Francois de Repentigny
Boston Marathon
Francois' headline numbers
Francois' strategy
Fueling
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
After a 20 minute call with a member from our Sports Science team, Francois felt well-prepared to race the Boston Marathon. Unfortunately an injury meant his original predicted finish wasn’t on the cards this time around. He still managed to fuel consistently throughout, consuming five PF 30 Gels along with a few caffeinated energy gels to reach a carb intake of ~51 grams per hour. This intake falls slightly below the general recommendations for a race of this duration and intensity. Although Francois rated his GI comfort as ten out of ten, it would be beneficial to perform some structured gut training, particularly when aiming for higher carb intakes, to ensure he has no issues whilst doing this at race-pace.
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 Francois’s losses are on the moderate side, getting his hydration strategy right is still crucial when it’s hot and/or humid as his higher sweat rate in these conditions can result in significant net losses over the duration of a race.
Learn moreFrancois' relative sodium intake almost directly matched his sweat sodium concentration of 1024mg/L. Combined with the temperate conditions on race day, it’s likely that the cramps he experienced towards the latter part of the race was not due to his sodium intake, but more a combination of injury and neuromuscular fatigue. Francois’ fluid intake during the marathon was suitable for the conditions and race itself, but moving forward, we would recommend him to do some sweat rate testing to get a more precise indication of his fluid losses during exercise to precisely dial in his fluid intake. A higher sweat rate would suggest he could have mis-matched his fluid intake to his sweat losses during this race, contributing to the colour of his pee and perhaps influence the cramping he experienced.
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.
Francois’ caffeine intake fell slightly below the scientific recommendations for performance benefits during a race of this distance and intensity. While he regularly drinks coffee and is accustomed to using the stimulant, we would suggest he trials using an increased dose during his training sessions to see how he responds to hopefully reap more of the ergogenic benefits.
How Francois hit his numbers
Here's everything that Francois ate and drank on the day...
Francois' weapons of choice
Final thoughts
Francois' 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.