IRONMAN · Field strength

IRONMAN Cozumel 2025: the men's front got an hour faster

Same course, a similar day, and a very different race at the front of the men's age groups.

By Blame the Course · · 2 min read

1 h 39earlier: 10th place in M50-54, 2025 against 2024

1,409finishers in 2025, up from 1,016

+8.8%M50-54's 10th place against a typical IRONMAN, course and day taken out

Tenth place, an hour earlier

IRONMAN Cozumel's 2025 race counted for the 2026 Kona season, the first with age-graded slots. The field grew from 1,016 finishers to 1,409, and the front of the men's age groups changed out of all recognition. Tenth place in M50-54 came 1 hour 39 minutes earlier than the year before: 11:17 in 2024, 9:38 in 2025. In M45-49 it came an hour earlier (10:29 to 9:28), and in M35-39, 1 hour 15 minutes earlier.

A gap like that usually means the day was different: cooler, calmer, a current that helped the swim. Not this time.

It wasn't the weather

Both race days played within 1% of each other, measured from the athletes who raced Cozumel and other courses. With the course and the day taken out, the gap stays the same. In 2024, every men's age group at Cozumel was slower at 10th place than the same place at a typical IRONMAN. In 2025, all but the youngest were faster, the 40 to 64 groups by 6 to 9%. Only 21 IRONMAN race years since 2023 had a stronger front.

10th place in each men's age group, against the typical 10th place at an IRONMAN (course and day taken out)

−15%−10%−5%0%+5%+10%← slower than typicalfaster →M18-24−5.0%M25-29+0.8%M30-34+2.9%M35-39+4.9%M40-44+5.9%M45-49+7.6%M50-54+8.8%M55-59+7.2%M60-64+6.7%
20242025
Typical: the median 10th place of the same age group at every IRONMAN of 2023–26 with 20 or more finishers in it.

The women's fronts didn't follow: the change was in the men's race.

What it means if you race Cozumel

A finish that made the top ten in 2024 would have been well outside it in 2025. If you are choosing a race for a podium or a slot, last year's results at the same race are a better guide than its reputation, and the strength of its field matters as much as its course. Each race's field strength on this site compares the front, the top quarter and the middle of every age group with a typical race, the course taken out.

What Kona will tell

How hard Cozumel's slots were to win will show in the rolldown: Kona's results on 10 October show who took them, and the site works out where each athlete in Kona qualified.

Measured from IRONMAN's public results. Course and day speeds come from the athletes who raced more than one course; "typical" is the median of the same measure across races of the distance. Figures as of 3 October 2026. Blame the Course is independent and not affiliated with IRONMAN.

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