Analysis of ultra-triathlon performances From the years 1985-2009 we found a total of 73 triathlets (68 men and 5 women), which have completed twice, three times and a tenfold Ironman during their career. The slash pages for swimming, cycling and running we have correlated with the corresponding competition time as well as the competition times for double and tripled Ironman over time for ten times. Based on this evaluation, we have developed a formula with which one can calculate the expected competition time in a tenfold Ironman. The formula can be found in https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3781891/