Triathlon · born 2008 · Czech Republic

Road toIronmanat 18

Sebastian Michael Holeksa. The youngest Czech ever to finish a race on an Ironman 70.3 course. In June 2027 he takes on the full distance in Klagenfurt.

Ironman Kärnten Klagenfurt · 13 June 2027

—

days

—

hours

—

minutes

—

seconds

Become a partner →Results and splits

Sebastian Holeksa on the run leg of the race

Czechman 20265:15:37

Years old in Klagenfurt

Age at his first attempt at the full distance.

0km

Race distance

3.8 km swim, 180 km bike, marathon.

Starts in four countries

Czechia, United Kingdom, Spain, Austria.

Entry in the Czech Record Register

Verified, not announced. 9 June 2026.

Evidence

Czech Record Register · 9 June 2026

The youngest Czech
to finish a race on an
Ironman 70.3 course

Agentura Dobrý denRegistered 9 June 2026Race 6 June 2026

Most young athletes offer ambition. Here there is a stamped certificate, an official result list and a time anyone can verify in ten seconds.

Verify in the register (in Czech) →

Czechman Triathlon 2026 · Ironman 70.3 format

Official time

5:15:37

6 June 2026 · Dolany u Pardubic, Czechia19th in the M18–24 category362nd overallOfficial result list →

He raced in the M18–24 category at seventeen. No one had completed a 70.3 course at that age before, so taking part required explicit consent from both the organisers and his legal guardians.

Swim29:351.9 km

Bike2:43:2190 km

Run1:55:2021.1 km

The blue bar matches the ratio of the splits. The link opens the official result list on irontime.cz.

The swim leg in the field · 771 classified finishers

In the swim he is in the top 8% of the field

Seventeen years old against a field where most athletes are ten or more years older. The median swim split was 36:59 — Sebastian was 7 minutes 24 seconds faster.

Swim29:3561st of 771 · top 8% of the field

1stfield median771st

Ranks and times come from the official result list on irontime.cz, linked above.

From the age of six to the full distance

A path, not a stunt

Every step stands on the one before it. The solid blue line is what can already be verified. The dashed part is the season he is entered for.

Around 2015

First time in the pool

At the age of six. Swimming is still the discipline where he holds an edge.

8 September 2024

First half marathon — Ostrava City Marathon

A serious injury three days later and emergency surgery on 11 September 2024.

8 February 2025

Mesa Half Marathon, USA

A half marathon in Arizona, five months after the surgery.

2025

Czechman Short — 9th place

Youth category (16–17). His first big start in the series he would return to a year later over twice the distance.

2026

Ocelácký triatlon — 3rd, juniors

A regional triathlon in Czechia. Time 1:10:59, 19th overall.

6 June 2026

Czechman 2026 — 5:15:37

A half Ironman distance at seventeen. 1.9 km swim, 90 km bike, half marathon.

Sebastian Holeksa at the Czechman 2026 finisher wall

9 June 2026

Entry in the Czech Record Register

The youngest Czech to finish a race on an Ironman 70.3 course.

August 2026

Guest on Czech Radio Ostrava

February 2027

Training camp, Arizona

March 2027

Training camp, Mallorca

24 April 2027

TCS London Marathon

A two-day race for the first time, around 100,000 runners.

8 May 2027

Ironman 70.3 Alcúdia Mallorca

13 June 2027

Ironman Kärnten Klagenfurt

The first full distance. 3.8 km swim, 180 km bike, marathon — 226.3 km in total.

August 2027

Beskydská sedmička

A mountain endurance race in the Czech Beskids. The close of the season.

Solid line — verifiableDashed marker — enteredBlue — record and goal

Four starts, four countries, seven weeks

Season 2027

USAFebruaryMallorcaMarchLondon24 AprMallorca8 MayKlagenfurt13 JunBeskydyAugust

Seven weeks · three big races

Two camps, four starts, four countries. This is how far a logo on the race suit travels in one season.Diamond — race · Ring — training camp · Dashed — inbound from Arizona

24 April 2027

TCS London Marathon

42.2 km. Around 100,000 runners, a two-day race for the first time.

Entry confirmed—

8 May 2027

Ironman 70.3 Alcúdia

113 km. The dress rehearsal for the full distance, two weeks after London.

Entry confirmed—

13 June 2027 · season goal

Ironman Kärnten Klagenfurt

226.3 km. The first full distance and an attempt at another entry in the Czech Record Register.

Entry confirmed—

Late August 2027

Beskydská sedmička

A mountain endurance race. The close of the season at home.

Entry confirmeddate set by the organiser

Coverage

Media

August 2026Czech Radio Ostrava — studio guestListen (in Czech) →9 June 2026Czech Record Register — entryVerify (in Czech) →6 June 2026Czechman 2026 — official result listOpen →

Season 2027

For partners

A logo on a race suit that travels through four countries in seven weeks. And one historic attempt you can back before it happens.

Four starts in four countries, two training camps, seven weeks. Season map →

Tier 01Product partnerKit and materials genuinely tested in training and in racing.

Tier 02Supporting partnerLogo on the race suit all season, content from training and race weeks.

Tier 03Performance partnerCategory exclusivity, photo and video with usage rights, reports after key milestones.

Tier 04Title story partnerThe “Road to Ironman at 18 presented by…” position across the whole season.

01Logo on the race suit — four starts in four countries

02Named in interviews and press materials

03Content from both training camps and race weeks

04Photo and video with usage rights

05Product feedback from real racing conditions

06Discount or tracking code

Dossier CZ — PDF ↓Dossier EN — PDF ↓

No fixed rate card. Every package is built to fit.

Road toIronmanat 18

The youngest Czechto finish a race on anIronman 70.3 course

Official time

In the swim he is in the top 8% of the field

A path, not a stunt

Season 2027

Media

For partners

Let’s get to work

The youngest Czech
to finish a race on an
Ironman 70.3 course