Temperature-driven modulation of factors influencing full-Marathon time in male recreational runners.

The weather during full-marathon events is expected to become warmer due to global warming, making heat preparations a key challenge for runners. To gain insight into this challenge, we examined whether associations between full-marathon finish time and selected factors differed across the Tsukuba Marathon 2023 and 2022, and the Hokkaido Marathon 2023, which represent optimal, moderate, and extreme temperatures, respectively. Questionnaire-based measurements of full-marathon personal best (PB), age, running experience (career), body mass index (BMI), weekly running distance and frequency, longest running distance, and finish time were analyzed using hierarchical multiple regression analysis, followed by simple slope analyses for significant interactions. The analysis included 1938 male runners. Event-based ambient temperature conditions independently explained approximately 11% of the variance in finish time. Temperature conditions significantly modulated the relationships between finish time and PB, age, career, and BMI, whereas no such effect was observed for running distance, frequency, and longest run. Specifically, the temperature-related increase in finish time tended to be greater in runners characterized by faster PB time, older age, lower career values, and higher BMI. Running capacity, age, running experience, and BMI may serve as key targets in strategies to counteract heat-related marathon performance decline in male recreational runners.