35 Years of Ironman Statistics: The Run

Mirinda Carfrae (AUS) on run at the Ironman World Championship in Kailua-Kona, Hawaii on October 11, 2014

Our last installment of this series broke from our analysis of performance in the individual disciplines to provide a little context on bike splits. This installment demands that we begin with context. The history of Ironman forbids us from talking about the run in a vacuum. The run has always led to the race’s defining moment at the finish each year, but it couldn’t possibly be the epic conclusion it is without the extraordinary drama preceding it.

It began with the first race in Honolulu in 1979. Gordon Haller didn’t take the lead until late in the run as Navy SEAL John Dunbar suffered a Budweiser-induced bonk while trying to run the most epic beer mile in sports history after his support crew ran out of water.

Then there was Julie Moss‘s agonizing crawl across the finish after her legs failed her in the yards ahead of the finish. Her storied runner-up finish, shown live on ABC’S “Wide World of Sports” put Ironman on the map. Of course, there was Allen and Scott’s legendary step-for-step battle during the famous 1989 “Iron War.” But who can forget Chris McCormack shaking hands with Andreas Raelert in the final miles of the 2010 World Championships, in what was possibly the most dubious psych-out since Amasis hypnotized twelve Chikara opponents at once.

Even today, the swim and the bike set the run up as the moment of truth. How has that moment played out over the decades? Cue the graphics…


We’re showing the men’s and women’s trends without interruption because the pictures speak volumes for themselves, and again context enhances our understanding of what we see.

To begin with, we see the definitive “performance eras” again– rapid improvement between 1985 and 1991, a less clear trend of improvement from 1991-2005, and the “leveling out” from 2006 to the present. Again, women and men follow the same general pattern, indicating the influence of weather conditions.

What becomes interesting then is that we see the bike and run trending most closely to overall finish time, whereas swim performance has become so consistent as to hardly be influential at present. The data therefore reinforces the point Nick White made in our tangent discussion about power on the bike that the bulk of an Ironman race is an optimization problem.

You have to balance effort on the bike against effort on the run according to how quickly your body can process calories. Therein lies another implication. If both cycling and running performances are reaching an absolute maximum, does that mean our elite athletes have hit the ceiling of human potential? Is there literally no more room for improvement? We’ll take a deeper look at that relationship in the future.

But to get away from the context and enjoy statistics about the run itself for a while, here are the fun facts to discuss over the snack bowl while you watch Ironman Live this October…

  • The male champion in Kona has run the fastest marathon 24 times. The women’s champion has been the fastest runner on 20 occasions.
  • The women’s champ has been the fastest runner in 7 of the last 10 races. The men’s champ in only 4 of the last 10.
  • At least one woman has run fast enough to place among the top ten men 18 times. On two occasions the fastest woman beat out the fastest man. That woman was Mirinda Carfrae.

Compared to the historical correlation between the swim or bike and the overall time, it seems evident that the run is the definitive weapon at Kona. A few professional athletes and coaches have contacted me with further thoughts on this dynamic. Some have complained about an “arms race” between “haves and have-nots” on the bike, in which top-tier pros enjoy the benefit of the latest and greatest aerodynamic gear from sponsors with better technology and deeper pockets.

Others have claimed that certain athletes get a pass on drafting penalties because they’re crowd favorites and WTC doesn’t want to muddy results in the front of the pack with controversial officiating. There are no such ambiguities after T2. It’s just you and your feet against the others. The responses have been numerous and similar enough that it seems even within the optimization problem of effort balance and caloric processing, there are certain games athletes can play. Who plays them and how successful they are at it is another consideration in our ongoing breakdown of the Ironman World Championships.

That concludes our assessment of the three individual disciplines. As expected, this series has turned up as many questions as answers. But now that we’re familiar with the dynamics in each sequential component of the event, we’ll start putting the pieces together and see how much greater the sum is than the individual parts. Our next installment will be the second half of our beyond-the-numbers investigation of the bike split, focusing exclusively on aerodynamics and how they might be influencing the times.

If you enjoyed this analysis of Ironman statistics, check out Part 1 (overall performance) and Part 2 (swim) and Part 3 (bike) and Part 4 (bike power).

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About the Author

Jim Gourley is the author of Faster: Demystifying the Secrets of Triathlon Speed and The Race Within: The Story of the Ultraman Triathlon. He is a regular contributor to Tom Ricks' blog "The Best Defense." His work has been featured in Men's Health, Stars and Stripes, and several triathlon and cycling publications.