What We’re Seeing in the New IRONMAN Allocation System

As of 23rd of October 2025

How the New System Works

IRONMAN’s new allocation model combines automatic Age Group winner slots with performance-based slots, which are awarded using a “Kona Standard” that equalises results across age groups and genders.

For full details of the methodology, see the IRONMAN website.

Participation: 2024 vs 2025

Across the races we analysed, women’s participation dropped slightly in absolute terms but remained mostly flat as a share of the overall field.

Race	Women 2024	Overall 2024	% Women 2024	Women 2025	Overall 2025	% Women 2025	Change (pp)
IRONMAN Sweden	340	1,821	18.7%	401	2,023	19.8%	+1.1
IRONMAN Copenhagen	357	2,368	15.1%	449	2,447	18.4%	+3.3
IRONMAN Tallinn	131	710	18.5%	175	1,088	16.1%	−2.4
IRONMAN Switzerland	164	1,291	12.7%	222	1,449	15.3%	+2.6
IRONMAN Wisconsin	267	1,198	22.3%	285	1,317	21.6%	−0.7
IRONMAN Japan	142	1,310	10.8%	94	1,044	9.0%	−1.8
IRONMAN Maryland	262	1,058	24.8%	221	1,151	19.2%	−5.6
IRONMAN Italy	299	2,235	13.4%	273	2,219	12.3%	−1.1
IRONMAN Wales	152	1,634	9.3%	166	1,652	10.1%	+0.8
IRONMAN Gurye Korea	66	521	12.7%	97	893	10.9%	−1.8
IRONMAN Chattanooga	404	1,631	24.8%	297	1,342	22.1%	−2.7
IRONMAN Barcelona	374	2,729	13.7%	333	2,430	13.7%	0.0
IRONMAN Portugal – Cascais	159	1,188	13.4%	134	1,393	9.6%	−3.8
IRONMAN California	562	2,431	23.1%	445	2,314	19.2%	−3.9
Total (14 races)	3,679	22,125	16.6%	3,592	22,762	15.8%	−0.8

Key points:

• Women’s starters: –87 (3,679 → 3,592)(a small absolute decline across all events)

• Overall starters: +637 (22,125 → 22,762)(fields grew overall, so women’s proportional share fell slightly)

• Women’s share: ↓ 0.8 pp (16.6 % → 15.8 %)

• Strongest growth: Copenhagen (+3.3 pp) and Switzerland (+2.6 pp)

• Largest declines: Maryland (–5.6 pp) and California (–3.9 pp)

How World Championship Slots Were Distributed

Across these 14 races, 620 slots were available. The table below shows how the automatic slots were distributed.

Category	Women	Men	Total
AG Winner Slots	138	162	300
Performance Slots	15	305	320
Total Slots	153	467	620

In total, 24.7% of slots have been awarded to women

AG winner slots were relatively balanced (46% to women, 54% to men).

Performance slots were overwhelmingly awarded to men (95+%).

Performance based slots vs participation-based

We compared actual allocations with a model where slots were distributed based on the previous participation model (“participation slots”).

Race	Performance-based Slots (Women)	Participation-based Slots (Women)	Difference
IRONMAN Sweden	11	10	+1
IRONMAN Copenhagen	15	11	+4
IRONMAN Tallinn	11	10	+1
IRONMAN Switzerland	10	9	+1
IRONMAN Wisconsin	11	12	−1
IRONMAN Japan	12	10	+2
IRONMAN Maryland	10	14	−4
IRONMAN Italy	10	9	+1
IRONMAN Wales	9	9	0
IRONMAN Gurye Korea	10	10	0
IRONMAN Chattanooga	12	15	−3
IRONMAN Barcelona (new)	9	11	−2
IRONMAN Portugal – Cascais (new)	11	9	+2
IRONMAN California (new)	12	15	−3
Total (14 races)	153	154	−1

What this shows:

• Overall, women ended up with almost the same number of slots as they would under a participation model (153 vs 154).

Conclusions

• Women’s fields remain proportionally small, with only 15.8% of starters across the 14 full-distance IRONMAN races analysed. This represents a slight decline from 16.6% in 2024, showing that overall participation levels for women have stayed largely flat, still well below one in five athletes.

  
  

• Slot allocation under the new system is broadly aligned with participation-based outcomes. Women received 24.7% of total World Championship slots, compared with 24.8% under a purely participation-based model — essentially neutral at the aggregate level.

  
  

• Race-by-race results vary significantly: events such as Copenhagen, Japan, and Portugal awarded women more slots than proportional models would predict, while Maryland, California, and Chattanooga allocated fewer.

  
  

• Overall, the new methodology has not yet produced a measurable performance advantage for women on aggregate, though it has improved representation in some races with historically smaller women’s fields.

Response from IRONMAN:

“We’ve been monitoring the data on our side as well, and while we are only a few races in, we absolutely share the same early concerns. We plan to bring this to the committee for discussion after Kona, as while the current system is tracking slightly better than proportional slot allocation, it’s still not where we want it to be given how the performance pool is playing out.

We want to give the committee the opportunity to review and advise before making any changes to the process, though we’ve already started conversations internally. We’re grateful for the input of committee members and are committed to getting this right.”

We’ll continue monitoring race-by-race data as the season unfolds and share further analysis later this year. For the full results used, see our dataset here.

About Women in Tri UK

Women in Tri UK is a registered charity dedicated to breaking down barriers for women in swim, bike, run, and triathlon. Through our research, advocacy, and community programmes, we champion gender equality and inclusion across all levels of the sport — from grassroots participation to world-championship representation.

Our work on data transparency and equitable slot allocation is part of a wider mission to make triathlon a fairer and more accessible space for every woman who dreams of racing.

If you’d like to support our advocacy, community programmes, and research, you can donate to Women in Tri UK here. Every contribution helps us continue pushing for equity, representation, and opportunity for women in triathlon.