IM 70.3 Indian Wells
Marc'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.
Similarly to his IRONMAN 70.3 World Championships, Marc consumed more than 100g of carb per hour to fuel a strong finish. Despite the early race start time, Marc always plans to get a carb-rich breakfast in ~3 hours before the swim to ensure he’s starting well fueled. Marc focuses on being self-sufficient with his fuel on the bike by carrying one-third of a Flow Gel and PF Carb and Electrolyte Drink Mix in his various bottles. He also prefers not to rely on aid stations on the run, and switches to a 250ml soft flask containing maple syrup - one of Marc’s favourite carb sources - along with a PH 1500 packet to add a final 15g carb, topping off his high fueling intake throughout the speedy half marathon. This solid carb intake saw Marc plough through the run course to take second place.
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 Marc’s losses are High (1,146mg/L), nailing his hydration strategy remains important, even when it’s Mild.Learn more
In the mild race conditions, Marc implemented his hydration strategy effectively to replace a good proportion of his sweat losses. This involved using PF Carb & Electrolyte Drink Mix on the bike and concentrated PH 1500 on the run to take on a relative sodium concentration similar to that of his sweat sodium losses. On the bike, Marc had two further bottles with him, which he chose not to drink as he didn’t feel he needed to and he had a few additional sips of caffeinated energy drinks on the run. This worked well for Marc in these conditions, but we would recommend he collects some sweat rate data going forward to help refine his fluid strategy, especially going into hotter races where he’s admitted that he’s struggled to produce his best in the past.
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.
Marc has experimented with caffeine to perfect the timing of the stimulant's use on race day, in an attempt to maximise its ergogenic effects. He takes one PF 30 Caffeine Gel an hour into the bike, and then another 5 miles into the run. Given caffeine takes ~45-60 minutes to peak in the bloodstream, Marc’s strategy ensures he will enjoy a boost in his energy levels towards the back end of each of the bike and run legs. To reach what the research suggests is the optimal caffeine dose for endurance exercise, Marc may look to add one more caffeine gel to his race day strategy ~15 minutes before the start to sit within the recommended ranges.
How Marc hit his numbers
Here's everything that Marc ate and drank on the day...
Marc's weapons of choice
Marc'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.