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Marc Dubrick

Pro

IM 70.3 Indian Wells

3rd December, 2023
USA
California
2nd, MPRO
Triathlon, Middle distance - 113km
15°C
, Mild
3hrs 40mins
more race details

Marc's headline numbers

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?
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~111
g
Carb per hour
Recommended 90g/h+
~588
ml
Fluid per hour
Recommended 500-1,000ml/h
~1,020
mg
Sodium per litre
Recommended 900-1300mg/L
~2.9
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+
~111
g
Marc's Energy Rating
9
/10
" I nailed my fueling and that enabled me to finish strongly; I went from 4th to 2nd and made up 50 seconds in the last 3km."
Our thoughts

Similarly to his IRONMAN 70.3 World Championships, Marc consumed more than 100g of carb per hour to fuel a strong finish. Despite the early race start time, Marc always plans to get a carb-rich breakfast in ~3 hours before the swim to ensure he’s starting well fueled. Marc focuses on being self-sufficient with his fuel on the bike by carrying one-third of a Flow Gel and PF Carb and Electrolyte Drink Mix in his various bottles. He also prefers not to rely on aid stations on the run, and switches to a 250ml soft flask containing maple syrup - one of Marc’s favourite carb sources - along with a PH 1500 packet to add a final 15g carb, topping off his high fueling intake throughout the speedy half marathon. This solid carb intake saw Marc plough through the run course to take second place.

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
?
T - 60mins: Drank ~500ml of strong electrolyte drink
Fluid per hour
Recommended 500-1,000ml/h
~588
ml
Sodium per litre
Recommended 900-1300mg/L
~1,020
mg
Marc's Hydration Rating
10
/10
"I probably wouldn't change anything about my strategy. I was happy with how I felt towards the end of the race."
Our thoughts

In the mild race conditions, Marc implemented his hydration strategy effectively to replace a good proportion of his sweat losses. This involved using PF Carb & Electrolyte Drink Mix on the bike and concentrated PH 1500 on the run to take on a relative sodium concentration similar to that of his sweat sodium losses. On the bike, Marc had two further bottles with him, which he chose not to drink as he didn’t feel he needed to and he had a few additional sips of caffeinated energy drinks on the run. This worked well for Marc in these conditions, but we would recommend he collects some sweat rate data going forward to help refine his fluid strategy, especially going into hotter races where he’s admitted that he’s struggled to produce his best in the past.

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
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Consuming caffeine in the hours before the start may have increased perceived energy levels
Caffeine per kg
Recommended 3-6mg/kg
~2.9
mg
Our thoughts

Marc has experimented with caffeine to perfect the timing of the stimulant's use on race day, in an attempt to maximise its ergogenic effects. He takes one PF 30 Caffeine Gel an hour into the bike, and then another 5 miles into the run. Given caffeine takes ~45-60 minutes to peak in the bloodstream, Marc’s strategy ensures he will enjoy a boost in his energy levels towards the back end of each of the bike and run legs. To reach what the research suggests is the optimal caffeine dose for endurance exercise, Marc may look to add one more caffeine gel to his race day strategy ~15 minutes before the start to sit within the recommended ranges.

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
This was my first time going into back-to-back 70.3 races and I felt good. My legs felt great the whole day, the weather was perfect, and the only reason I wouldn’t rate my satisfaction a 10 is because I didn’t win.
Marc
As we’ve seen him do previously, Marc tolerated an impressive amount of carb during a great race in California. He could look to further refine his fluid and caffeine intake for future races to optimise performance benefits and avoid any detriments of disproportionate fluid replacement.
PF&H

Marc's full stats

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Overall
408g total carb
111g per hour
2,160ml total fluid
588ml per hour
2,202mg total sodium
600mg per hour
1,020mg
Sodium per litre
206mg total caffeine
2.9mg 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.

Marc's recent case studies

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