IM 70.3 Los Cabos
Jason's headline numbers
Carbohydrate is the main fuel you burn when racing. Failing to fuel properly is a leading cause of underperformance in longer races.
This was only the second IM 70.3-distance race that we’ve crunched Jason’s numbers for, and he’s previously mentioned struggling towards the end of the run in this format, compared to the PTO 100k distance which is typically ~30 minutes shorter. To combat this, Jason maintained the same carb intake from his previous 100k races over this slightly longer format in Los Cabos, and his subjective feedback suggests this helped him maintain energy levels to the finish. Despite dropping his planned PF 30 Gel during the run, Jason made sure he collected a couple of on-course gels to still hit his carb target.
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 Jason’s losses are on the low 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 more
Jason has completed copious sweat rate tests over the years because he sweats a lot, so needs to dial his hydration plan according to race-conditions. During this race, he chose to increase the sodium concentration of his drinks to almost twice his sweat sodium concentration. This was based on his understanding that it would help his body retain as much of the fluid he was drinking as possible, and limit his overall sodium depletion. Jason mitigated the extent of this 'oversalting' by picking up plenty of plain water during the run, whilst carrying his own bottle of PH 1000. His perfect subjective hydration rating suggests he nailed this. The general scientific recommendations would be to reduce his sodium concentration, but considering the extremely warm conditions in Los Cabos and Jason’s high sweat rate, we wouldn’t recommend changing anything.
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.
Jason’s staple of using three PF 30 Caffeine Gels across a middle-distance triathlon served him well once again. His overall intake was inflated slightly by the small amount of caffeine in the on-course energy gels, but he still consumed a scientifically optimal amount to reap the maximum benefits.
How Jason hit his numbers
Here's everything that Jason ate and drank on the day...
Jason's weapons of choice
Jason's full stats
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.