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Tara Grosvenor

Pro

Trail 100 Andorra by UTMB

24th June, 2023
Andorra
Ordino
Top 100
Running, Ultra - 105km
27°C
, Very Hot
20hrs 41mins
more race details

Tara's headline numbers

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?
?
~54
g
Carb per hour
Recommended 75g/h
~711
ml
Fluid per hour
Recommended 500-1,000ml/h
~534
mg
Sodium per litre
Recommended 500-900mg/L
~6.2
mg
Caffeine per kg
Recommended 3-6mg/kg

Tara'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
?
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
~54
g
Tara's Energy Rating
8
/10
"I felt like I fueled quite well, but I still think I could’ve done better. I’ll probably switch to more sports nutrition to get more fuel in future. "
Our thoughts

Tara used a mixture of her own sports nutrition products, incorporating some PF 30 Gels, PF 30 Caffeine Gels, and PF 30 Chews and picked up a variety of sweets and other ‘real food’ carb sources from aid stations along the way. This strategy is common during this style of hilly ultramarathon where carrying extra weight is traded off against having readily available fuel. Tara also stopped to eat a bowl of rice and had a few cups of cola. She did feel that she could’ve spent longer at the aid stations in the middle of the day, to try and get her head out of ‘race mentality’ and focus on the fact that she needed to eat and prepare for the hours ahead. Towards the end of the race, Tara slightly made up for this with some salty chicken broth, which she had been craving for hours, potentially suggesting that her sodium levels were low as her body was craving salty foods.

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.

Tara716mg/L
Tara has been Sweat Tested to dial in her 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 Tara’s losses are on the low side, getting her hydration strategy right is still crucial when it’s hot and/or humid as her 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
~711
ml
Sodium per litre
Recommended 500-900mg/L
~534
mg
Tara's Hydration Rating
6
/10
"I don’t think I drank enough water throughout the day and I felt dizzy a few times when lacking salt. This was because I got a bit lazy in the middle of the day, not spending enough time at aid stations because I was in a race mentality and just grabbed what I needed."
Our thoughts

With large fluctuations in temperature during this race, Tara mentioned feeling shifts in how thirsty she was, likely exacerbated by being at altitude for large portions of the race. With a relatively high fluid intake of ~700ml per hour across the 20-hour race, it’s likely that she over-hydrated at times when the conditions changed around her. Tara needed to pee frequently during the race, a typical symptom of over-drinking. It’s possible that despite her lower-than-average sweat sodium losses, the large volume of sweat she loses, alongside the equally large amount of plain water she consumed, contributed to this. This is because her body simply wasn’t able to retain much without appropriate amounts of sodium, so in future races she may look to replace some of this plain water with PH 1000.

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
~6.2
mg
Our thoughts

Tara sat just above the recommended caffeine intake to induce ergogenic benefits during endurance exercise. However, these recommendations don’t account for the extended duration of ultramarathons such as this, so taking in slightly more caffeine could be of further benefit. Tara did this whilst experiencing no negative side effects, so although the rating is amber, we wouldn’t recommend she change anything.

How Tara hit her numbers

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

Tara's weapons of choice

Final thoughts

Tara's Satisfaction Rating
6
/10
For my first ultramarathon, I’m really happy that I didn’t have any major issues nutritionally. Furthermore, I think I underestimated my high sweat rate, and the effect altitude has on this. I’m looking forward to my next race at the 2023 UTMB festival, where I’ll race the CCC and look to optimise my strategy.
Tara
Tara pushed herself to new limits by undertaking a race more than double the duration of her previous longest run. This came with fueling and hydration challenges and changes which Tara generally adjusted to well. She may want to adapt her hydration strategy for future races to prevent needing to pee so frequently, balancing her fluid intake with her sodium replacements to more closely match her total sweat losses, and her sweat sodium concentration.
PF&H

Tara's full stats

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?
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Overall
1110g total carb
54g per hour
14,703ml total fluid
711ml per hour
7,853mg total sodium
380mg per hour
534mg
Sodium per litre
373mg total caffeine
6.2mg 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.
1
2
3
4
5

There is some confidence in the quantities and brands of products consumed but the data may lack specifics (e.g. volumes specific flavours). A high number of estimations have been made and the room for error is moderate-high. There may also be the possibility that some intake has been grossly over- or under-estimated.

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