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Gregory Barnaby

Gregory Barnaby

Singapore T100

6th April, 2025SingaporeMarina Bay5th, MPRO

Gregory's headline numbers

~111g
Carb per hour
Recommended 90g/h+
~1,600ml
Fluid per hour
Recommended 1,500-2,000ml/h
~513mg
Sodium per litre
Recommended 800-1200mg/L
~4.3mg
Caffeine per kg
Recommended 3-6mg/kg
Image Credits: @t100triathlon

Gregory'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)

Didn't pre-fuel

Gregory would benefit from taking in a final dose of carb <30 minutes before

Carb per hour
Recommended 90g/h+
~111g
Gregory's Energy Rating9/10

"Despite losing a key bottle of carbs and sodium, everything went well. I had a contingency plan and felt I stayed well-fueled."

Our thoughts

Following his IRONMAN® Pro Series victory in 2024, Gregory shifted his focus to target the T100 series. Gregory hasn’t struggled to tolerate higher rates of carbohydrate intake even as conditions become more stressful (hotter/more humid), so he planned to consume ~120g/h in an attempt to account for the increased glycogen utilization observed as body temperatures rise, falling just short of that at ~111g/h. He originally brought two 1L bottles with 1 x PH 1500 (Tablet) and 120g of PF Carb Only Drink Mix in each, but on the bumpy roads of Singapore, one bottle escaped. Showing his experience, Gregory had a backup plan with additional PF 30 Gels and Electrolyte Capsules on the bike, alongside the on-course energy drink mix, which he knew he could handle, given he had practised with it over the years. He also reported feeling like he needed something extra on the run and subsequently picked up more gels than planned to increase his carb intake. It resulted in a higher intake on the run compared to the bike, which is something we don’t see too often. However, since he didn’t report any GI disturbance, this high intake in the hot and humid conditions helped to support his performance right through to the finish where some competitors appeared to fade.

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.

Pre-loaded electrolytes

T - 60mins: Drank ~500ml of strong electrolyte drink

Fluid per hour
Recommended 1,500-2,000ml/h
~1,600ml
Sodium per litre
Recommended 800-1200mg/L
~513mg
Gregory's Hydration Rating8/10

"I was so proactive with my hydration in this race and executed the plan, so I felt like all went well."

Our thoughts

Heading into such a challenging first race of the season, Gregory took advantage of the PF&H Sports Science team upon recently joining the athlete roster and utilised their support to determine how much fluid he needed to carry for the race. After learning that he would need >1.7L/h on the bike and run to maintain a level of dehydration below 4%, in line with the scientific guidelines, Gregory wisely aimed above this and hit ~1.8L/h on the bike and ~1.6L/h on the run. He managed one of the highest fluid intakes we’ve recorded in our Case Study database, second to only an athlete racing at the IRONMAN® World Championships in Kona 2024. Despite such a high intake, with the extreme conditions, he was likely more than 2% dehydrated at the finish line. For a race of this relatively shorter duration, being somewhere between 2 and 4% dehydrated at the finish line likely supported his hydration status enough to minimise any negative impact. Had Gregory not lost one of his starting bottles early on, he may have even had a higher intake. To help keep cool, he grabbed bottles of plain water from aid stations on the bike and water cups every 2km on the run, and along with drinking from both bottles and cups, he doused water himself with plain water as frequently as possible to improve his performance under exercise heat stress.

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
~4.3mg
Our thoughts

As an additional lever for endurance exercise performance (after carbs, fluid and sodium), caffeine was part of Gregory’s strategy, with a total of three PF 30 Caffeine Gels across the race; one on the bike, and two on the run. Although he reached the right total dose, in future races, he’s going to bring forward his final caffeine dose to better account for the time it takes for caffeine to be absorbed into the bloodstream (~45-60 minutes) so he can feel the performance enhancing effects earlier on in the race.

How Gregory hit his numbers

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

Before race (>30 mins)
Pre-race (<30 mins)
  • 200ml x Plain water
Bike
Run

Final thoughts

Gregory's Satisfaction Rating8/10

I felt it was a good performance and a great way to start the season but there’s always room for improvement.

Gregory

Gregory started the season with a strong performance in Singapore, especially for a self-confessed long-distance specialist. It’s likely that the warm conditions played to his advantage, given his ability to tolerate a high rate of carbohydrate and fluid intake required to sustain exercise performance in such hot and humid conditions. His backup planning served him well and fueled him to the finish line, ensuring he had some emergency carbs and sodium to help him through any misadventures on the tricky bike course.

PF&H

Gregory's full stats

Overall
376g total carb111g per hour
5,400ml total fluid1,600ml per hour
2,769mg total sodium820mg per hour
513mgSodium per litre
300mg total caffeine4.3mg per kg
Bike and Run
Bike
Run

Data Confidence

We rate each of our case studies from 1-5 based on the level of accuracy, and our confidence in the data.

12345

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.

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