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Steph Clutterbuck

Steph Clutterbuck

IRONMAN 70.3® World Championships

26th August, 2023FinlandLahti1st, F25-29strava

Steph's headline numbers

~108g
Carb per hour
Recommended 90g/h+
~708ml
Fluid per hour
Recommended 500-1,000ml/h
~1,667mg
Sodium per litre
Recommended 800-1200mg/L
~3.1mg
Caffeine per kg
Recommended 3-6mg/kg

Steph'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-rich meal

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+
~108g
Steph's Energy Rating7/10

"My energy levels felt lower than normal on race day, but did pick up throughout the race - I felt a little flat but I definitely got stronger as the run went on"

Our thoughts

Steph has spent several months training her gut to tolerate such high carb intakes so she can train and recover optimally. Despite feeling like her energy levels were below par, she rated her GI comfort a solid 10 (out of 10) showing how effective this practice has been. Although her perception of ‘feeling a little flat’ in the early stages, averaging ~108g per hour set her up for a strong finish

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.

Steph1106mg/L

Steph has been Sweat Tested to dial in her 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 Steph's losses are High (1,106mg/L), nailing her hydration strategy remains important, even when it's Mild.

Learn more
Pre-loaded electrolytes

T - 60mins: Drank ~500ml of strong electrolyte drink

Fluid per hour
Recommended 500-1,000ml/h
~708ml
Sodium per litre
Recommended 800-1200mg/L
~1,667mg
Steph's Hydration Rating9/10

"I felt well hydrated and was able to manage my body temperature very well, even when the sun came out on the run I still didn't overheat - much better management than my last 70.3"

Our thoughts

Steph’s previous IM 70.3 was in Staffordshire where she accidentally diluted her electrolyte concentration too much on the run by drinking lots of water. This time in Lahti she managed her electrolytes perfectly on the bike, but over-concentrated on the run by having a double-strength Soft Flask of PH 1500 and six Electrolyte Capsules, without drinking much water. In future she could consider reducing the amount of Electrolyte Capsules slightly, to achieve a concentration closer to her sweat sodium of 1,107mg/L, as determined by a Sweat Test.

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

T - 0-4hrs: Had a final hit of caffeine

Caffeine per kg
Recommended 3-6mg/kg
~3.1mg
Our thoughts

Steph has found great benefit from regularly taking caffeine during her races, and falling within the 3-6mg/kg recommended dosage will certainly have helped her reap the associated benefits

How Steph hit her numbers

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

Before race (>30 mins)
Pre-race (<30 mins)
Bike

Final thoughts

Steph's Satisfaction Rating8/10

I'm VERY pleased with a World Champs AG win!! However I definitely had more to give on the day.

Steph

Steph executed a solid race to claim her first age group world title over the 70.3 distance. To help optimise her intake slightly, she may want to consider reducing the sodium concentration of her drinks during the run by reducing the number of Electrolyte Capsules or increasing the amount of plain water she picks up. As her next race will be at the full distance IRONMAN® World Champs in Kona, Hawaii, where temperatures will likely be much higher, nailing the concentration and amount of fluid she drinks will be essential to stay on top of her sweat losses and avoid the negative performance effects of dehydration and electrolyte depletion.

PF&H

Steph's full stats

Overall
482g total carb108g per hour
3,150ml total fluid708ml per hour
5,250mg total sodium1,180mg per hour
1,667mgSodium per litre
200mg total caffeine3.1mg per kg
Bike and Run
Bike
Run

Data Confidence

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

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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.

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