Master runners dominate 24-h ultramarathons worldwide-a retrospective data analysis from 1998 to 2011

Background: The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. Methods: Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. Results: The number of 24-h ultra-marathoners increased for both women and men across years (P < 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 +/- 5.2 years for the annual fastest men (P > 0.05). The age of the annual top ten women decreased from 42.6 +/- 5.9 years (1998) to 40.1 +/- 7.0 years (2011) (P < 0.01). For the annual top ten men, the age of peak running speed remained unchanged at 42 +/- 2 years (P > 0.05). Running speed remained unchanged over time at 11.4 +/- 0.4 km h(-1) for the annual fastest men and 10.0 +/- 0.2 km/h for the annual fastest women, respectively (P > 0.05). For the annual ten fastest women, running speed increased over time by 3.2% from 9.3 +/- 0.3 to 9.6 +/- 0.3 km/h (P < 0.01). Running speed of the annual top ten men remained unchanged at 10.8 +/- 0.3 km/h (P > 0.05). Women in age groups 25-29 (r(2) = 0.61, P < 0.01), 30-34 (r(2) = 0.48, P < 0.01), 35-39 (r(2) = 0.42, P = 0.01), 40-44 (r(2) = 0.46, P < 0.01), 55-59 (r(2) = 0.41, P = 0.03), and 60-64 (r(2) = 0.57, P < 0.01) improved running speed; while women in age groups 45-49 and 50-54 maintained running speed (P > 0.05). Men improved running speed in age groups 25-29 (r(2) = 0.48, P = 0.02), 45-49 (r(2) = 0.34, P = 0.03), 50-54 (r(2) = 0.50, P < 0.01), 55-59 (r(2) = 0.70, P < 0.01), and 60-64 (r(2) = 0.44, P = 0.03); while runners in age groups 30-34, 35-39, and 40-44 maintained running speed (P > 0.05). Conclusions: Female and male age group runners improved running speed. Runners aged > 40 years achieved the fastest running speeds. By definition, runners aged > 35 are master runners. The definition of master runners aged > 35 years needs to be questioned for ultra-marathoners competing in 24-h ultra-marathons.