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Leon Chevalier

Pro

IRONMAN® Cozumel

19th November, 2023
Mexico
Cozumel
1st, MPRO
Triathlon, Full distance - 222.4km
26°C
, Hot and Humid
6hrs 42mins
more race details

Leon's headline numbers

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?
?
~124
g
Carb per hour
Recommended 90g/h+
~1,143
ml
Fluid per hour
Recommended 750-1,250ml/h
~578
mg
Sodium per litre
Recommended 1200-1600mg/L
~8.3
mg
Caffeine per kg
Recommended 3-6mg/kg

Leon'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.

Carb-loaded
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T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
pre-fueled
?
T - 15mins: Took in a final dose of carb
Carb per hour
Recommended 90g/h+
~124
g
Leon's Energy Rating
9
/10
"My energy levels were great all day and never really wavered. The only discrepancy was some muscular fatigue towards the end of the bike. I felt great during the whole run. "
Our thoughts

With the swim getting cancelled close to the start time, Leon made sure he kept his circulating glucose levels high by taking small, frequent doses of PF 30 Gels until it was decided the race would be a bike-run only. The day continued to throw curveballs, as he dropped one of his water bottles containing ~170g of carb and subsequently picked up a bottle of on-course isotonic mix to replace this lost fuel. Complications continued into the run when Leon was unable to collect his bag of gels from the special needs aid station at the halfway point. He had to rely on cups of cola and a couple of on-course gels to fuel the second half of the marathon, which wasn’t ideal for him. All things considered, the amount of carb Leon did managed to consume was a testament to his determination to not under-fuel.

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.

Leon1392mg/L
Leon has been Sweat Tested to dial in his hydration plan

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.

Given Leon’s losses are High (1,392mg/L), nailing his hydration strategy becomes especially crucial when it’s hot and/or humid.

Learn more
Pre-loaded electrolytes
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T - 60mins: Drank ~500ml of strong electrolyte drink
Fluid per hour
Recommended 750-1,250ml/h
~1,143
ml
Sodium per litre
Recommended 1200-1600mg/L
~578
mg
Leon's Hydration Rating
8
/10
"I think I had a solid hydration strategy, and even though I couldn't get exactly what I wanted, my cooling strategy was excellent, and I coped with the adversity well."
Our thoughts

Leon had adapted his usual hydration strategy to account for the high temperatures and humidity in Cozumel, making sure he had plenty of sodium on board to replace his high sweat losses. However, by losing a bottle early on in the bike, he couldn’t follow through on this plan, though he did well to limit his losses with some on-course drinks. Since the sodium concentration of those drinks was much lower than what is needed for his high fluid and sodium losses, he fell well below his individual recommended amount. He also felt hungry throughout the whole race, indicating the low sodium intake may have also impeded carbohydrate absorption from his stomach into his blood. Going forward, taking more Electrolyte Capsules with him as a precaution could help mitigate the impact of tricky circumstances.

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.

Pre-caffeinated
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T - 0-4hrs: Had a final hit of caffeine
Caffeine per kg
Recommended 3-6mg/kg
~8.3
mg
Our thoughts

Leon is a big fan of coffee, and has regularly utilised the ergogenic benefits of caffeine during races. Cozumel was no exception, and with his high tolerance to the stimulant, it’s unsurprising to see him exceed the ‘general’ guidance. Since he had no adverse effects though, we wouldn’t suggest any changes.

How Leon hit his numbers

Here's everything that Leon ate and drank on the day...

Leon's weapons of choice

Final thoughts

Leon's Satisfaction Rating
10
/10
Obviously it would have been interesting to do the swim, and I could probably have dug deeper on the run to go under 2:40 again. But ultimately I had one of my best ever (if not best ever) IRONMAN performances off the back of a very suboptimal prep.
Leon
Leon’s final race of 2023 was eventful from start to finish. His experience and professionalism enabled him to navigate both the logistical and nutritional challenges with skill and claim his spot for the World Championships in Kona 2024. Shortly after the race, Leon was quite sick from all the cola he had consumed, as this isn’t typically part of his plan. In the future, he could reduce his reliance on special needs stations at unfamiliar race courses by carrying his gels from the start. This would help mitigate the psychological stress of last minute audibles.
PF&H

Leon's full stats

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Overall
830g total carb
124g per hour
7,670ml total fluid
1,143ml per hour
4,433mg total sodium
661mg per hour
578mg
Sodium per litre
559mg total caffeine
8.3mg per kg
Bike and Run
Bike
Run

Data Confidence
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We rate each of our case studies from 1-5 based on the level of accuracy, and our confidence in the data.
1
2
3
4
5

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.

Leon's recent case studies

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