IM 70.3 Taupo
Rebecca'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.
Rebecca has increased her carb intake by ~11% since the start of her 2023 season at Tauranga half. Her strategy has become more flexible as a result of decoupling her carb from her fluid, and this increased fuel intake is almost certainly the outcome of her intentful effort to train her gut to tolerate more in 2023. This said, there’s still plenty of room for improvement, and she will continue to increase energy provisions for her working muscles before racing in 2024.
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 Rebecca’s losses are on the low side, getting her hydration strategy right is still important if she wants to perform at her best.Learn more
As Rebecca’s subjective feedback suggests, her high fluid and sodium numbers were adequate for a race on such a mild day. The only thing of note based on her strategy in Taupo was how significantly she ‘front-loaded’ her electrolyte intake on the bike compared to the run (1250mg/L vs 0mg/L). Across the duration of the race, her intake worked out to be appropriate for her low sweat sodium concentration, but could be an area to work on in future races. Having a more evenly spread intake would allow Rebecca to have more control over adapting her strategy on the fly if races are warmer or cooler than expected. The easiest way to implement this would be by swapping her PH 1500 for PF Carb & Electrolyte Drink Mix which contains slightly less sodium (but has the added bonus of additional carb) when on the bike, and then carry some Electrolyte Capsules with her out of T2 onto the run course.
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.
Rebecca likely got the maximal ergogenic benefit from caffeine during this race, having hit the top end of the general recommendations by using PF 30 Caffeine Gels, with her coffee from breakfast influencing her perceived exertion and alertness for the 6:15am start. The timing of her caffeine intake on the run (allowing ~45 minutes for it to peak in the bloodstream) also meant that she would have been gaining the most benefit right through to the finish line.
How Rebecca hit her numbers
Here's everything that Rebecca ate and drank on the day...
Rebecca's weapons of choice
Rebecca's full stats
There is some confidence in the quantities and brands of products consumed but the data may lack specifics (e.g. volumes specific flavours). A high number of estimations have been made and the room for error is moderate-high. There may also be the possibility that some intake has been grossly over- or under-estimated.