Lizzie Rayner
IRONMAN 70.3® World Championships
Lizzie's headline numbers
Lizzie'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.
With each race, Lizzie has been increasing the amount of carbohydrates she is able to consume by making small tweaks to her fuel strategy. She has gone from ~65g/h to ~78g/h, and reached an average of ~82g/h over this race. The extra ~4g/h in Taupō came from using PH 1000 (Drink Mix) and PH 1500 (Drink Mix) on the bike instead of Tablets to provide some additional carbohydrates. This meant Lizzie hit an impressive ~109g/h on the bike without issue before dropping down to ~42g/h on the run; a strategy that allowed her to achieve another personal best power output across the bike.
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 Lizzie’s losses are on the moderate 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 moreConditions were hotter than many athletes had anticipated on race day, but Lizzie had already learnt her lesson about the increased fluid requirements in warm races from her recent experience and felt in control. She drank more than at any other race this season to meet her higher sweat losses and also took on a relative sodium concentration very similar to her sweat concentration to avoid any detrimental effects on her performance. Lizzie primarily replaced her losses with a concentrated 1L bottle of electrolytes on the bike, followed by Flasks of PH 1500 and PH 1000 on the run.
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.
This year, Lizzie has found her perfect caffeine strategy and has used this same dosage and timing at every race this season. She has one PF 30 Caffeine Gel just before the swim and one on the bike to hit the scientific guidelines. Next season, she may want to test out adding in one further dose towards the end of the bike/going on to the run as there has been some recent evidence to suggest a dose of 4-6mg/kg might be more effective at enhancing performance compared to a lower dose of 1-3mg/kg.
How Lizzie hit her numbers
Here's everything that Lizzie ate and drank on the day...
Lizzie's weapons of choice
Final thoughts
Lizzie
PF&HLizzie'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.