title: Sex difference in race performance and age of peak performance in the Ironman Triathlon World Championship from 1983 to 2012.
abstract: BACKGROUND
  The fastest Ironman race times in 'Ironman Hawaii' were achieved in very recent years. This study investigated the change in sex difference in both race performance and the age of peak performance across years in the top ten athletes for split disciplines and overall race time in the 'Ironman Hawaii' between 1983 and 2012.
  
  
  METHODS
  Changes in split times, overall race times, and age of athletes across years for the top ten overall and the fastest swimmers, cyclists, and runners were investigated using regression analyses and analyses of variance.
  
  
  RESULTS
  Between 1983 and 2012, the overall top ten men and women finishers improved their swimming (only men), cycling, running, and overall race times. The sex difference in overall race time decreased significantly (p = 0.01) from 15.2% to 11.3% across time. For the split disciplines, the sex difference remained unchanged (p > 0.05) for swimming (12.5 ± 3.7%) and cycling (12.5 ± 2.7%) but decreased for running from 13.5 ± 8.1% to 7.3 ± 2.9% (p = 0.03). The time performance of the top ten swimmers remained stable (p > 0.05), while those of the top ten cyclists and top ten runners improved (p < 0.01). The sex difference in performance remained unchanged (p > 0.05) in swimming (8.0 ± 2.4%), cycling (12.7 ± 1.8%), and running (15.2 ± 3.0%). Between 1983 and 2012, the age of the overall top ten finishers and the fastest swimmers, cyclists, and runners increased across years for both women and men (p < 0.01).
  
  
  CONCLUSIONS
  To summarize, for the overall top ten finishers, the sex difference decreased across years for overall race time and running, but not for swimming and cycling. For the top ten per discipline, the sex difference in performance remained unchanged. The athletes improved their performances across years although the age of peak performance increased.
authors.affiliation: Institute of General Practice and Health Services Research, University of Zurich, Zurich, 8091, Switzerland. beat.knechtle@hispeed.ch.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Rüst
authors.forename: Beat
authors.initials: B
authors.lastname: Knechtle
authors.forename: Thomas
authors.initials: T
authors.lastname: Rosemann
authors.forename: Romuald
authors.initials: R
authors.lastname: Lepers