IRONMAN® World Championships

After a couple of issues in his previous race with the logistics of carrying nutrition, Mathias adjusted his plan to ensure that in the event of a lost bottle he would still hit his target intake of 90 grams of carbohydrate per hour. Fortunately, this time out all bottles remained safely in their cages and Mathias was able to stick to his plan, which included several bottles of over-concentrated PF Carb & Electrolyte Drink Mix, almost an entire PF Flow Gel, and a PF 30 Caffeine Gel over the course of the bike and run.

Mathias’ total carbohydrate intake of ~735 grams, equivalent to ~2940 calories, was a key player in his performance. Research indicates that through an adequate carb-load before a race, triathletes hit the start line with ~500-600 grams (or 2000-2400 calories) of carbohydrates stored as muscle glycogen (and a small additional amount in the liver). Glycogen depletion rates vary throughout the race depending on the intensity at which an athlete is racing and the muscles being used. Larger muscle groups (i.e. the quadriceps), both store and utilise a significant amount of muscle glycogen, compared with smaller muscle groups (i.e. the triceps or biceps), so it is no surprise that the majority of glycogen depletion occurs during the bike leg of the race. The research has suggested that during high intensity exercise (i.e., 85% of VO2 max or 120% of LT1), similar to that of the pro athletes at the IRONMAN® World Champs, glycogen utilisation can exceed 2-3 grams per minute, correlating to >120-180g/h of carbohydrates. Considering this, without fueling during exercise, glycogen reserves can be depleted within ~2-3 hours. However, by consuming 90g/h, Mathias would have delayed this depletion, sustaining his blood glucose levels, and subsequently fueling his performance perfectly for this seven+ hour race.

In the week leading up to the race, Mathias visited our team at the Expo to get a Sweat Test. He discovered that his sweat sodium concentration was on the lower end, losing 409 mg of sodium per litre (~32oz). Since he’d already prepared and practised his previously determined strategy in training, he decided not to make any last minute changes and continued to aim for ~1,000mg/L. Given the conditions in Kona, with both high temperatures and humidity, very high sweat rates were expected, and slightly over-salting his drinks relative to his sweat sodium concentration would’ve helped him retain more fluid and prevent dehydration. His subjective feedback and frequent urination suggests he was well-hydrated throughout, although in cooler races he could afford to lower his relative sodium intake to be more in line with his losses.

We know that caffeine has the potential to mask fatigue through increasing time until exhaustion, improve focus, and reduce the perception of effort during endurance exercise. Given these key mechanisms to improve performance, Mathias could increase his consumption of the stimulant. His morning coffee(s), and singular Caffeine Gel on the run would’ve circulated some caffeine through his bloodstream, but still put him below the recommended dosage. Mathias did plan to have some additional caffeine from another caffeinated gel mixed into one of his bottles on the run course, but due to the fullness he felt, he didn’t pick it up. Carrying a spare Caffeine Gel in his tri-suit pocket could be helpful to ensure that even when he doesn’t want to drink any more fluid, he can still reap the benefits of caffeine.