Rebecca Clarke
IRONMAN® Cairns
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.
Becs managed a similar carb intake to her recent races, although below the recommendations for a race of this duration and intensity. After chatting to our Sports Science Team she made a few amendments to her strategy to reduce the need to ‘chew’ some of her fuel, increasing the concentration of carbs in her bottles instead. However, she didn’t finish her ‘Fuel Bottle’ on the bike, with nearly half remaining as she started the run. Had she finished this, Becs’ intake would have been closer to her 90g/h target. Despite this, she reported high energy levels and no GI discomfort, even after struggling recently with it. Going forward, we would encourage Becs to continue gut training and practising using her ‘Fuel Bottle’ in training to be able to maintain her stomach comfort whilst reaching for the top end of fueling recommendations in an attempt to optimise her performance.
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 moreBecs has been working on increasing her fluid intake, particularly in warmer conditions like at IRONMAN® Cairns to account for her higher sweat losses. She drank ~130ml/h more on average in Cairns than previously at IRONMAN® Texas. With the high temperatures, she still felt thirsty and it's likely Becs would have benefitted from drinking more fluid on the bike, as a few of the bottles she picked up were solely used to cool herself down. Her relative sodium concentration was slightly lower than planned as a result of the extra on-course hydration bottles which contained less sodium. Although this didn’t seem significant enough to impact her performance on this occasion, as her intake still fell within ‘the green’, Becs could carry some Electrolyte Capsules to stay more in-line with her sweat sodium losses even when picking up extra fluids.
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.
Becs regularly uses caffeine in her training and races and made sure to incorporate this into her strategy in Cairns. Unfortunately, some of the caffeine she planned to consume was mixed in her ‘Fuel Bottle’ which she didn’t finish so her intake was slightly lower than previous races. However, it was still enough to reach the lower end of the recommendations and reap the ergogenic benefits of the stimulant and support her performance.
How Rebecca hit her numbers
Here's everything that Rebecca ate and drank on the day...
Rebecca's weapons of choice
Final thoughts
Rebecca
PF&HRebecca's 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.