Jack Davis
Precision Fuel & Hydration IRONMAN 70.3® World Championship
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 took on ~107g/h of carbohydrate during the Precision Fuel & Hydration IRONMAN 70.3® World Championship, which is an impressive ~37g/h higher than what he consumed at IRONMAN 70.3® Swansea in July 2025 and which is his highest ever race intake. Jack’s extensive gut training in the build up to Marbella allowed him to consume over 120g/h on the bike and ~101g/h on the run, all while maintaining a GI comfort rating of 10/10. Similarly to his previous races, PF 300 Flow Gel and PF 30 Caffeine Gels were Jack’s go to fueling products, keeping his plan simple and ensuring he had high energy levels for the majority of the event, plus a big smile on his face.
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 moreTo aid water retention and increase his blood plasma volume, Jack preloaded the night before and morning of the race with PH 1500. From pre- and post-race body weight measurements, Jack experienced a -2.6% change over the race which is likely just on the threshold of his body’s tolerable level of dehydration. To prevent excessive dehydration, Jack started with PH 1500 in his bottles on the bike before switching to the PH 1000 from aid stations, leading him to an average of ~1175ml/h of fluid at a concentration of ~1136mg/L. This was impressive considering the elevation of the course but was also crucial to replace a good proportion of his sweat losses. On the run, Jack’s fluid intake decreased to just ~363ml/h, which is quite low. Although a reduction in intake is expected when relying on aid stations, this falls below the average intake of 535ml/h we’ve seen in our case study database for middle distance triathlon runs. However, his sodium intake stayed high as he took 3 Electrolyte Capsules alongside the on-course PH 1000 meaning his relative sodium concentration on the run was higher than his sweat sodium concentration. Despite this, Jack was happy with his hydration strategy overall, and over an event of this duration, a slightly high sodium intake was not an issue and was actually probably a positive thing considering the conditions and his high total sweat losses!
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’s caffeine intake fell perfectly within the recommended range of 3-6mg per kilogram of body weight for an event of this duration. His doses of the stimulant came from four PF 30 Caffeine Gels, two more than he had in Swansea, to provide ergogenic benefits and power him through to the finish line.
How Jack hit his numbers
Here's everything that Jack ate and drank on the day...
Jack's weapons of choice
Final thoughts
Jack
PF&HJack's full stats
Data Confidence?
There is good confidence in the accuracy of the data reported. An athlete feels that the numbers closely reflect what they consumed despite a couple of estimations which may carry some degree of error. The majority of what was consumed is recorded to a high level of specificity (most volumes are known through the use of bottles brands quantities flavours). The numbers are very plausible and align with previous data recordings (if an athlete has collected data previously).