No gender difference in peak performance in ultra-endurance swimming performance - analysis of the 'Zurich 12-h Swim' from 1996 to 2010

The aims of the study were to [1] investigate the performance trends at the ‘Zurich 12-h Swim’ in Switzerland from 1996 to 2010; and [2] determine the gender difference in peak performance in ultraendurance swimming. In total, 113 male and 53 female swimmers competed in this indoor ultraendurance event while swimming in a heated pool. The number of male participants significantly increased (r2 = 0.36, P = 0.04) over time while the participation of females remained unchanged (r2 = 0.12, P = 0.26). In the age group 0.05). The best performance was achieved in the age groups 30-39 years and 40-49 years for both genders, respectively. The athletes in the age groups 0.05). The best male and female swim performances remained unchanged across the years. Females are able to achieve a similar swim performance in an indoor ultra-endurance swim event of ~40 km. Further studies are needed to investigate whether females are able to achieve similar or even better performances than males in openwater ultra-swimming events such as ‘Channel Swimming’