What It Takes to Make Kona’s Ironman World Championship a Success

Beginnings: Diana Bertsch now oversees the very races she once watched from the sidelines. She says her journey from passionate spectator to event leader speaks to her love of the Ironman triathlon and what it stands for.

In 1990, Bertsch was vacationing on Hawai‘i Island. On the final day of her stay, she woke early and made her way to the Kailua-Kona seawall to watch as Ironman contestants splashed into the ocean on the first leg of the grueling three-part competition. And she promised herself, “I’m going to do this one day.”

Two years later, she moved to the island to work on that goal.

“I’d always been so passionate about Ironman and just how it changes lives and how this community … gives to make this event possible.”

She volunteered for the event in all kinds of capacities for three years, then participated in a qualifying race, where she earned a coveted spot in the Ironman World Championship.

A few years later, she joined the Ironman organization, at the urging of its race director. Then in 2003, after three years working for Kona resorts, she became the Ironman race director herself. Today, she’s the Ironman’s senior VP of world championship events.

“Each year, we’ve worked to be better than the year before, to grow the success of the event, and to continue expanding on what’s made us our most successful. And that all starts with the foundation of who we are – Hawai‘i,” Bertsch says. “It starts with our culture and the people who have always believed in the event to make it possible.”

Lucy Charles-Barclay won the 2023 Ironman Championship in Kona. Below, the finish line in Kailua-Kona | Photo courtesy: Ironman

Then and Now: The event began on O‘ahu in 1978 with just 15 athletes; it moved to Kona in 1981. In a typical year, 94,000 athletes from around the world participate in Ironman World Championship qualifying events. The organization manages 40 such events worldwide.

Since 2023, the annual Ironman World Championship competitions for men and women have been held separately: in Kona during October and Nice, France, during September. Last year, the men competed in Kona; this year, it’s the women’s turn in Kona. Organizers expect the 2025 Kona triathlon will have 2,500 competitors, 5,500 volunteers and 11,000 spectators, in addition to exhibitors, medical support, media members and staff.

Men and women follow the same three-part course in Kona: a 2.4-mile swim, 112-mile bike course and 26.2-mile marathon.

“The spirit of Ironman is the spirit of Hawai‘i,” says Bertsch. “To me, it’s about never losing sight of the beauty of what Hawai‘i has given us – the culture and everything that’s come with it. The most important thing we can do when we plan a new year is never forget where we came from.”

The start of the triathlon: the 2.4-mile ocean swim | Photo courtesy: Ironman

Fulfillment: “I thrive on planning, execution and attention to detail. When everything comes together with the team, that’s where the reward lies. Events are stressful, but incredibly rewarding,” she says.

“I have the greatest team in the world, and we have this incredible community that supports us. Our 5,000-plus volunteers play a critical role in making it all happen.”