Ironman Wisconsin 2002-2010: Did Not Start (DNS) and Did Not Finish (DNF) Rates

By Raymond Britt -- Conditions on race day can affect Ironman triathlon outcomes, in terms of DNF (Did Not Finish) rates. Held in September and known for unpredictable weather, Ironman Wisconsin is one race where condition and DNF (Did Not Finish) rates have varied considerably from year to year. [Also see our North American Ironman DNF Rate Comparisons]

I've competed in five Ironman Wisconsins, from cool days to scorchers, from a low of 4% in the inaugural year (though 16% registered but did not start) to 19% in 2005. Competitors in 2003 and 2005 were faced with 90-100 degree conditions; 2006 was a freezing, rainy, awful day, while 2008 and 2009 were perfect.  In recent years, the race norm seems to be a 10% to 12% DNS rate and a 5% to 6% DNF rate, which is reflected in our RunTri's Toughest 25 Ironman Triathlon analysis. Even in perfect conditions, Ironman Wisconsin rates a top 5 Most Difficult races rating.

Ironman Kona 2010 Participants by Age

The 1925 triathletes planning to compete at Ironman Kona Hawaii 2010 represent ages 18 to 80+. For more, see the participant list,  Kona Qualifying Times and our  Complete Kona Coverage.

Number of Annual Ironman Triathlon Finishers

By Raymond Britt -- In the last twelve months, more than 41,000 triathletes finished 25 Ironman Triathlons. Each finisher met the daunting challenge of a 2.4 mile swim, a 112 mile bike and a 26.2 mile marathon. Of the finishers, nearly 1600 qualified to compete in the 2010 Ironman Triathlon World Championship.

If you add non-Ironman branded Ironman distance races to the mix, such as Challenge Roth, we estimate a global total of 50,000 finishers. While there is no such thing as an easy Ironman, some were clearly more difficult than others. Our data shows between 5% and 7% DNF rates for most events. Ironman St. George and Louisville, however, posed extraordinary difficulty in 2010; each had DNF rates around 15%. See RunTri's Ranking of 25 Toughest Ironman Races for details.