Jack Davis
IRONMAN® World Championships
Jack's headline numbers
Jack'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.
Jack consumed ~689g of carbohydrates but averaged 63g per hour, which meant he was shy of his planned intake and also below the recommended 90g/h for a race of this duration and intensity. Jack chose fig rolls as a novel form of real food in addition to sports nutrition products, which can be satisfying and help avoid flavour fatigue during long endurance events. On the run, he relied on aid stations, and again he felt like eating solid foods as his pace slowed slightly, allowing for easier digestion. Throughout the run, Jack grabbed 5 banana halves and 3 fig rolls. Considering Jack’s low overall carbohydrate intake for this event, he would benefit from increasing his carb intake for future races to better support his energy levels over a race of this distance.
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 Jack’s losses are on the moderate side, getting his hydration strategy right is still crucial when it’s hot and/or humid as his higher sweat rate in these conditions can result in significant net losses over the duration of a race.
Learn moreJack’s hydration strategy for the 11-hour effort included Carb and Electrolyte Drink Mix, plain water, and Electrolyte Capsules. With the extreme heat (temperatures peaked at around 35℃ / 95°F), Jack likely didn’t replace 100% of the fluids lost through sweat, but this wasn’t a major concern, as the human body can handle a certain level of dehydration. Some gut training in the lead up to big races would be useful to be able to take on more fluid without the risk of stomach discomfort. However, Jack mentioned that he felt that he should’ve consumed more fluids. Importantly, Jack experienced no cramps or dehydration-related symptoms, suggesting his intake was adequate but perhaps not optimal to support performance for the conditions. To combat the high temperatures, Jack relied on a "ridiculous amount" of ice from each aid station, which may have helped mitigate some thermal strain and reduce the need for as much sweat to be produced.
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.
Jack chose not to consume any caffeine before or during the race. While there are well researched ergogenic benefits of caffeine, there is a lot of variance from person to person and consequently Jack didn’t want to risk his performance by using something he hadn’t fully tested in training. Rigorous testing in training is recommended to see if caffeine is a good supplement for you.
How Jack hit his numbers
Here's everything that Jack ate and drank on the day...
Jack's weapons of choice
Final thoughts
PF&HJack'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.