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AI-DRAFTED — PHYSICIAN REVIEW IN PROGRESSThe citation for this entry was checked against Crossref and PubMed, but its summary and interpretation were drafted by an AI model from the published abstract and have not yet been individually read by a physician. Read the linked source before relying on this operationally.
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Heat preparation and nutrition strategies for a 100-mile ultramarathon in extreme heat: A questionnaire study at the Western States Endurance Run[1]

Mougin L, Stennett R, Ely BR, Taylor L, Adams WM, Blagrove RC, Longman DP, Mears SA · 2026 · J Sci Med Sport

Summary

Cross-sectional and prospective observational survey of runners in the 2025 Western States Endurance Run, a 100-mile ultramarathon with extreme heat exposure, using pre-race (n=106) and post-race (n=66) questionnaires on heat experience, acclimatisation/acclimation, nutrition and hydration, and race symptoms; finishers were grouped by time (<18 h, 18-24 h, 24-30 h). Most runners (90%) had completed heat preparation - acclimatisation 67%, acclimation 70%, with over 70% reporting more than 10 days or exposures - and 92% had planned mid-race cooling strategies, chiefly neck collars (89%) and cold towels (52%); 96% had tested their strategies in training. Faster finishers were more likely to have structured carbohydrate plans (<18 h 100% vs 24-30 h 69%; p=0.015) and higher sodium intake (p=0.007). Gastrointestinal symptoms occurred in 63% of finishers and 38% of those who dropped out and were most frequent in slower runners (p=0.045). The authors attribute the high preparedness and low rate of severe GI issues to strong pre-race communication, logistics and prior experience.

So what

The participant-side companion to the heat-communication-as-countermeasure argument: when the organiser's pre-race communication and logistics are strong, protective behaviour is nearly universal (90% heat-prepared, 92% with a planned cooling method, 96% having rehearsed it) rather than aspirational. For an event medical planner it reframes cooling from something the medical tent does after collapse to something the field is already doing to itself - if the organiser primes it - which lowers the severe-case load the tent has to absorb. The practical read: publish heat-prep and cooling guidance ahead of a hot endurance event, make simple cooling (neck collars, cold towels) available and expected, and treat GI symptoms as a slower-runner and drop-out marker worth provisioning for. Caveats: self-reported questionnaire in an elite, self-selected ultra field (highly heat-literate, not a general mass-participation crowd), and a declared sponsor conflict of interest for one author - cite for the preparedness/communication mechanism, not as evidence a cooling method reduces hard clinical endpoints.

Key findings

  • 2025 Western States 100-mile ultramarathon; pre-race n=106, post-race n=66 surveys
  • 90% completed heat preparation (acclimatisation 67%, acclimation 70%; >70% did >10 days/exposures)
  • 92% planned mid-race cooling - neck collars 89%, cold towels 52%; 96% tested strategies in training
  • Faster finishers had structured carbohydrate plans (100% vs 69%, p=0.015) and higher sodium intake (p=0.007)
  • GI symptoms in 63% of finishers / 38% of drop-outs, worst in slower runners (p=0.045); high preparedness credited to pre-race communication (self-report; sponsor COI noted)

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