Ironman Cut-off Times: Can it Really Take 17 Hours to Finish an Ironman?

The Challenge and the Reward: As famously written in on the last page of the first race instructions by Ironman founder John Collins: "Swim 2.4 miles! Bike 112 miles! Run 26.2 miles! Brag for the rest of your life".

How much Time is Allowed to finish? To earn those bragging rights it's this simple: complete the race in less than 17 hours (with exceptions such as France and Germany, with 16- and 15-hour limits, respectively), and you're an official Ironman finisher. (on average, it takes 12 hours, 35 minutes to finish)

How many need 17 hours to finish? In a typical North American ironman around 85% of finishers cross the line under 15 hours, and nearly 95% cross the line in less than 16 hours.  For example, at Ironman Florida 2011, 2353 triathletes finished the race; of those, 192 finished between 16 and 17 hours, and another 92 finished between 16 and 17 hours.

What's the difference in race splits and finish times between 15- and 16-hour finishers? In short, more than half is on the run. We compared swim, bike and run splits, and finishing times, of 15- and 16-hour finishers at Ironman Florida 2011, and the results are:
  • Overall: 16-hour finishers take 56 minutes longer to finish
  • Swim: only 5 minutes separate 15- and 16-hour finishers
  • Bike: 16-hour finishers use 19 extra minutes on the bike, but that's only a 4% increase over 15-hour finisher splits
  • Run: runners who finish in 16 hours take 32 minutes longer to complete the marathon, a notable 9% increase over 15-hour finishers

Generally, the distribution of 16- and 17-hour finishers is somewhat similar to that of all the entire field: most are are male, between 35 and 45, for example.

How do the results -- additional time in swim, bike and run splits -- vary by age group? Here are the results.