Podcast, Racing

The new Kona and 70.3 Worlds qualification system with Russ Cox | EP#467

 July 31, 2025

By  Bernardo Gonçalves

LISTEN TO THE EPISODE HERE:

Russ Cox - triathlon coach

Russ Cox is the man with the data when it comes to Kona and 70.3 Worlds qualification. In this episode we discuss the new qualification system announced by Ironman in July 2025, and the implications for athletes wanting to qualify.

HIGHLIGHTS AND KEY TOPICS:

  • A detailed view on the inner workings of the new qualification system work
  • How do the "Kona standard" and "70.3 standard" (coefficients for normalised age-graded times) work? 
  • Common misconceptions about the new system
  • Pros and cons of the new qualification system 
  • Fairness
  • Are there winners and losers with the new system? 
  • Implications of the new system for athletes wanting to qualify for Kona or 70.3 Worlds
  • Can you predict the time needed to qualify?
  • Optimising race selection under the new qualification system

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Shownotes

Russ' background

02:51 -

  • I am a triathlon coach with a long-standing commitment to collecting and analyzing performance data from Ironman and Ironman 70.3 races.
  • My focus lies in understanding the realities behind race outcomes—particularly regarding qualification standards and how they manifest in practice.
  • I began this work around 2012 as a side project to my coaching activities, driven by a curiosity about what Ironman performance truly looks like beyond the usual narratives and anecdotal accounts.
  • Rather than relying on generalized perceptions, I wanted to examine the data directly—identifying where athletes actually finish, analyzing average times, and determining what it truly takes to qualify.
  • Over the past 13 to 14 years, this analytical work has evolved into a key part of my professional approach. Many athletes and coaches have since relied on the insights available through my website, which I understand will also be linked in the show notes for reference.

Ironman and IM 70.3 qualification process differences

04:30 -

  • In both the previous and current qualification systems for Ironman and Ironman 70.3 races, each event offers a certain number of slots for age group athletes to qualify for their respective World Championships. However, the methodology for distributing those slots among the age groups has evolved.
  • Under the former system, slot allocation was determined by the number of athletes who started the race in each age group. This proportional method meant larger age groups received more slots.
  • The allocation followed a mathematical approach known as the D'Hondt method, originally designed for proportional representation in elections, which allowed for a relatively fair distribution across varied age group sizes.
  • For many years, slots were allocated collectively across all age groups, but more recently—especially after Ironman split the World Championships by gender—separate allocations for male and female athletes became more common, particularly in the 70.3 series.
  • The new system, by contrast, does not assign slots until the race concludes. It introduces a performance-based approach where finish times are normalized using a proprietary scale developed by Ironman.
  • This scale is based on historical finishing times from recent World Championship races and adjusts performances according to age and gender. For example, a male athlete in the 35–39 category will have his time adjusted differently than a male athlete in his 60s, to reflect the natural performance decline with age.
  • This method attempts to create a more equitable evaluation of athletic performance across categories, rather than simply using raw finish times that inherently favor younger athletes.
  • After normalization, slots are awarded based on ranking in this adjusted performance list. Each age group is guaranteed one slot, which is initially assigned to the winner but can roll down as far as third place. No further roll-down is allowed. The remaining slots are then distributed to the top-ranked athletes in the normalized results, regardless of age group.
  • Typically, there are about 14 to 16 age group categories per gender, ranging from 18–24 up to 90+. Not all older age groups are always represented, particularly in 70.3 events.
  • For example, in a recent 70.3 race with 30 male and 30 female slots, roughly 10 in each gender may be distributed to age group winners or podium finishers, with the remaining 20 slots awarded based on the normalized rankings.
  • A notable distinction remains between Ironman and Ironman 70.3. In 70.3 events, the number of slots is pre-divided equally by gender—e.g., 30 for men and 30 for women—meaning men compete only against men, and women against women.
  • In Ironman races, however, there is a single pool of slots (e.g., 40 total), and all athletes compete for qualification based on their performance within the normalized rankings, regardless of gender.
  • This performance-based approach in Ironman can lead to variable gender slot distribution depending on the relative strength of performances. For instance, if female athletes perform particularly well in a given race, they may secure a greater share of the total slots.
  • In practice, data shows that women typically receive around 25% of the available slots in Ironman events, though this proportion varies by region due to differences in participation rates.
  • In contrast, the 70.3 system maintains an equal slot count per gender by design, thanks to the separate race days introduced following the recent format changes.

How to calculate your virtual time

11:43 -

  • The final calculations under the new Ironman qualification system are, in essence, straightforward. Ironman has published the coefficients used to normalize finish times across age groups, and they have also explained the methodology behind them.
  • For Ironman races, the normalization is based exclusively on historical data from the Kona World Championship, while for Ironman 70.3 events, data from the 70.3 World Championships is used instead.
  • The calculation process involves identifying the top 20% of finishers within each age group at the respective World Championship events. From these athletes, Ironman computes an average finish time to represent the front-of-pack standard for that age group.
  • The fastest age group—typically males aged 30–34 or 35–39 for full Ironman events, and males aged 18–24 for 70.3—is used as the performance benchmark. The average times of the remaining age groups are then compared to this benchmark to determine a performance ratio or multiplier.
  • In Ironman races, a single set of coefficients is applied regardless of gender, whereas in 70.3 events, Ironman applies separate coefficients for men and women.
  • These coefficients are essentially scaling factors: the fastest age group receives a value of 1.00, meaning no adjustment is made. All other age groups receive a coefficient below 1.00, effectively reducing their finish times to account for age-related performance differences.
  • For example, a male athlete in the 50–54 category has a coefficient of approximately 0.902. If he finishes in exactly 10 hours, his normalized age-graded time becomes 9 hours and 1 minute. By contrast, a woman in the same age category has a coefficient of around 0.81.
  • If she also finishes in 10 hours, her adjusted time would be approximately 8 hours and 6 minutes. This adjustment attempts to equate performances across age groups by acknowledging physiological decline with age, thereby offering a more balanced and inclusive qualification framework.
  • Once these adjustments are applied across all finishers, a new ranking list is generated. This adjusted ranking can differ significantly from the actual finish order, as athletes from older age groups may move up the rankings due to more substantial time reductions, while younger age group athletes will see minimal or no adjustments.

Russ' comments on the callibration coefficients

16:12 -

  • I find the new Ironman qualification system to be a clever and thoughtful solution. It aligns closely with ideas I’ve considered myself, particularly around the challenge of comparing performances across different Ironman courses.
  • For example, comparing a 10-hour finish in Lanzarote to a 10-hour finish in Frankfurt doesn’t reflect the same level of difficulty, as the courses are vastly different. The normalization system addresses this issue to some extent by focusing on athlete performance rather than course-specific results.
  • In analyzing race performance data over the years, I’ve noticed that the impact of course variation is not uniform across the field. At the back of the pack, variables like course profile and weather tend to matter less; athletes here are often limited by their fitness levels and race preparation, not the marginal differences in terrain or temperature.
  • Conversely, among the front-end athletes—those aiming for qualification—subtle course differences can have a much more significant effect.
  • Therefore, a single normalization model cannot accurately capture performance variations for every participant, but when applied to the top percentiles, it can offer a fairly representative and useful comparison.
  • This normalization method relies on coefficients derived from the top 20% of finishers in each age group at the Kona World Championship (for Ironman) and the 70.3 World Championships.
  • These are not drawn from a single year, but from a rolling five-year dataset, which minimizes anomalies caused by small sample sizes or exceptional individual performances. The result is a more stable and consistent coefficient that adjusts finish times based on age group, offering a more balanced comparison.
  • It’s important to acknowledge, however, that no system will ever be universally accepted as fair. In any sport, there is always a degree of arbitration involved in setting qualification criteria, and triathlon is no different.
  • What Ironman has developed is not a perfect physiological model, nor is it intended to be. The coefficients do not represent a pure decline in athletic capability with age; they reflect a combination of physiological changes and real-world constraints that affect amateur athletes, such as financial resources, time availability, and life circumstances.
  • For instance, while the 18–24 age group is often the fastest in 70.3 events, Ironman’s top-performing age groups tend to be in the 30–39 range.
  • This is partly due to physiological maturity but also heavily influenced by life stage—athletes in their 30s often have the financial means and life stability to commit to the training, travel, and equipment Ironman requires.
  • By contrast, many high-performing athletes in the 18–24 range either turn professional early or step away from the sport due to other life priorities.
  • If the goal were to reflect physiological decline alone, one could simply take the single fastest time in each age group and use that as a benchmark. But this approach would risk overemphasizing outliers.
  • Perhaps a smaller sample, such as the top 5%, would better capture raw physiological trends. Still, that is not the apparent objective of Ironman’s model.
  • Instead, it aims to strike a practical balance between athletic performance, life context, and fairness in allocating World Championship slots.
  • From my perspective, this method is a significant improvement over the previous system, which was based solely on participant numbers and age group size. While no system will satisfy everyone, the new model reflects a more equitable and performance-driven approach to qualification.

Pros and cons of the new qualification system

26:14 -

  • One of the main drawbacks of the new Ironman qualification system is the increased uncertainty athletes face before race day. While you can know in advance how many total slots a race will offer, you have no way of knowing precisely how those slots will be distributed until the event is over.
  • Under the previous system, athletes could estimate their chances with reasonable confidence based on historical slot allocation by age group. Now, with the age-graded, performance-based model, that predictability is largely gone.
  • I've been experimenting with how this new system would have impacted past races by applying the new age-normalized model to historical data. The results highlight just how variable the new distribution can be.
  • In one 70.3 race, for example, the 40–44 male age group received only one slot—awarded to the winner—while the 35–39 group received nine. Under the old model, larger age groups like 40–44 were typically guaranteed several slots.
  • This new system breaks from that logic entirely, which may be unsettling for those accustomed to slot forecasts based on age group size.
  • This shift changes how athletes must approach the qualification process. It’s no longer enough to say, “My age group typically gets six slots, and I need to aim for a top-six finish.” Now, you’re competing in a broader performance pool, where your normalized, age-graded time determines whether you earn a slot.
  • This requires a change in mindset. Athletes need to assume that, unless they win their age group, qualification will depend on how their performance ranks in the overall adjusted field.
  • I've not yet conducted a full statistical analysis of how stable age-graded qualification times are across multiple years, but initial observations suggest there is considerable variability.
  • On my website, users can now input a finish time and age group for a specific race and see where that time would have ranked in previous years.
  • This tool illustrates how variable performance-based rankings can be, especially in races with rolling starts where athletes cannot directly compare positions during the race.
  • Despite this unpredictability, the model does emphasize the importance of being among the top performers overall. Rather than focusing on how many slots a specific age group receives, athletes now need to target a performance level that will place them among the best age-adjusted times across the entire field.
  • This may simplify race strategy in some respects—since the only secure path is to aim to be among the fastest in your cohort—but it also requires a broader awareness of competition beyond one’s own age group.
  • There is also a statistical case to be made that, over time, this system may offer more consistency. While you might previously have relied on a limited pool of five or six slots in your age group, and risked being edged out by a particularly fast group on race day, now you’re effectively competing for a share of a larger performance-based pool—perhaps 20 or 25 slots depending on the race.
  • That could, in theory, create more stable qualification thresholds from year to year, though more data is needed to confirm that trend.
  • Another consequence of this shift is that course selection becomes even more important. Since qualification now hinges on relative performance, athletes should prioritize choosing races where they can perform best.
  • The old strategy of selecting a race simply because it offered more slots to a particular age group becomes less relevant. Instead, I advise athletes to focus on courses that suit their physiological strengths—whether that means flatter, faster courses or those with more elevation or heat. That advice isn’t new, but it now carries greater weight.
  • Of course, exceptions still apply. Athletes who are particularly strong in extreme conditions—like heat or humidity—may still benefit from targeting races in regions such as Southeast Asia, where lower participation or challenging conditions can offer an advantage.
  • But generally, the shift toward a performance-based system pushes the focus back to the athlete’s ability on race day rather than on the slot math beforehand.

The impact of slower races on the qualification process

34:43 -

  • One area I’ve been reflecting on—particularly in relation to race selection—is the potential impact of course speed when it comes to qualification under the new system.
  • Since Ironman’s age-normalization coefficients are based exclusively on data from Kona, it raises the question of how races that are significantly slower or faster than Kona might influence qualification outcomes.
  • My hypothesis is that slower courses may benefit younger athletes, particularly those in the fastest absolute age groups, because differences in time tend to become more pronounced on challenging courses.
  • For example, a top-performing male in the 30–34 age group might finish Kona in eight hours, while a top 50–54 age grouper could be out there for over ten.
  • On a slower course like Ironman Wales, that difference could be amplified further—nine hours versus nearly twelve. This time spread could disadvantage older athletes whose performances, even when adjusted, remain proportionally further behind in raw time.
  • Conversely, faster courses tend to compress finish times, which could benefit older athletes by narrowing the performance gap and creating a more favorable normalized ranking.
  • While this is still speculative, it’s a concept I’m keen to investigate further. As I begin applying the new qualification model to past race results, I hope to identify patterns that confirm or challenge this theory.
  • It’s one of many aspects where course profile, athlete type, and age group might interact in unexpected ways under the new system.
  • Another point worth highlighting is that this shift in qualification mechanics coincides with a significant reduction in the total number of slots available for the Ironman World Championship.
  • For the past several years, the sport operated under a dual-World Championship format—one for men and one for women—which effectively doubled the available places, often offering 4,000 or more slots combined.
  • With the return to a single-day Kona event from 2026, that number has been halved, bringing us back to around 2,000 total participants.
  • Moreover, a portion of these remaining slots continues to be reserved for special categories, such as legacy athletes and charitable entries, which further reduces the number of performance-based age group slots.
  • Even under the old allocation model, we would now be seeing a considerable tightening of competition. It’s no longer realistic to expect that the largest age groups would receive ten or more slots in most races. At major qualifying races such as Ironman Texas, for instance, five or six slots for the top age group may now be the new norm.
  • In that sense, the increased difficulty in qualifying cannot be attributed solely to the introduction of the new system. The contraction in available slots is an equally important factor—one that adds further pressure and underscores the need for athletes to optimize every aspect of their preparation, race selection, and in-race execution.

Facilitating qualification to specific age groups compared to others

40:08 -

  • One important detail regarding the new Ironman qualification system is the use of a five-year rolling average to determine the age-normalization coefficients.
  • Each year, the oldest data point used in the current model will be dropped and replaced with the most recent World Championship results—Kona for Ironman and the 70.3 World Championships for Ironman 70.3.
  • For instance, the 2026 qualification cycle for 70.3 began in early July, and the Kona qualification cycle will follow around mid-to-late August. From 2027 onwards, this rolling update will gradually incorporate the performance data shaped by the new system.
  • A compelling theory I’ve seen—and one that I find quite plausible—is that small biases in the initial coefficients could lead to a long-term feedback loop. If one age group is slightly favored in the current coefficient model, it may become easier for athletes in that group to qualify.
  • Over time, this could draw in more lower-ranked qualifiers within that age group, effectively diluting the performance level of the top 20% cohort used to calculate future coefficients. As this happens, the average performance standard for that group could decline, which would then raise the coefficient and make it even easier to qualify.
  • Conversely, an initially disadvantaged group may shrink in size and become increasingly difficult to qualify from, since the top 20% would become more concentrated and drive the standard up further.
  • This dynamic could indeed create a widening gap between age groups, making some increasingly accessible while others grow progressively more exclusive. That said, it will take time for this pattern—if it occurs at all—to manifest, given the slow rate at which the rolling data set evolves. The system won’t begin to reflect these shifts meaningfully until the coefficients are updated with several years of new input.
  • It’s also worth considering the practical implications of roll-down slots, which remain part of the new system. Despite the performance-based model, there are still instances where qualification slots are awarded to athletes well outside the top ranks due to unclaimed or declined slots.
  • For example, at a recent 70.3 in Swansea, one category reached the point of calling out for any present and eligible finisher to accept a slot. This suggests that despite the effort to make qualification more performance-driven, there are still logistical gaps that allow for variability in who ultimately qualifies.
  • If adjustments are needed in the future, it may not be the overall framework that changes, but rather the specifics—such as narrowing the 20% performance window used for coefficient calculations. A narrower focus on top performers could mitigate some of the dilution effects described earlier.
  • Additionally, data from recent races already shows considerable fluctuation in how slots are distributed among age groups. In 70.3 events, for example, we’re seeing one race give nine slots to the 35–39 group, one to 40–44, and six to 45–49. This level of inconsistency contrasts sharply with the previous system, which, while imperfect, was more stable and predictable in its allocations.
  • There’s also a perception emerging that the current system may slightly favor older age groups. The normalized adjustments have, in some cases, allowed high-performing athletes in categories like 60–64 or 65–69 to move up into qualification ranks more easily.
  • This is likely a byproduct of the generous coefficient adjustments those age groups receive, allowing their strong relative performance to outweigh their raw finish time disadvantage.

The fairness of this rule for AGs

44:16 -

  • From what I’ve seen so far in the data, especially in 70.3 events like the one-day World Championship qualifier in Lahti, the outcomes are quite variable across age groups.
  • While certain patterns do emerge, like the consistent assignment of only one slot to the men’s 18–24 category in nearly every race, it’s difficult to draw sweeping conclusions about systemic favoritism without broader, long-term analysis.
  • It’s true that some older age groups appear to benefit more frequently under the new system, but I would caution against assuming this is universally the case. The structure of the 70.3 championship—with its separated men’s and women’s events and a higher number of available slots—creates a broader distribution, allowing for more diversity in which age groups receive multiple slots.
  • When applying the new model retroactively to older Ironman events, however, we observe just how constrained the slot counts have become. In many cases, a “large” age group may now receive only four or five slots, while others get just one or two. That’s a notable shift from the previous era, where top age groups in major qualifying races often received eight or more.
  • Gender distribution also continues to reflect broader historical patterns. While some expected the new system to significantly increase the number of slots awarded to women, the actual data suggests this hasn't happened on a large scale.
  • In many cases, women’s age groups still receive just one slot, occasionally two. The normalized system does allow more slots to be awarded when strong performances justify it, but it hasn’t created disproportionate representation.
  • From my perspective, we’re seeing female athletes receiving around 20–25% of the available slots, which is broadly consistent with participation rates—and not the major departure some critics feared.
  • It's also important to recognize that current slot allocations are still influenced by the legacy of the old system. The coefficients used to normalize performance are built from five years of World Championship data, and those events were not gender-equal in participation. If, over those years, men dominated start lists and finishing ranks, the top 20% used to determine the coefficients will reflect that.
  • This applies equally to gender and age group analysis: the standards we use now are built on a historical performance base that shaped who was qualifying then, and that inevitably influences who qualifies now. If the demographic balance of qualifiers changes over the next five years, the rolling average will eventually reflect that shift.
  • Regarding fairness, I do believe the new system marks a step forward. The old model essentially rewarded volume—whichever age groups had the highest participation rates received the most slots. While this was predictable, it didn’t necessarily reflect performance or equity.
  • The new approach, although more complex and less transparent before race day, is based on adjusted athletic performance and provides a more nuanced view of achievement. That said, it will never be perfect. Every system will have edge cases, outliers, and athletes who feel disadvantaged by the way qualification plays out in a given race.

Practical applications of this rule

50:14 -

  • As we consider the current Ironman qualification system, one of its underappreciated strengths is how it allows athletes to assess their chances with a reasonable degree of confidence—if they know where to look and how to interpret the data.
  • While predicting slot distribution before race day has become more complex due to the performance-based model, athletes can now evaluate their position using normalized age-graded rankings from past races.
  • On my website, athletes can input their finish times and age groups to view how they would have ranked across several years of race data. This includes not only their overall and age group rankings, but also their qualification ranking under the new system, as well as the percentile of finishers they would fall into.
  • For example, a time that ranks in the top 0.5% of all finishers at Ironman Wales indicates a level of performance that is exceptionally hard to achieve, even if it may be enough to qualify.
  • This functionality helps athletes determine whether qualification is realistic. If a user consistently ranks in the 200s, the answer is clear. But if they’re hovering around the 40–70 range in various races—depending on the slot count and event type—they're in the margin where qualification might be possible with targeted improvements. That’s where race selection and detailed planning become vital.
  • Athletes need to be realistic about the variability in course difficulty. A time achieved in Frankfurt cannot be directly compared to Wales, for example.
  • The website’s tools help with this by providing context, such as where a time would place you within the entire race field. If a 10:30 finish would put you in the top 1% at a given race, it may not be achievable for many, even if it meets the threshold for qualification.
  • Additionally, there are interactive features that let users test scenarios—for instance, how many slots would have been awarded based on either the old or new system, or how different allocation rules would affect qualification times. This is particularly useful when planning for future races where slot distributions are not yet confirmed.
  • Another valuable tool is the ability to view distribution charts of split times for athletes under certain finish thresholds. This allows for a more granular assessment of what kind of swim, bike, and run splits are typically required to hit a target finish time.
  • If, for instance, a target time requires a bike split that falls outside what the athlete is currently capable of—even within that finish group—it may not be realistic without significant improvement.
  • Beyond my site, Ironman’s own tracker also now displays age-graded rankings post-race for 70.3 events. This provides a quick way for athletes to see where the cutoff for qualification occurred in their age group. While it’s not as detailed as the custom filters available on my platform, it’s a useful complementary tool.
  • While the Ironman Tracker and post-race summaries offer a convenient way to see where the qualification cutoffs landed, especially for 70.3 events, they don't provide the depth of analysis needed for strategic planning.
  • That’s where the more advanced filtering and simulation tools on my website become invaluable. For instance, if you're aiming to qualify at a specific venue next year, you can analyze the last 20 years of results from that race, compare trends, and estimate what time might be required under current standards—factoring in normalization and slot distribution.
  • An important caveat in this process is the danger of misapplying times across courses. Athletes must be mindful that a time achieved on a fast, flat course like Barcelona will not directly translate to a course like Lanzarote or Wales.
  • The platform helps mitigate this by showing what your entered time would rank as in percentile terms and overall placement, allowing you to gauge whether that performance would actually be competitive on a different course.
  • From a coaching perspective, this enables a more realistic and informed conversation with athletes. If someone tells me they’re targeting a 10:30 finish at Lake Placid, I can use the filtering functions to look at only sub-10:30 results and analyze typical splits for athletes at that level.
  • This helps determine whether their goal is in line with their training and capabilities, or whether adjustments are needed. It also helps identify whether a specific goal time aligns with a high percentile ranking or a more attainable range.
  • The ability to test multiple course options, input different finish times, and adjust for hypothetical slot allocations makes this an exceptionally versatile resource. It supports athletes in making more intelligent decisions about which races to target based on where they are most competitive, rather than where they hope fewer strong competitors will show up.
  • And finally, for athletes who are close—but not quite in qualification territory—this type of analysis can help define what performance improvements are required.
  • It’s no longer a matter of simply choosing a “soft” race. Instead, the question becomes: where can I perform at my absolute best, and what do I need to do to ensure that my normalized ranking places me in the top tier of finishers? This shift in perspective is crucial under the new system.

Final thoughts about the new regulations

1:02:53 -

  • It’s still early days for the new Ironman qualification system, and its full impact will only become clear with time. While the 70.3 qualification cycle for 2026 has already been underway for several weeks—offering a growing set of results to analyze—the full-distance Ironman season using this system will officially begin in mid-August.
  • What adds complexity to this rollout is that some upcoming races are set to offer qualification slots for both the 2025 and 2026 World Championships. It remains unclear how Ironman plans to manage these overlapping slots—whether athletes will be allowed to choose which year they wish to qualify for, or whether allocation will be handled differently.
  • I would expect, based on past precedent, that most athletes would prefer to claim a Kona slot when given the option, but until the actual events take place, we won’t know exactly how these decisions will be administered.
  • As Ironman starts to apply the system across its full-distance events next month, we’ll begin to see how the performance-based model behaves at scale. With more data, trends will become clearer, and we’ll be better positioned to assess whether the system is

LINKS AND RESOURCES:


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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