Jess Learmonth
Precision Fuel & Hydration IRONMAN 70.3® World Championship
Marbella7th, FPROJess' headline numbers
Jess' strategy
Fueling
T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
T - 15mins: Took in a final dose of carb
"My stomach and energy levels were okay, I just didn’t run well. That could have been Fred (my son) keeping me up the night before."
Thanks to plenty of gut training and practice, Jess has found the right combination of PF&H products, including PF Carb & Electrolyte Drink Mix, PF 30 Caffeine Gels, PF 30 Chews and PF 30 Gels that works well to meet her racing energy demands. She implemented this strategy effectively in Marbella, using a PF 60 Chew Bar and pack of PF 30 Chews on the bike - products that aren’t as commonly used during middle distance races but ones that allowed Jess to avoid flavour fatigue whilst hitting her carb targets. Compared to the ~69g/h she averaged at IRONMAN 70.3® Kraichgau in 2024, she averaged the recommended 90g/h here in Marbella, hitting ~97g/h on the bike before a small drop to ~87g/h on the run.
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.
Jess1064mg/L
Jess has been Sweat Tested to dial in her hydration plan
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 Jess's losses are on the moderate side, getting her hydration strategy right is still crucial when it's hot and/or humid as her higher sweat rate in these conditions can result in significant net losses over the duration of a race.
Learn moreT - 60mins: Drank ~500ml of strong electrolyte drink
"I could have probably drank more on the bike, possibly another bottle."
After getting through one bottle of PF Carb & Electrolyte Drink Mix and another of PH 1500 on the bike, Jess picked up two additional bottles of PH 1000 (Tablets) from the on-course aid stations to take her fluid intake just over 1L per hour, a solid effort to keep up with her sweat losses in the warm conditions across the hilly course. However, her intake dropped by ~50% per hour on the run, where she averaged only ~422ml/h, as she struggled to take on fluid from the aid station cups. Luckily she utilised two pro aid stations to pick up flasks of concentrated electrolytes and continue to replace some of her losses. Taking on a higher relative sodium concentration than her losses will have aided with fluid retention, but further data on her fluid losses in warm conditions suggest that a higher fluid intake alongside this could have been beneficial.
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.
T - 0-4hrs: Had a final hit of caffeine
After a tough night's sleep (thanks to her toddler Fred), Jess used a high but familiar caffeine dose, made up of five PF 30 Caffeine Gels across race day in an attempt to increase her focus and perceived energy levels. While this put her slightly above the recommended range, she has a strong individual tolerance and has used similar quantities in past races without issues.
How Jess hit her numbers
Here's everything that Jess ate and drank on the day...
Final thoughts
“It wasn’t a great day for me and the lack of sleep didn’t help, but I’m happy with 7th but slightly frustrated.”
“Jess impressively claimed 7th in the world in her IRONMAN 70.3® World Champs debut with the support of her fuel and hydration strategy. An experienced racer, Jess is well aware of her carb, fluid and sodium needs and put it into practice on a tough course to support a strong world-class swim, bike and run.”
PF&HJess' full stats
Data Confidence
We rate each of our case studies from 1-5 based on the level of accuracy, and our confidence in the data.
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).