Valencia Marathon

Lauren executed an improved fueling strategy, consuming ~76g/h of carbohydrate across the marathon by taking eight single-source carbohydrate gels spaced out every 5km. Lauren experienced some GI discomfort from around the 5th gel onwards, with nausea lingering until the evening. This is common when consuming high rates of single-source carbohydrates, as the gut's glucose transporters can become saturated. Lauren will continue gut training and transition to dual-source carbohydrates in 2026, allowing her to benefit from multiple sources of carbohydrate which can increase carbohydrate oxidation of external (ingested) carbohydrates and delay the use of muscle glyogen, which improves running economy and may enhance performance.

During the race, she kept fluid intake modest at ~232ml/h, which was appropriate for the mild Valencia conditions and relatively “short” race. She supplemented with two PH Electrolyte Capsules, one at 45 and another at 90 minutes, achieving a relative sodium concentration of 892mg/L - a decent match for her high sweat sodium losses, without over- or under-doing it.

Lauren experienced a mild calf twinge between 20-30km, which resolved after backing off the pace slightly. In hindsight, she felt a little over-hydrated early on, and pouring a full bottle of water over herself at one aid station left her feeling heavy from being covered in water. For future races, she'll look to be more conservative when pouring fluid on her clothes to avoid that heavy feeling. She’ll also play around in training with her pre-race hydration strategy to allow her to settle more easily into the opening kilometres without feeling as full.

Heat training

After a tough time in the Manchester Marathon during some warm weather eight months prior, Lauren completed nine sessions of heat training at the Precision Performance Lab ahead of Valencia, supplemented with hot baths between active sessions. She saw a 12% increase in running speed relative to her heart rate, while her within-session performance drop-off reduced from 18% to just 6% - meaning she could run for an hour at 39°C with minimal cardiovascular drift. This adaptation left her well-prepared for the conditions race day could have delivered.

Lauren used three-quarters of a caffeine gum pre-race (~75mg), which helped with the early morning start. Lauren felt very alert during warm-up - perhaps a little too alert initially - but was glad she took the dosage as the race progressed. At just ~1.5mg per kilogram of her bodyweight, there's likely room to increase her caffeine intake in future races to more closely align with the recommendations. This would involve Lauren building towards ~4mg/kg with some practice in training and smaller ‘B races’, perhaps using PF 30 Caffeine Gels to deliver a larger caffeine boost during the marathon.