Ironman New Zealand 2013 Results Analysis

The 2013 edition of Ironman New Zealand is now behind us. A vintage notable for being hotter than any recent year and also for the dethroning of the ‘Master of March’ – Cameron Brown. As usual I have distilled the results into summary data and have some observations about this years performances.

The first piece of information I’d like to offer is the summary table:

Summary Data Ironman

 2012 & 2006 not included – not IM distance

 The item that jumps out here is that 2013 has the slowest average Total time of any year shown. Followed shortly by the observation that the Run was markedly slower than the norm.

Something is afoot (and not just on the run).

Anyone who has read more than one of my articles will realise that I’m quite fond of modelling the cycle leg to evaluate conditions and equipment. So it should come as no surprise that I rushed to open the Ironman New Zealand model to see if that offered an explanation.

The wind was stronger than forecast – 9.3kph through most of the day, initially from the East but switching to WSW after a couple of hours on the bike. Pressure and humidity were low. The temperature recorded at the airport maxed at 26° but my Garmin recorded 32° on the course so I used my data (climbing from 12° to 32°).

After all of that, the difference in time thanks to conditions (as they relate to the physics of moving a bike) was that 2013 was 24s slower than 2011 for a 6hr10 rider (roughly the long term average). Clearly the environmental conditions are not to blame for slow times. Or are they…

Something that I don’t account for in the model is the effect of heat on the rider. Mainly because it is an individual factor and largely depends on how acclimated to heat the athlete is. For most of us (at least the New Zealanders) 32° is hot. Data from a few riders shows a marked slow down in the latter part of the ride as the heat ramped up. So it is likely that heat effects on the rider led to slower bike times and then a high level of physiological stress starting the run.

Another explanation that has been mooted is that the field was weaker than previous years. One of the metrics I track is the percentage of athletes that swam under an hour (Australia and NZ always have the highest scores here).

Swim times










Given that the lake was glassy and that most of the athletes I know had swim times in line with previous performances this could suggest that the field was a little weaker at the front end.

As in the movie Inception we’re going to have to go deeper.

In the 9 years of results used for this analysis 7314 people have competed at Ironman New Zealand but there are a high number of repeat offenders. So one way of analysing any particular year is to look at the relative performances of those athletes that have competed more than once.

Comparison table

The chart to the right tells us that for the recidivists, 2013 was, on average, 6.1% slower than their best performance at Ironman New Zealand. But only 1.3% slower than their average performance.

Breaking that down further we can see that the swim and ride were actually slightly quicker than average (though most people still slower than their bests) while the run was markedly slower and that is what spoils the overall times.

When I push the criteria for the ‘bests’ analysis out to those who’ve raced at least three times only 47 individuals had their best overall time in 2013 (out of 242).

From that we can conclude that Ironman New Zealand 2013 was not a fast edition for most athletes.

Was the field weaker? I’d give that a cautious yes. 61 athletes under 10hrs compared to 132 in 2011 and 99 in 2010. The usual sub10 suspects did their normal times but they just had fewer people around them. Of course – given the earlier mentioned heat factor it could be that a large number of athletes missed that target so the times are a reflection of preparedness not field strength. Which is why the ‘yes’ is a cautious one.

One area where it was not weaker was at the front. Bevan Docherty set a new race record by over 2 minutes. I’m not going to speculate on what his time would have been in better conditions but it’s worth noting that his 2.49 run is probably somewhat slower than his ability level. I’d also note that according to the ideal conditions for marathon records are ~13-14° – far cooler than what we experienced on Saturday.

Cameron Brown

Cameron Brown reflected the overall trend – Swim and ride at the usual levels but suffered on the run. And given that he’s been the most consistent performer in the last 11 years (place = 1) he’s a bit like a canary in a mine – a good indication of conditions.

And Meredith Kessler held out NZs strongest female, Gina Crawford, with an amazing swim, very strong ride and solid run. Gina was only 2 minutes slower than her best in 2009 which is the fastest year on record (125 athletes set their best times and most were significantly better than average) so has relatively improved on pre-baby performances.

In conclusion – despite conditions that were not conducive to personal bests – a number of athletes did achieve bests and new standards were set in the Elites. Which proves, once again, that preparation is by far the biggest factor in an Ironman performance.


  1. Hi David, nice analysis. What impact do you think that the new 3 lap run course had, given that this was the first year it was executed? It’s obviously more technical, not sure of the total vertical climb – could that have impacted on the times?

  2. Nice analysis. I also had a slow day compared to 2010 and considered dropping out on the run. Glad I didn’t, as my age group all struggled and I ended up winning it. So off to Kona again.

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