Eliza's headline numbers
Eliza's strategy
Fueling
T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
T - 15mins: Took in a final dose of carb
"I felt great all day energy wise, which I think was helped by a fantastic carb load the day before. I had energy the whole race and felt like I could have kept going!"
Underfueling during marathons has been quite common in the past, as research published in 2012 showed that 73% of marathon runners didn’t meet or exceed 30-60g/h during their races. Given the known performance and recovery benefits of carbohydrate intake, Eliza went through our Fuel & Hydration Planner to discover her recommended intake (60g/h) for this event. Although this amount of carb intake is *relatively* low compared to some of the intakes we’ve observed well beyond 90g/h in endurance events, it still often requires diligent gut training to avoid GI issues on race day. After learning her target, Eliza has practised eating and drinking at race intensities and almost completely avoided stomach issues on race day. However, at one point she did notice some GI discomfort but appropriately reduced her intake slightly to avoid worsening any symptoms. As her stomach settled, she knew to bring her intake back up to ensure she kept energy coming into her working muscles until to the end.
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.
Eliza532mg/L
Eliza 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 Eliza's losses are on the low side, getting her hydration strategy right is still important if she wants to perform at her best.
Learn moreDrinking a strong electrolyte drink before the race could have helped Eliza start optimally hydrated
"I never felt thirsty during this race, a stark difference from my last marathon in Sydney where it was 30ºC so I think I did a good job which was made easier in these much cooler conditions. "
With the drastic difference in temperature between this race and her first 42.2km run at the Sydney Marathon in 2023, Eliza had to adjust her hydration strategy. She carried one Soft Flask filled with a PH 500 (Tablet) and used the on-course hydration stations to refill the flask when necessary to ensure she always had water available. Although Eliza knows she loses quite a low amount of sodium in her sweat, she still has room to take on more sodium to better match her sweat losses and retain more of the fluid she’s drinking during the race. Using Electrolyte Capsules is quite common during road races where water is readily available on the course and it’s impractical to carry large amounts of pre-mixed water and electrolytes, so this could be a viable strategy for her in the future.
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.
Consuming caffeine in the hours before the start may have increased perceived energy levels
Despite the best evidence suggesting that substantial performance benefits can be seen with doses between 3-6mg/kg of caffeine, Eliza chose to avoid caffeine in the race given she has experienced negative side effects with large amounts of the stimulant, particularly when consumed without real food.
How Eliza hit her numbers
Here's everything that Eliza ate and drank on the day...
Final thoughts
“Having a simple time-based strategy made it easy for me to hit the carb goals as and when needed. Having a flask of water was handy so I could wash things down in between aid stations which meant I did not have to wait for water at the chaotic aid stations. ”
“Eliza built up to and performed well for her big goal of completing the 2024 Berlin Marathon. Her planned, practised fuel and hydration strategy meant that she was able to hit her carb targets without too many GI issues, and even when they did arise, she was able to adjust her intake down to avoid any significant impact, wisely bringing them *back up* when she could. Next time, Eliza could bring additional sodium with her to better match her losses, especially for warmer races where her sweat rate is likely to be higher.”
PF&HEliza's 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).