Jocelyn'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.
At her last race of the 2023 season, Jocelyn implemented a straightforward, well-practised fueling strategy. Her carbohydrates came from PF Carb & Electrolyte Drink Mix and PF 30 Gels, as well as on-course gels and energy drinks. Jocelyn typically relies heavily on energy drinks for carbohydrate supply, but at this race she was targeting a lower fluid intake than she normally does, so she proactively picked up gels on-course to reach ~89g/h on the bike. This strategy allowed her to hit the same total average carb as Hawaii, but with a more consistent intake throughout the bike and run, which is a current common trend in our full distance triathlon case studies.
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 Jocelyn’s losses are on the low 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 more
After experiencing swelling in her extremities throughout the run in Kona, Jocelyn sat down with the PF&H Sports Scientists and a nephrologist friend of the team to discuss what happened and what changes she could make to avoid this in Florida. With predicted cooler conditions, Jocelyn reduced her overall fluid intake, closer to what she did at IM Texas earlier in the year. She drank just over ~1L/h on the bike and ~1.9L total on the run, compared to ~1.4L/h and ~2.4L in Kona. She took on a similar sodium concentration to her previous races to match her sweat losses, which meant less total sodium due to her lower fluid intake. Jocelyn peed once on the bike which indicated she had ‘filled the tank’ but then started to feel some swelling. She stuck to the plan of backing off her intake for the first 5-7km of the run and started to feel much better. Jocelyn treaded the line with her relatively low fluid intake on the run considering her predicted high sweat rate (in warm conditions this can reach upwards of 2L/h), even ignoring some signs of thirst towards the back end of the race. To further hone in her fluid intake on the run, Jocelyn should collect sweat rate data when running in a range of conditions at race intensity to help set intake guidelines.
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.
Jocelyn consumed slightly more caffeine than in previous races, including a PF 30 Caffeine Gel on the bike and run. However, as an individual with a high caffeine tolerance competing in an event of this duration, it was an appropriate dose to elicit ergogenic effects. It was slightly above the general guidelines, but Jocelyn experienced no negative side effects during or after the race so we wouldn’t recommend any changes.
How Jocelyn hit her numbers
Here's everything that Jocelyn ate and drank on the day...
Jocelyn's weapons of choice
Jocelyn'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.