Jess Belcher
IRONMAN 70.3® World Championships
Jess' headline numbers
Jess' strategy
Fueling
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
Jess executed a front-loading strategy, averaging an impressive ~122g of carb per hour on the bike and dropping to ~54g/h on the run. This trend is often the case with triathletes fueling strategies, as it’s often more difficult for the stomach to absorb carbohydrate whilst running due to the increased movement and usually an increase in effort. Jess has trained her gut to tolerate this quantity of carb, and came close to the 90g/h recommendationson average across the race, so some additional practice of high-carb fueling during her future run sessions will be desirable to achieve these greater intakes.
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 Jess’s losses are on the low side, getting her hydration strategy right is still important if she wants to perform at her best.
Learn moreBefore her race, Jess consumed an electrolyte drink, but unlike our recommendations it only contained 220mg of sodium which is too low for optimising an individual's pre-race hydration status. She also had some plain water 30 minutes before starting, which would have further diluted the concentration of sodium in her body. Next time, Jess should use a stronger electrolyte drink, such as PH 1500, both the night before and the morning of her race to appropriately preload. On the bike, she managed to maintain a fairly high fluid intake considering the colder weather (~7℃ / 44℉ average temperature). Similar to her hydration strategy, she front-loaded her sodium intake on the bike and tapered back to just ~100mg/L on the run. Overall, Jess appropriately replaced her sweat losses with her intake across the race to stay in line with her individual sweat sodium concentration, as determined by a Sweat Test. In longer races or when conditions are much warmer, she should look to bump up her sodium intake on the run to ensure she doesn’t have any hydration-related issues as a result of lower than ideal sodium levels towards the end of the race.
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.
Jess may want to trial some caffeine in her training sessions to introduce this into her strategy for future races, as the science suggests that it enhances performance.
How Jess hit her numbers
Here's everything that Jess ate and drank on the day...
Jess' weapons of choice
Final thoughts
Jess' full stats
Data Confidence?
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.