Simen's headline numbers
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
After consuming ~115g of carb per hour when finishing 1st male at the Badwater 135 earlier in 2023, Simen set himself the lofty target of 105g/h during the Spartathlon. Unfortunately, an unorthodox sardine breakfast - which Simen blamed for a "bubbling stomach" and diarrhoea - inevitably slowed him somewhat and reduced his gastrointestinal comfort significantly. His intake dropped from ~105g of carb per hour through PF Carb & Electrolyte Drink Mix and PF 30 Gels in the first half of the race, to closer to 30g per hour when he could only stomach one PF 30 Chew an hour, often holding them in his mouth for a while until he could swallow it.
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.
Given Simen’s losses are High (1,310mg/L), nailing his hydration strategy becomes especially crucial when it’s hot and/or humid.Learn more
Simen has had a Sweat Test and understands that he loses 1,310mg of sodium per litre of sweat. He used this information, alongside an estimate of his sweat rate in the Greek conditions having trained there two weeks prior the race, to design his hydration strategy. Initially, he was aiming to drink 1.5L of fluid and 2,000mg of sodium per hour in order to replace a good proportion of his losses. This worked incredibly well during the hotter start of the race, but as darkness fell the temperature halved and Simen’s need for replacement followed suit. At this point, the relative sodium concentration of Simen’s drinks would have been too high had he continued consuming 2,000mg of sodium per hour, so we lowered this accordingly (and may have gone slightly too low for a brief period of time as Simen found it harder to retain fluid as he had been). Happily, this was resolved at a similar time to his GI distress improving which allowed Simen to run a really strong finish during the most isolated and quiet hours of the night.
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.
Simen typically has a very high caffeine intake day to day, drinking up to a litre of coffee every morning! Having completed this race twice before, he decided to abstain from his usual habits, saving caffeine for the very end where he felt it would have the most benefit on his mood and performance. He only consumed two PF 30 Caffeine Gels and got the rest of his caffeine from cola, however this still put him just within the general recommended amount of caffeine for optimal performance. Had Simen’s stomach felt more robust during the second half of the race, we would've introduced caffeine gels slightly earlier - however we felt it was best to let his gut settle for a while before finishing strong with an added ergogenic boost.
How Simen hit his numbers
Here's everything that Simen ate and drank on the day...
Simen's weapons of choice
Simen's full stats
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.