kyle's weapons of choice
Final thoughts
Kyle
PF&HKyle's full stats
Data Confidence?
There is an adequate level of accuracy in the data collected and the numbers reported. The athlete manages to recall what they ate and drank including most specifics (brands flavours quantities plausible estimations of volumes). However there are estimations made within the data which affect the overall confidence level in the data reported.