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Marc Dubrick

Pro

IRONMAN 70.3® World Championships

26th August, 2023
Finland
Lahti
8th, MPRO
Triathlon, Middle distance - 113.1km
16°C
, Mild
3hrs 38mins
more race details

Marc's headline numbers

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~115
g
Carb per hour
Recommended 90g/h+
~672
ml
Fluid per hour
Recommended 250-750ml/h
~1,246
mg
Sodium per litre
Recommended 900-1300mg/L
~3.3
mg
Caffeine per kg
Recommended 3-6mg/kg

Marc'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+
~115
g
Our thoughts

For an event of this length and intensity, it was vital that Marc hit a high carbohydrate intake throughout whilst keeping his stomach comfortable. He front-loaded his fuel on the bike slightly with ~115g/h before taking a little less ~107g/h on the run. Although he experienced some stomach pain between miles 4-8 (6-12km) on the run, Marc was able to relax enough that the pain subsided. In future, Marc may want to increase the number of race-intensity, high-fueling training sessions in an attempt to ‘train his gut’ to tolerate this high carb intake more comfortably.

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.

Marc1146mg/L
Marc 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 Marc’s losses are High (1,146mg/L), nailing his hydration strategy remains important, even when it’s Mild.

Learn more
Pre-loaded electrolytes
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T - 60mins: Drank ~500ml of strong electrolyte drink
Fluid per hour
Recommended 250-750ml/h
~672
ml
Sodium per litre
Recommended 900-1300mg/L
~1,246
mg
Marc's Hydration Rating
9
/10
" I didn't get any muscle cramping and was able to pee on the bike, so I felt like my hydration was good enough"
Our thoughts

With cool conditions in Finland (~16℃ / 60ºF) and with Marc’s moderate sweat rate, he replaced his sweat losses adequately throughout the race. As most of his fluid intake was made up of PF Carb & Electrolyte Drink Mix, his average relative sodium concentration of his intake was ~1,341mg/L. This is similar to his sweat sodium concentration (1,146mg/L) so would likely have replaced a high proportion of his sweat electrolyte losses.

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
~3.3
mg
Our thoughts

Marc took a PF 30 Caffeine Gel on both the bike and the run, which meant his total intake was just below the scientific recommendations for endurance sports. He will likely have received some solid perceptual benefits from this, but may wish to consider swapping his pre-race gel for a PF 30 Caffeine Gel to maximise the benefits of the stimulant.

How Marc hit his numbers

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

Marc's weapons of choice

Final thoughts

Marc's Satisfaction Rating
9
/10
Had an all-time best 70.3 record!
Marc
Marc pushed to his limits to achieve an amazing 8th place in the World. With a solid fuel and hydration strategy with tactical caffeine use Marc was able to push out an all time best bike power which helped him rate his race satisfaction 9 (out of 10).
PF&H

Marc's full stats

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Overall
419g total carb
115g per hour
2,446ml total fluid
672ml per hour
3,049mg total sodium
837mg per hour
1,246mg
Sodium per litre
240mg total caffeine
3.3mg 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.
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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.

Marc's recent case studies

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