Robbie's headline numbers
Robbie's strategy
Fueling
T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
T - 15mins: Took in a final dose of carb
"It was a psychological and not physiological factor that slowed me down"
Robbie planned to consume ~90g carb per hour during the event, and with the assistance of his crewing team, he was able to adapt his plan mid-race and eventually averaged ~97g per hour for the 24 hours. This is yet another example of an elite athlete who’s able to consume more than 90g of carb per hour after training his gut for a number of years. Robbie experienced a small dip in pace between hours 12-18 (between 10pm and 4am), but after analysing his fuel intake we concluded this was likely due to a psychological drop as it can be challenging to run through the night due to the darkness. Thankfully for Robbie, he managed to pick the pace back up and finished with a staggering 4 minute 3 second last kilometer!
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 important if he wants to perform at his best.
Learn moreT - 60mins: Drank ~500ml of strong electrolyte drink
"I had to pee a lot, although I only finished 500g lighter than when I started"
Overall, Robbie drank an average of ~377ml fluid per hour, with a relative sodium concentration of ~923 milligrams per litre (32oz), which are similar to his losses, predominantly through PF Carb & Electrolyte Drink Mix. Robbie peed a couple of times in the first few hours of the race, so he dialled his fluid intake back to account for the colder conditions during this period, before increasing his intake as the conditions got more humid (~90%). During the warmer parts of the day, Robbie also poured water over his head to keep cool. Robbie weighed himself before and after the race to estimate his total fluid losses, and as he only dropped ~0.5kg (17oz) across the entire race, it’s likely that he was hydrating appropriately. We know from the scientific research 100% of fluid losses don’t need replacing ,and aiming for a weight loss of <2% is important in limiting the potential for performance decreases occurring.
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.
Consuming caffeine in the hours before the start may have increased perceived energy levels
During events lasting as long as 24 hours, it’s extremely common to see athletes exceed the general recommendations. Whilst Robbie’s overall intake was slightly above this the four-to-five hour half-life of caffeine likely meant the amount circulating in his blood at any given time, was appropriate for an event of this duration. In future races, Robbie could look to increase his overall caffeine intake and concentrate a higher intake during hours 12-18 as this is where his pace dipped. Consuming a higher dose of caffeine has been shown to lower perceived effort and increase alertness, potentially helping to combat his psychological drop off during this time.
How Robbie hit his numbers
Here's everything that Robbie ate and drank on the day...
Final thoughts
“I'm so happy to have broken the 24 hour British record which has stood for 41 years! However, there is always room for improvement. I know what I can do to go even further next time!”
“After a bout of COVID-19 forced Robbie to pull out of his previous British 24-hour record breaking attempt in 2022, he was thrilled to break a record. Robbie was extremely pleased with how he pulled on what we call ‘the three levers’ for fueling endurance performance (namely carb, sodium and fluid), but he was keen to praise his support crew who helped ensure he stayed fueled, hydrated and on pace. ”
PF&HRobbie's full stats
Data Confidence
We rate each of our case studies from 1-5 based on the level of accuracy, and our confidence in the data.
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).