Simon Glastonbury
IRONMAN® World Championships
Simon's headline numbers
Simon'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.
Simon won a case study as one of the first 10 people to book a Sweat Test at the IRONMAN® World Championships expo in Kailua Kona, Hawaii. His carb intake was centred around PF 30 Chews and bolstered by the additional carbs in PH 1500 (Drink Mix). Although he got close to the recommended 75g/h target on the bike (~55g/h), he fell short on the run (~45g/h). Especially towards the end of the run, this lack of carbohydrate availability may have contributed to his fading energy levels. In future races, he should try to carry some additional carbs with him on the run to ensure adequate energy is available even near the end of the race so he can finish strong.
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 Simon’s losses are on the low side, getting his hydration strategy right is still crucial when it’s hot and/or humid as his higher sweat rate in these conditions can result in significant net losses over the duration of a race.
Learn moreSimon started his morning by preloading with a strong electrolyte drink (PH 1500) to help him start optimally hydrated. On the bike, he topped up his bidons with plain water and then added a PH 1000 (Tablet) to ensure he was hitting his sodium goals. After his Sweat Test, Simon learned he wasn’t a very salty sweater, so he paired stronger electrolyte products with extra fluid from aid stations to dilute these down and match his sweat sodium losses. Although his overall relative sodium concentration was very close (595mg/L) to his sweat concentration (573mg/L), the relative concentration of his drinks during the bike (861mg/L) was significantly higher than on the run (236mg/L). In future, he may benefit from slightly reducing the concentration on the bike and bringing along some Electrolyte Capsules to support his sodium needs better on the run instead of allowing such a massive drop-off that may have negatively impacted his hydration status.
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.
Simon may not have fully optimised his performance as he didn’t consume any dedicated forms of caffeine. He only had a small amount from the cola during the run which likely wasn’t enough to improve his performance as the dose was below the recommended 3-6mg/kg for performance enhancement. He should consider trialling caffeine use in training ahead of future races to see if it is right for him.
How Simon hit his numbers
Here's everything that Simon ate and drank on the day...
Simon's weapons of choice
Final thoughts
PF&HSimon'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.