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Sam Appleton

Pro

IRONMAN 70.3® Boulder

14th June, 2025
USA
Boulder, Colorado
1st, MPRO
Triathlon, Middle distance - 113.1km
25°C
, Hot
3hrs 35mins
more race details

Sam's headline numbers

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?
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~87
g
Carb per hour
Recommended 90g/h+
~821
ml
Fluid per hour
Recommended 500-1,000ml/h
~456
mg
Sodium per litre
Recommended 500-900mg/L
~3.5
mg
Caffeine per kg
Recommended 3-6mg/kg

Sam'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
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T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
pre-fueled
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T - 15mins: Took in a final dose of carb
Carb per hour
Recommended 90g/h+
~87
g
Sam's Energy Rating
8
/10
"I had good steady energy all day, no crashing or bonking."
Our thoughts

Sam made some small but smart refinements to his pre-race fueling ahead of an early start at IRONMAN 70.3® Boulder, including adding a few more carbs to his usual ‘light’ race day meal. The key difference to his strategy came on the bike, as he hit over 120g of carbs per hour, his highest ever 70.3® bike intake. Sam used a mix that he’d practiced with: PF Carb Only Drink Mix, alongside either a PF 30 Gel or PF 30 Caffeine Gel every 20 minutes to drip feed his fuel and avoid the dips in energy levels he has previously experienced whilst racing. Although he topped up with just enough fuel on the run to keep his momentum going and hold off fellow PF&H ambassador Colin Szuch, we would recommend a higher intake than ~38g/h over the 1 hour 15 minute run to better support his energy levels and performance next time out. This could be achieved by grabbing a couple of PF 30 Gels in T2 as he heads out on to the run course.

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.

Sam655mg/L
Sam 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.

Whilst Sam’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 more
Didn't pre-load electrolytes
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Drinking a strong electrolyte drink before the race could have helped Sam start optimally hydrated
Fluid per hour
Recommended 500-1,000ml/h
~821
ml
Sodium per litre
Recommended 500-900mg/L
~456
mg
Sam's Hydration Rating
7
/10
"I didn’t consume as much as I wanted because my bottles were deemed non-compliant."
Our thoughts

As an experienced racer with a low sweat sodium concentration, Sam handled his sodium and fluid intake well even when the temperature in Boulder (and therefore his sweat rate) started to rise. Despite having to change his planned bottles to smaller ones ahead of the start, he was able to drink close to one litre (~32oz) per hour on the bike before dropping to ~800ml/h on the run from a soft flask and aid station cups of water and coke. Similarly to his improved fueling, this fluid intake was close to double that of his 2021 IRONMAN 70.3® Boulder strategy, showing a more proactive fluid replacement strategy to maintain performance as temperatures increased.

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.

Didn't pre-load caffeine
?
Consuming caffeine in the hours before the start may have increased perceived energy levels
Caffeine per kg
Recommended 3-6mg/kg
~3.5
mg
Our thoughts

Consistent with his previous races, Sam incorporated two PF 30 Caffeine Gels into his race-day fueling strategy. This pushed his total caffeine intake above the 3mg/kg minimum dose recommended to experience the stimulant’s well-documented ergogenic effects - particularly useful in the latter stages of the race when the mental and physical fatigue increased and his carb intake dropped.

How Sam hit his numbers

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

Sam's weapons of choice

Final thoughts

Sam's Satisfaction Rating
9
/10
This one's for the old dogs. On the fuel and hydration side, I executed the strategy well!
Sam
As a long-time PF&H ambassador, Sam’s continual evolution of his fuel and hydration strategy was on display in Boulder, showcasing a 38% increase in carbs from the same race in 2021. A frontload of carbs, fluid and sodium on the bike was enough to hold off the chasers on the run and power him to the win.
PF&H

Sam's full stats

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Overall
313g total carb
87g per hour
2,955ml total fluid
821ml per hour
1,346mg total sodium
374mg per hour
456mg
Sodium per litre
229mg total caffeine
3.5mg 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 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.

Sam's recent case studies

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