Ariarne Titmus had the world at her feet. So why did she walk away?

In October 2025, Olympic champion Ariarne Titmus shocked fans with a seemingly out-of-the-blue social media announcement that she was quitting competitive swimming at the tender age of 25.

Despite being at the peak of her powers, “the Terminator” wouldn’t be going to LA in 2028 to compete in a third Olympics; her Australian Dolphins days were over. She was calling time. The post included a telling letter penned by adult “Arnie” to her seven-year-old self. “The dreams you had … they all came true,” she wrote. “The pursuit was unrelenting and you gave it every skerrick of yourself.”

Relentless fills in the backstory to that momentous decision including how Titmus consulted tennis star Ash Barty, who three years before had also chosen to leave at the top of her game aged 25. Barty talked to her about the punishing tennis regime incompatible with “a stable family life” that had influenced her own decision. She also noted: “You’d rather people ask why you are retiring, not when you are retiring”. Those words struck a chord with Titmus.

In her attribution at the front of the book, jockey Michelle Payne describes this memoir as “a masterclass in resilience” and she’s spot on. Fuelled with plucky “underdog pride”, Titmus developed what she calls an impenetrable self-belief. She knew that with a lot of hard graft she had the talent to succeed.

The prologue transports us to the thick of Titmus’s breakout Olympic upset. It’s Tokyo and the 400 freestyle final. Thanks to COVID restrictions the stands are practically empty, but on the page the reader is poolside. “I’m here at my maiden Olympics, up against a genuine GOAT”, writes Titmus, “it felt unbelievable”. That GOAT is US superstar Katie Ledecky, a central character in Titmus’s life, and even though we know exactly what happens next – more than two million Australians tuned in to watch the race – there’s a nail-biting tension to the storytelling.

We are then taken back to where it all began: the family home in Tasmania, swimming lessons in school PE classes. Though competitive and eager, Titmus claims she wasn’t “gifted” as a child swimmer and certainly not a prodigy like Ian Thorpe, but she had something. She had to work harder than the rest and success involved “a relentless disciplined pursuit of goals” – hence the book’s title.

The narrative is honest and unfettered with the monotonous rhythm of an elite athlete’s life laid bare. Tales of punishing training sessions, early mornings in the cold, long hours in the pool and a necessity to forgo the usual rites of teenage passage – parties, drinking, socialising – reveal the rigour and fabric of Titmus’s daily ritual, year in year out.

Her passion is palpable, so is her exhaustion. The family relocates to Queensland to give her the best chance of success. Driving her hard from age 15 is controversial coach Dean Boxall, who uses all manner of devious and sometimes downright deceptive means to achieve their joint goals. There’s no question that Titmus believes she couldn’t have won her 33 international medals including four Olympic golds without Boxall’s uncompromising training methods. She is quick to defend his flamboyant celebration of her Tokyo win which went viral and was criticised by some for stealing the limelight from her moment of glory. “Bullshit”, she cries, arguing such people have no understanding of what it takes to become an Olympic champion.

At times, it does feel as if we are on that relentless treadmill with our intense duo, and while the race descriptions provide welcome drama, most affecting is the personal detail. The invasive minutiae, for instance, that doping testing involves and the anguish when doctors discover a growth on Titmus’s ovary. “It hit me like a train,” she says. It was then, for the first time, that she starts to look beyond her swimming career to a future in which she now fears her fertility could be compromised, and we gain an understanding of why this extraordinary athlete ultimately decided to embrace a new life out of the pool.

Relentless by Ariarne Titmus with Phil Lutton is published by Allen & Unwin ($35).

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