Rebecca Clarke
IRONMAN® New Zealand
Rebecca's headline numbers
Rebecca's strategy
Fueling
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
After analysing her intake during her win at the Tauranga Half around 6 weeks prior to this race, Rebecca knew she needed to increase her carb intake for maximal energy availability during this full-distance IRONMAN®. Confidently leading the race out of T1, Rebecca involuntarily donated ~500ml of PF Carb & Electrolyte Drink Mix to the bike course due to a bump in the road and had to adapt her fuel plan while riding, deciding to use the on-course isotonic sports drink to replace these lost carbohydrates. But, she still hit an impressive carb intake while cycling, which was 59% higher than her intake during the bike at her previous race. On the run, however, Rebecca initially felt a lull in energy, which may have been caused by slightly mistimed caffeine consumption. Impressively, despite a higher carb intake than she’s used to, Rebecca experienced no GI discomfort while on the bike, and only minor distress while racing at her limit on the run course.
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 Rebecca’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 moreAfter speaking with the PF&H Sports Science team, Rebecca knew that a strong electrolyte drink before her race would help her to start optimally hydrated. Unfortunately, dropping a half-finished 1L bottle of PF Carb & Electrolyte Drink Mix meant she had to use whatever was available on course to stay on top of her hydration strategy. On the run she reported feeling thirsty, which may in part have been due to her fluid intake dropping from ~1.1L/h on the bike to ~690ml/h. Along with reduced fluid intakes on the run, temperatures peaked on course at around 23 ºC (73 ºF) which further worsened her hydration status. In future, we’d recommend her to maintain a higher fluid intake on the run to help sustain her performance to the highest level, particularly in warm weather conditions..
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.
Rebecca’s caffeine intake during this race put her just above the general recommendations for performance enhancement. This ensured she maximised the chance of experiencing all of the benefits associated with caffeine. The only adjustment she plans to make in future is in regards to the timing, as she will try delaying one of her PF 30 Caffeine Gels to the end of the bike leg to see if this helps her avoid an energy dip at the start of the run.
How Rebecca hit her numbers
Here's everything that Rebecca ate and drank on the day...
Rebecca's weapons of choice
Final thoughts
PF&HRebecca's full stats
Data Confidence?
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.