Los Angeles Marathon

Running his first ever marathon alongside his brother Andy, Dave arrived at the start line in Los Angeles having consumed ~130g of carbohydrate (~1.7g/kg) to meet the race morning carb recommendations and top up his fuel stores, before taking a final carb dose in the form of a PF 30 Caffeine Gel 30 minutes before the gun. Without the assistance of PF Carb & Electrolyte Drink Mix that Andy leant on during the race, Dave used PF 90 Gels and PF 30 Caffeine Gels to average ~75g/h across the 3 hours 14 minutes on course. This is a step up from his last endurance event, where he averaged ~57g/h at the Jurassic Coast Challenge in 2024, which he managed with impressive gut comfort despite working at a higher relative intensity during the marathon. Dave did back off briefly when he felt full around the halfway point, which slowed his second PF 90 Gel down but other than that felt well fueled and comfortable until he stopped fueling from 30km (19 mile) onwards. A late call-up to the race meant Dave wasn’t able to dedicate enough time to train his gut to handle his target amount across the race. He would have benefited from dedicated gut training sessions in the build-up, which would stand him in better stead next time to aim for the recommended 90g/h for this duration and intensity until the very end of the race.

With warm predicted conditions, Dave chose to start the race with two 500ml soft flasks of PH 1500 (Tablets) and supplement with cups of water at each aid station. He averaged a fluid intake of ~619ml/h across the race, a sensible level for his sweat rate of ~0.93L/h (67% fluid replacement). Pre- and post-race bodyweight measurements confirmed that Dave finished the race just 0.78% lighter, well clear of the 2% threshold thought to impact performance. Compared to Andy's 3.1% body weight reduction, this shows Dave's fluid intake was sufficient. However, his relative sodium concentration sat well below his sodium losses as a very salty sweater - this sodium deficit could have played a part alongside fatigue in his late-onset cramping in the final 2km. Carrying a few Electrolyte Capsules to take alongside the water he picked up at aid stations from the start would be a simple, practical way to close that gap without much additional complexity.

Consuming two PF 30 Caffeine Gels on race day put Dave just below the general recommendations for races 3–5 hours in duration. Another well-timed dose, such as one PF 30 Caffeine Gel with 10km to go, could have maintained his blood caffeine levels in the range proven to reduce the perception of effort when he needed it most.