Lacambra, Lucas A.

This study leverages an experiment of nature framework to examine sex-based differences in ultraendurance swimming using English Channel performance data. Males were faster than females, with the greatest differences observed among older swimmers and top performers. Performance was optimal in moderately cool water temperatures (17–18°C). These findings highlight how naturally occurring endurance events provide unique opportunities to study physiological limits and the combined influences of sex, age, and environment on human performance.