Precision Fuel & Hydration IRONMAN 70.3® World Championship

Ant followed an aggressive fueling strategy on the bike, taking in ~142g of carbohydrate per hour from a combination of PF 300 Flow Gel and two PF 30 Caffeine Gels. By front-loading his carb intake during the bike leg, he ensured he began the run with high energy availability. He adjusted his intake to ~75g/h whilst running by using a mix of caffeinated and non-caffeinated PF 30 Gels. Because running often reduces gut comfort and blood flow to the GI tract, this slightly lower, yet still decent, rate of carb intake helped him maintain energy delivery without risking GI distress. His consistent pacing throughout the half marathon suggests the strategy worked effectively, with steady energy availability all the way to the finish.

Ant consumed just over ~1L of fluid per hour on the bike, starting with 750ml of PH 1500 (Tablets) on his bike frame before picking up two bottles of PH 1000 at on-course aid stations. The combined relative sodium concentration of these drinks was within ~100mg/L of his sweat sodium concentration, allowing him to effectively replace his sodium losses and avoid dehydration-related symptoms. This also supports fluid retention and blood volume maintenance, which are crucial for effective thermoregulation. On the run, his fluid intake decreased to ~600ml/h, and while this was a reduced rate of intake compared to the bike, it was likely still enough to support hydration status. He began with a soft flask of PH 1500 and collected additional cups of PH 1000 on the course.

With an exceptionally high sweat rate, Ant relied on a well-practised hydration strategy to minimise fluid loss during the race. Pre- and post-race body mass measurements showed a 2.9% reduction; still within the range where performance can begin to be negatively affected. So, slightly increasing his intake in similar future race conditions may help reduce total fluid loss even further and account for his extra high losses.

Ant used caffeine strategically, spreading his intake across the race rather than opting for one large dose. His total race-day caffeine intake reached ~6.67 mg/kg, which sits at the upper end of evidence-based recommendations, but it was clearly well tolerated by Ant. His staggered approach supports sustained central nervous system stimulation and helps maintain pace as fatigue accumulates, working well to support his performance on the day.