Sex difference in race performance and age of peak performance in the Ironman Triathlon World Championship from 1983 to 2012

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.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).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.The sex difference in endurance performance has been investigated for swimming [1-4], running [5-8], and multi-sports disciplines such as triathlon [9-13] and duathlon [14]. While some authors argued that women might be able to reach men's endurance performance [5,15,16], others suggested that the sex difference is of biological origin and that women would not be able to approach men's performances [7,17,18]. The sex difference in performance is mainly explained by differences in physiological and anthropometric charact