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Alex Leprêtre

London Marathon

23rd April, 2023
England
London
3rd
Running, Marathon - 42.2km
13°C
, Mild
2hrs 15mins
more race details

Alex's headline numbers

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?
?
~67
g
Carb per hour
Recommended 75g/h
~111
ml
Fluid per hour
Recommended 0-500ml/h
0
mg
Sodium per litre
Recommended 600-1000mg/L
0
mg
Total caffeine

Alex'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 75g/h
~67
g
Alex's Energy Rating
8
/10
"My energy was really good, I struggled a bit towards the end but wouldn't put this down to fueling."
Our thoughts

As someone who’s always specialised in shorter distances, this was the first time Alex ever has had to eat or drink during a race. In the days leading up to his debut marathon, he followed the advice of the PF&H Sports Scientists to a T and carb loaded, even including a ‘pasta party’ the night before. He fully embraced the need for additional carb during longer events while burning so much energy (averaging 3:16 mins per km) and so incorporated gut training into his marathon-specific sessions to make this as comfortable as possible on race day. His strategy was relatively simple: a PF 30 Gel every 25 minutes. He was due to have another gel during this race but felt full so didn't manage to get another in. However, if Alex had, he would have been closer to the recommended intake and felt more energised going into the back end of the run. Alex rated his overall energy levels as an 8 (out of 10) with a bit of a lull towards the end of the race, but certainly no ‘wall’ or ‘bonk’ in sight.

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.

Alex860mg/L
Alex 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 Alex’s losses are on the moderate side, getting his hydration strategy right is still important if he wants to perform at his best.

Learn more
Pre-loaded electrolytes
?
T - 60mins: Drank ~500ml of strong electrolyte drink
Fluid per hour
Recommended 0-500ml/h
~111
ml
Sodium per litre
Recommended 600-1000mg/L
0
mg
Alex's Hydration Rating
7
/10
"I clearly didn't take in much water, but also didn't feel thirsty or dehydrated on such a mild, rainy day."
Our thoughts

Since going into endurance events dehydrated is actually a common performance-limiting issue for athletes, Alex preloaded with a PH 1500 both the night before and morning of the marathon, ensuring optimal hydration levels at the race start. With this proactive approach combined with the mild (13°C / 55°F) and rainy weather, it wasn’t surprising to hear that Alex never felt particularly thirsty throughout the race. While he only drank ~250ml of plain water across the two and a quarter hours, we would still recommend including some sodium in his plan. One of the main reasons for this is the key role that sodium plays in assisting with carbohydrate absorption, via ‘glucose sodium cotransporters’.

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
Total caffeine
0
mg
Our thoughts

Alex could try optimising his future intake by making the most of caffeine and its performance associated benefits. His two coffees in the morning would have contributed somewhat to boost his perceived energy levels, especially with the morning race start time, but taking it a step further by swapping one or two of his regular gels for a PF 30 Caffeine Gel may have helped reduce his perceived exertion and increase focus.

How Alex hit his numbers

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

Alex's weapons of choice

Final thoughts

Alex's Satisfaction Rating
7
/10
I am satisfied with this result, but think if all goes well I can run 2-3 minutes quicker in Berlin.
Alex
As this was the first time Alex has ever had to think about fueling or hydrating during a race, he worked with the PF&H Sports Science team in advance to prepare his strategy. Amazingly, despite his impressive running pedigree, Alex didn’t secure an elite start position, meaning he began the race with the 40,000 non-elite starters, of which only two beat him on the day. This meant Alex barely saw another runner for the 42.2km, and wasn’t able to run in a pack like the pros. Looking forward, he can further refine his race strategy for Berlin by optimising electrolyte intake, caffeine and gut training so he is comfortable tolerating additional carb despite this Alex finished with a strong 2:15:01 in his debut marathon.
PF&H

Alex's full stats

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?
?
Overall
150g total carb
67g per hour
250ml total fluid
111ml per hour
0mg total sodium
0mg per hour
0mg
Sodium per litre

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.

Alex's recent case studies

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