Nick Harris-Fry
London Marathon
Nick's headline numbers
Nick'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.
Nick pre-fueled sufficiently with a carb-rich breakfast and some energy drink right before the race to top up his energy stores and kickstart his blood sugar. Despite consuming some energy gels and drinks during the race itself, Nick averaged ~50g/h of carbohydrate, which is lower than the scientific recommendations for a race of this distance and intensity. This is largely due to the fact that he experienced some GI discomfort and consequently had to limit his fueling until his stomach settled. Ahead of future races, we would recommend Nick undergo structured gut training during his longer and higher intensity sessions to ensure he can comfortably tolerate higher volumes of carbohydrate to maintain his energy levels.
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.
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 Nick’s losses are on the low side, getting his hydration strategy right is still important if he wants to perform at his best.
Learn moreGiven the mild temperatures, it's likely that the ~353ml/h of fluid Nick consumed was sufficient to stay on top of his losses and avoid dehydration. He picked up cups of water from the aid stations to avoid having to carry any fluid himself, and took a couple of Electrolyte Capsules. Although Nick’s relative sodium intake was fairly close to his losses based on the Sweat Test results, he still experienced some twinges of cramp towards the end of the race. This may mean his fluid replacement was less than his actual sweat losses even in the mild temperatures. It’s worth noting that muscle fatigue accumulated throughout the race may also have caused these twinges, as cramp is multifactorial.. It’s worth noting that muscle fatigue accumulated throughout the race may also have caused these twinges, as cramp is multifactorial.
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.
Nick consumed one caffeinated gel during the race, delivering a relatively small dose of caffeine, but since he had some coffee with his breakfast, it’s likely the stimulant was still in his system by the time the race began. To fully reap the ergogenic benefits of caffeine in future marathons, he could add a larger dose during to top-up, and fall more in line with the scientific recommendations. This would hopefully help Nick maintain his energy levels, and reduce the perception of effort later on.
How Nick hit his numbers
Here's everything that Nick ate and drank on the day...
Nick's weapons of choice
Final thoughts
PF&HNick's full stats
Data Confidence?
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.