How Lewis Hamilton’s “retired” off-sider landed in IndyCar

Cullen is one of New Zealand’s most high profile women in motorsport, thanks to her work with the seven-time F1 champion.

Cullen joined Hintsa Performance in 2015 and a year later became Hamilton’s off-sider in the wake of Aki Hintsa’s death.

While often labelled a physiotherapist or trainer, Cullen described herself as a “performance manager” in a role that’s more than just about the body.

“I’ve been working in high-performance sport probably for about 25 years now,” she told IndyCar.

“I started in athletics with 100- and 200-metre sprinters, the British Olympic team.

“I went to the Athens Olympics [in 2004] with them. We got a gold medal – the only time Britain had actually beat the USA or Jamaica.

“For me, coming into motorsport, most people who are involved here are about the cars whereas I’m about the driver and the performance of the driver.”

Cullen and Hamilton parted company at the end of 2023.

After nearly a year of radio silence, Cullen’s first public appearance came at IndyCar’s non-championship event at The Thermal Club.

Through a sponsorship tie-up she met fellow New Zealander Marcus Armstrong and shortly thereafter they began working together.

“When I left Formula 1, I thought I was moving away from motorsport,” she explained.

“I was retired actually, so I took a year off last year and then I connected with Marcus Armstrong and I just started working with him on mental skills and things in the background.

“We have very similar values. we’re very driven, we’re very competitive, and I was really excited when I met him that he was that same way.

“So that’s how we connected and and he said ‘Do you want to come to a race’ and I was like ‘Oh yeah, I’d love to’.”

Despite wanting to get away from motorsport, Cullen said IndyCar had her hooked quickly.

“IndyCar just hit me,” she said.

“It is so much fun. Therma; actually had no fans, which was incredible, and I still just fell in love with it.

“The racing is incredible, the drivers are incredible, I was overwhelmed by the expertise of everyone in the paddock – so I arrived and I haven’t left.”

Cullen said she and Armstrong are still getting to know each other and understanding how the other works.

“Like all great athletes, the thing that makes them difference is their focus and their dedication and their belief that they have this true purpose which is to be the best,” she said.

“You’ll find that across all sports they sacrifice everything for this one dream and it’s so inspiring to work with these people and help them achieve that.

“We’ve only been working together maybe three months, so the way I coach is very much about getting to know them as a person and then helping facilitate how I can help them.

“We’re probably still in the infancy stage sort of navigating how that’s going to work in the future.”