IM 70.3 World Championships
Marc'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.
For an event of this length and intensity, it was vital that Marc hit a high carbohydrate intake throughout whilst keeping his stomach comfortable. He front-loaded his fuel on the bike slightly with ~115g/h before taking a little less ~107g/h on the run. Although he experienced some stomach pain between miles 4-8 (6-12km) on the run, Marc was able to relax enough that the pain subsided. In future, Marc may want to increase the number of race-intensity, high-fueling training sessions in an attempt to ‘train his gut’ to tolerate this high carb intake more comfortably.
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 Marc’s losses are High (1,146mg/L), nailing his hydration strategy remains important, even when it’s Mild.Learn more
With cool conditions in Finland (~16℃ / 60ºF) and with Marc’s moderate sweat rate, he replaced his sweat losses adequately throughout the race. As most of his fluid intake was made up of PF Carb & Electrolyte Drink Mix, his average relative sodium concentration of his intake was ~1,341mg/L. This is similar to his sweat sodium concentration (1,146mg/L) so would likely have replaced a high proportion of his sweat electrolyte losses.
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.
Marc took a PF 30 Caffeine Gel on both the bike and the run, which meant his total intake was just below the scientific recommendations for endurance sports. He will likely have received some solid perceptual benefits from this, but may wish to consider swapping his pre-race gel for a PF 30 Caffeine Gel to maximise the benefits of the stimulant.
How Marc hit his numbers
Here's everything that Marc ate and drank on the day...
Marc's weapons of choice
Marc'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.