Easiest Half Ironman 70.3? Hardest? RunTri's Ranking of Best Half Ironman Races

By Raymond Britt -- There is no such thing as an easy Half Ironman. Covering 70.3 miles on any course, any day, in any variety of conditions, is a monumental challenge. Everyone who crosses the finish line knows how hard a half ironman can be. But we were curious . . .  RunTri analyzed nearly 95,000 triathletes competing in 40 70.3 distance triathlons to answer the question: which half ironman triathlon is hardest? Easiest? We've completed this analysis twice, and both are presented here.

RunTri's Toughest/Easiest Ironman 70.3 Races

We've taken our original analysis of 35 Ironman 70.3 events, expanded the list to 40 races, and then dug deeper, ranking races by discipline -- swim, bike or run -- to help athletes more accurately assess which races are easiest or toughest, depending on which elements of their triathlon skills are best or weakest. (we know you'll have many questions; see FAQs further down in this post)

RunTri's Original Top 35 Toughest/Easiest Ironman 70.3 Races

Next, our original analysis, the Top 25 Toughest/Easiest Ironman Races and related analysis. Our original analytics in response to key questions about comparing the races still hold true for the new rankings.

Top 5 Toughest Half Ironman 70.3 Races: Branson, UK, Japan, and the Philippines. Boise was in the top five originally; dramatically faster results in 2011 will move Boise to the middle of the pack next time we revise the complete rankings.

Half Ironman Triathletes. In the 2010-2011 season,  67,500 triathletes registered to compete in 40 of the world's best half ironman distance events, or about 1700 per race, on average. In 2012, about 95,000 athletes were registered to compete in one of 62 races.

For further details and links to data for each race, see  Index of  Best Half Ironman 70.3 Races.

For similar comparative charts, see our analysis of toughest half Ironman 70.3 swim, bike, run courses.

We've compared Ironman and half ironman 70.3 races, and have found that about 50% or your time in a triathlon will be on the bike.

Further, see out bike/run correlation analysis to get an idea of what your run split should be in a half ironman, depending on bike course difficulty.

Wondering what your Ironman finish time might be, based on your half Ironman 70.3 time? See our Analysis of Ironman Finish Targets vis a vis Half Ironman Finish Times

Between 10% and 20% of those who sign up to compete in a half ironman will not start the race. Another 3% to 8% will DNF.

• Want more of our comparisons? See our Easiest/Hardest Ironman Couse Comparisons
• Even more? See our Analysis of 25 Best Marathon Races

Toughest. The UK Ironman also ranks among the toughest Ironman distance races.  Branson's challenging bike course left many short of energy on the run. Philippines triathletes fared well on the swim and bike, but the run -- the toughest of those we've ranked -- that landed it on this list. Both UK races -- 70.3 and Ironman -- rank as top 5 toughest.

Clearwater. The 70.3 World Championship in Clearwater has the fastest time, but we expect that, because of the world-class line-up of athletes racing there. Same is true with Ironman Kona; it ranks as fastest among the 25 Ironman races we've analyzed. For now, Clearwater is left out of the charts.

Fastest.  Brazil, Austria and Pucon are clearly the fastest courses of this group. We're not sure what to make of Brazil's times; they might be too fast. Austria's rank is similar to the country's full Ironman distance race. Steelhead triathletes turned in very fast times this year, as did those in Kansas and Mooseman, making these the four fastest half Ironman courses.

In-Between. As for the rest, at 6+ hours, they all are proof that there is no such thing as an easy half ironman. Once you're on the course in any of these races, you're going to have the challenge of your lifetime, and the finish will be something to be proud of, forever.

Comparisons Year to Year: Variances in weather conditions take less of a toll on half ironman triathletes; finish times don't tend to vary widely from one year to the next due to weather. Example: comparing Half Ironman 70.3 2009 and 2010 average times, overall and by age group.

Other Races: There are several additional Ironman 70.3 races, some of which will be added over time, as race results become available. 

Notes on Methodology: see notes in  our post of Hardest/Easiest Ironman, nearly all apply here. 

Predicting Your Ironman Finish Time, Based on Half Ironman 70.3 Results

One of the frequent questions we hear: What can I expect my ironman time to be, based on my half ironman finish time in another race?

The answer, based on our analysis of 25 top ironman race times and 25 top half ironman race times: on average:

Full Ironman Time = half ironman time * 2.1 = 2x half ironman time + 40 minutes

Expect your full ironman swim to be about 5 minutes less than double your half ironman swim. Double your bike split and add 15 minutes. And double your half ironman time and add about 30 minutes. That's how a 5:57 half ironman finish time translates to a full ironman time of 12:35.

• How Much Time Does it Take to Finish an Ironman?
• How Much Time Does it Take to Finish a Half Ironman?

To address the naturally occurring variations from race to race, we have matched full- and half-ironman distance races that take place on the same course (e.g., China), races that take place in the same country, and races that appear to share common characteristics such as climate, terrain, etc.

These pairings are, of course, subject to change. Use your race experience and the data on this chart to predict a most accurate ironman finish time based on your half ironman results.

For more, see our new analysis by Age Group for New Zealand and Texas vs New Zealand.

For more, see our Analysis of Top 25 Ironman Races and Top Ironman 70.3 Races.

Ironman Kona 2015 Results Analysis and Comparative Statistics

Ironman Kona 2015 Results Analysis: Overall,  Splits, by Division, Correlation, Annual Comparisons

By Raymond Britt

The 2015 Ironman Triathlon World Championship proved once again to be one of the most exciting, challenging, unpredictable and majestic in the world of endurance sports. This year lived up to these elements, with surprise first-time winners, a record number of starters and finishers, a higher than average finish time (overall and by age group).

Before and after my years of qualifying for and racing in Kona: 2002 to 2004) I've compiled comprehensive analysis on the path to qualifying for Ironman Kona, To provide this unique view, I've gone deep into annual race data to provide detailed and exclusive analysis for triathletes who want to understand the true dynamics of the event.

Our initial analysis of the somewhat more comparatively difficult 2015 race is below in thirteen charts. Here are just some the highlights:

1. Starters: Most in Ironman History: 2,370, 12.3% over 2014, and most since at least 2002
2. Finishers Most in Ironman History: 2,000+, 10.8% growth over 2014, most since at least 2002 
3. DNF rate, 6.7 vs 6.0% in 2014, and only topped in years 2004 and 2009 since 2002
4. Average Finish Time for all Finishers: 11:44, other than 2004 lowest going back to 2002
5. Average Overall Splits: Swim 1:16 (11%), Bike 5:53 (50%), Run 4:23 (37%), Transitions 0:11
6. Splits for each race division are shown, and by and large, reveal a similar pattern vs overall
7. Comparing Splits 2009 to 2015: the 5:53 bike is about average, but the 4:23 run is worst
8. Finish Times by Division 2014 vs 2015: notably slower in typically stronger divisions 30s-40s
9. Total Finishers, Growth 2013 to 2015: new trend vs a many years of limits around 1800
10. DNF Rates for each Division 2014 vs 2014
11. Correlation Between Bike snd Run Splits for each athlete plotted on a single chart that illustrates the tendency of more athletes cycling too fast, followed by slower runs
12. Division Comparisons (2 pages): Average Finish Times by age group 2009 to 2015
13. Everything Else For all of our comprehensive Kona posts of past years, see www.RaceKona.com

Hardest/Easiest Ironman by Age Group: 25 Races Compared

We took our analysis of 50,000 triathletes competing in 25 Ironman triathlons, and went deep into the race divisions to define the hardest races by age group. Here are the results for men; top 5 hardest per age group are highlighted in red. By Raymond Britt.

Click on chart to see full-size table.

• For further details and links to data for each race, see Detailed Comparisons between races.
• For similar comparative charts, see our Toughest/Easiest Swim, Bike, Run and Overall analyses.
• For even more, see  details by race and by age group 

Ironman Texas 2014 Results Analysis: Overall, By Division, by Split, vs Previous Years and more

The results of Ironman Texas 2014 clearly show that, once again, the event maintained its position as one of the tougher full Ironman races in the world. How tough? A 13:16 average finish time (similar to 13:18 in 2012 but much slower than the average for all global Ironman events we've analyzed -- 12:35) and a 9.9% DNF rate, about double the average North American Ironman DNF result. Yet it could have been worse: Ironman Texas 2013 resulted in an average finish time of 13:40 and DNF of 17%.

But don't let the numbers overshadow a most important point: Ironman Texas is a great event, very popular on the Ironman circuit, and it comes highly recommended by well over 2,000 participants each year.

Our complete results analysis -- overall, by division, by split, vs previous years and more -- show specifically how challenging the event was this year.

For more, see:

• RunTri's Toughest/Easiest Ironman Triathlons
• Ironman Texas 2012 Results Analysis
• Ironman Texas 2013 Results Analysis
• How Much Time Does it Take To Finish an Ironman
• RunTri's Archive of Ironman/Marathon Stats/Analysis/Results
• Run/Tri Home/Site Map

Toughest/Easiest Ironman Courses: Index of S/B/R Splits by Race and Age Group

RunTri analyzed nearly 50,000 triathletes competing in 25 Ironman distance triathlons (in 2010 season) to answer the question: which Ironman triathlon is hardest? Easiest? The results are here. By Raymond Britt

Race: Ironman Splits by Age Group can be accessed via race name links.

• Kona: number of qualifying slots per race; like leads to list of athletes qualified for Kona 
• Swim, Bike, Run:  column headers link to charts comparing all 22 races
• Finish: Complete Race Results can be accessed via the finish time links
• RT: Click to see RunTri's Exclusive coverage for these races
• For more,  see our Index of Comparative Splits by Age Group Analysis.
• See our notes on methodology and factors here.

Here's the Graphic View of data above.

Toughest/Easiest Ironman Swim Course: Comparing 25 Ironman Races

There are fantastic swim courses on the worldwide ironman circuit. Among my favorites are Kona, New Zealand and Florida. I've completed the Ironman swim in 29 races, and while I'm not a great swimmer, my swim times have sometimes varied from course to course more than expected.

So I did an analysis of 100,000 Ironman finishers to try to answer the question: Is it possible that the degree of difficulty swimming 2.4 miles differs by location?

The data says yes, if you assume that all swim courses are measured reasonably accurately. Here's how they compare on average. Then continue reading: there's much more to the story. 

Factors that impact average swim times can range from a very tight swimming venue, very rough open water, or speedy currents. And these factors can have dramatic impacts. 

In the slightly dated chart above (newer one to be posted soon) comparing 25 Ironman swims, Cozumel is shown as one of the fastest at an average 1:08 split. However, at Ironman Cozumel 2012, the average time was 1:28:59, see chart below. Reports from Cozumel swimmers indicated a particularly challenge last section of the swim, and some athletes described their times as 10-15 minutes slower than they expected.

And swimmers at the Ironman US Championship 2012 in New York City cruised with the current to an average 51 minute swim split.

Want to dig deeper: here's the data for every race and every age group:


Ironman Average Finish Times and Swim, Bike, Run Split Comparisons

North America Finish, Split Times by Age Group Ironman Arizona Ironman Canada Ironman Coeur d'Alene Ironman Florida Ironman Lake Placid Ironman Louisville Ironman New York US Championship Ironman Mont-Tremblant Ironman St. George Ironman Texas Ironman Wisconsin Europe / South Africa Finish, Split Times by Age Group Ironman Austria Ironman Germany Ironman France Ironman Lanzarote Ironman Regensburg Ironman South Africa Ironman Sweden Ironman Switzerland Ironman UK Ironman Wales Asia/Pacific Finish, Split Times by Age Group Ironman Australia Ironman Korea Ironman Melbourne Ironman New Zealand Ironman Western Australia Central/South America Finish, Split Times by Age Group Ironman Brazil Ironman Cozumel Male Age Group Finish, Split Times by Ironman Male 18-24 Male 25-29 Male 30-34 Male 35-39 Male 40-44 Male 45-49 Male 50-54 Male 55-59 Male 60-64 Male 65-69 Male 70-74 Male Pro Female Age Group Finish, Split Times by Ironman Female 18-24 Female 25-29 Female 30-34 Female 35-39 Female 40-44 Female 45-49 Female 50-54 Female 55-59 Female 60-64 Female Pro

For even more detail on all races, visit our Toughest/Easiest Ironman Race Analysis and our Complete Archive of Stats and Results Analysis.

Ironman 70.3 Boise 2012 Results Analysis (Shortened Course)

Ironman 70.3 Boise is one of several WTC races -- Steelhead 70.3, New Zealand, Muncie 70.3, e.g., that have altered course distances based on expected extreme weather.

At Boise, due to expected extreme cold and windy conditions on race day, organizers revised the course from a 56 mile bike ride to a distance of 13.69 miles, while keeping the usual half ironman distances -- 1.2 mile swim and 13.1 mile run -- in place. The revised mix resulted in the rare situation where more than half the race took place on the run.

After a remarkable 24% DNS rate, and a 1% DNF rate, roughly 1250 athletes covered the revised course in an average time of 3 hours, 32 minutes. Our analysis of the 2012 results are presented below, with average times and splits by age group.

The course revision in 2012 presents the opportunity to tackle three bike and run questions compared to 2011 performance.

1. Bike: How much faster, in average miles per hour, would 2012's 13.69 mile ride be compared to 2011's full 56 mile distance? Answer: only about 10% faster, or about 1 mile per hour, on average. I would have expected faster speeds, even if riders faced extremely cold conditions.

2. Run: Having prepared to ride 56 miles, but instead riding far less, with presumably fresher legs, how much faster would average 13.1 mile run splits by in 2012? Answer: about 10 minutes on average. Much faster than I would have expected; especially the top 2 pros running sub-5:30/mile pace. 

3. Bike/Run Split Correlation: For many races, we correlate all finishers' bike and run splits to gauge how many triathletes rode too hard on the bike course, and ultimately paid for it with a painfully slow run, for example. At Boise, with a significantly shorter bike course with an average split of 42 minutes, would many athletes suffer on the run? Answer: not too many. Most raced steadily or even had energy to spare after conservative bike splits.

Finally, putting all the pieces together, here are the average swim, bike, run and transition splits for each age group. If you finished Ironman Boise 2012 in tough conditions, you have plenty to be proud of. If you beat these average splits, even more.

Ironman 70.3 Muncie 2012: Results Analysis (Shortened Course)

Due to expected extreme heat conditions on race day, organizers revised the usual Ironman 70.3 Muncie course to a distance of 1 mile swim, 30 mile bike and 3 mile run. After a 13% DNS rate, and a 2% DNF rate, nearly 1500 athletes covered the revised course in an average time of 3 hours, 6 minutes. Our analysis of the 2012 results are presented below, with average times and splits by age group.

The course revision in 2012 presents the opportunity to tackle the question: if the 2011 race were revised to 2012 distances, how would the results compare?  The surprising answer: 2011 results would have been faster. 


We took the complete 2011 splits and finish times by age group and adjusted them to equivalent distances of 1 mile swim, 30 mile bike, 3 mile run. If the 2011 race had been stopped at that point, the average finish time would have been 2:48, or about 11% faster. 

Here's further detail about 2012 results. For more, see our complete Stats/Analysis page with more than 200 articles examining racing and athlete performance from all the angles.