Bre Mirynech
Fat Dog 100km
Bre's headline numbers
Bre'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.
Bre had a target of 75g of carb per hour, inline with the recommendations for events of this duration and intensity. Her routine intake of one PF 30 Gel every 30 minutes as well as half a PF 30 Chew on the hour allowed her to reach her target for the first 7 hours. After this point, Bre transitioned to just PF 30 Gels and PF 30 Caffeine Gels supplemented with real food, including noodles and potatoes, to prevent flavour fatigue - a common challenge in ultra events and something she’d previously experienced. Bre’s real food choices were deliberately high in carbohydrates and sodium but low in fat and fibre to maintain her energy availability without compromising her gut comfort. Her clear, well-rehearsed fueling strategy ensured she achieved her carbohydrate requirements impressively consistently over the 100km race.
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.
Given Bre’s losses are High (1,392mg/L), nailing her hydration strategy becomes especially crucial when it’s hot and/or humid.
Learn moreBre made a conscious and planned effort to stay on top of her hydration over the ~21 hours of running, especially as the temperature rose to 29℃ (~84℉) in the afternoon. Her proactive approach helped her avoid any symptoms of excessive dehydration such as cramps, nausea and a decline in performance. Bre made sure to drink at least one bottle of PH 1500 (Tablets) for every bottle of plain water she had, and also boosted her relative sodium concentration using a dose of 100mg of electrolyte capsules every hour. Replacing a good proportion of her high sweat sodium concentration meant that Bre was able to feel strong throughout the 100km.
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.
Bre had her first PF 30 Caffeine Gel 2 hours into the race, and then topped up with a dose roughly every 4 hours thereafter to maintain a level of caffeine in her bloodstream that maximised the ergogenic effects. In doing so, she slightly exceeded the overall 6mg/kg recommended dosage; however, this is common in ultras of this duration as the recommendations are primarily based on events under 12 hours. In future, Bre could trial a new strategy, which would involve delaying her first caffeine intake until night when the body’s circadian rhythm is promoting sleep. This may better support her mental alertness through the night when she experienced reduced energy and the effects of limited sleep.
How Bre hit her numbers
Here's everything that Bre ate and drank on the day...
Bre's weapons of choice
Final thoughts
Bre
PF&HBre'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.