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Robbie Britton

Pro

Leadville 100 Run

17th August, 2024
USA
Leadville
6th, MPRO
strava
Running, Ultra - 161km
20°C
, Hot
17hrs 56mins
more race details

Robbie's headline numbers

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~84
g
Carb per hour
Recommended 90g/h+
~513
ml
Fluid per hour
Recommended 500-1,000ml/h
~802
mg
Sodium per litre
Recommended 800-1200mg/L
~3.2
mg
Caffeine per kg
Recommended 3-6mg/kg
Image Credits: @precisionfandh

Robbie'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+
~84
g
Robbie's Energy Rating
7
/10
"I aimed for around 100 grams of carb per hour, and I think I hit this for a decent amount of the race. I got quite bloated in the second half so I backed off the carbs for a bit but still managed to keep myself moving pretty well."
Our thoughts

Experienced ultra-runner, Robbie, has tried and tested his fueling plan numerous times, but it was put to the test in extreme conditions in Leadville as the course began at an altitude of ~10,200ft (3,000m), and climbed ~12,000ft (3,600m) throughout the 100 miles (161km). PF&H Sports Scientist, Minty, was tracking Robbie’s intake closely throughout the race as he crewed him, and saw his average intake stable at ~110g/h for the first nine hours, showing his prior gut training clearly paying off. From there on, however, Robbie decided to ‘decouple’ his carb and fluid intake to alleviate some unexpected and intense stomach discomfort. This took a long time, and his carb intake fell significantly in the final hours of the race. He still averaged within the recommended amount for a race of this nature, but we’ll likely see him average ~100g/h in future 100 milers as he’s done previously en route to the British 24-hour record in Italy in 2023.

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.

Robbie1044mg/L
Robbie 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 Robbie’s losses are on the moderate 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
Pre-loaded electrolytes
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T - 60mins: Drank ~500ml of strong electrolyte drink
Fluid per hour
Recommended 500-1,000ml/h
~513
ml
Sodium per litre
Recommended 800-1200mg/L
~802
mg
Robbie's Hydration Rating
9
/10
"I was sweating quite a lot, but I never felt too thirsty. I ran out of drinks a couple of times so it must have been hot, but I never felt dehydrated."
Our thoughts

Robbie got the majority of his electrolyte intake from PF Carb & Electrolyte Drink Mix, which comes with a very similar concentration of sodium to his sweat. This worked very well until he began to ‘decouple’ his carb and fluid intake, and whilst some of his bottles then contained PH 1000 (Drink Mix), he also drank ~2L of plain water to reduce his stomach discomfort, which dropped his average concentration slightly. Robbie kept a lid on his core temperature by picking up ice from every crewed aid station and paced the event very well to avoid overheating or overexerting himself at any point.

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
~3.2
mg
Our thoughts

Robbie took a decent dose of caffeine pre-race, introducing ~180mg into his bloodstream before toeing the start line. He then topped up his circulating levels in the second half of the race to ensure he was always reaping the associated ergogenic benefits. Robbie’s mid-race dose fell just within the scientifically recommended amount, but he would likely have taken some more in the final hours if he wasn’t experiencing any GI discomfort.

How Robbie hit his numbers

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

Robbie's weapons of choice

Final thoughts

Robbie's Satisfaction Rating
7
/10
I’m pleased with my first crack at Leadville, I had to adjust my plan on the fly but managed to get enough carb, fluid and sodium in to get me through to the finish line.
Robbie
Robbie’s debut at the infamous Leadville 100 was as brutal as he expected, with the topography, altitude and temperatures all playing significant roles. He listened to his body and adapted his nutrition strategy mid-race to reduce liquid carbs and overall carb intake to limit the discomfort he was experiencing. Robbie put this discomfort down to some prior stomach upset before the race, although the altitude and high temperatures at points may have added to this distress.
PF&H

Robbie's full stats

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Overall
1516g total carb
84g per hour
9,200ml total fluid
513ml per hour
7,375mg total sodium
411mg per hour
802mg
Sodium per litre
200mg total caffeine
3.2mg per kg

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 good confidence in the accuracy of the data reported. An athlete feels that the numbers closely reflect what they consumed despite a couple of estimations which may carry some degree of error. The majority of what was consumed is recorded to a high level of specificity (most volumes are known through the use of bottles brands quantities flavours). The numbers are very plausible and align with previous data recordings (if an athlete has collected data previously).

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