From IndyCar to Maranello: Marcus Armstrong explains why Angela Cullen is Lewis Hamilton’s ultimate secret weapon. How Lewis Hamilton's former physiotherapist Angela Cullen transformed his training and mental approach.

IndyCar driver Marcus Armstrong has opened up about the significant influence that Angela Cullen, the renowned physiotherapist and trainer of seven-time Formula 1 champion Lewis Hamilton, had on his racing career during her two-year sabbatical from F1. Angela Cullen, who spent seven highly successful years with Lewis Hamilton and the Mercedes-AMG Petronas team from 2016 to 2022, took a break to pursue other professional opportunities, later linking up with Armstrong during his rookie season in IndyCar with Chip Ganassi Racing.

Before the start of the 2023 F1 season, Lewis Hamilton announced that Angela Cullen would no longer be working alongside him, explaining that she was leaving to pursue her personal ambitions. While the exact reasons were not publicly detailed, her departure created a unique opportunity for Marcus Armstrong, who was then transitioning into top-tier American open-wheel racing. Shortly after, a shared sponsor facilitated a professional partnership between Cullen and Armstrong, allowing her to focus on the mental and physical aspects of the young Kiwi driver’s training regimen.

During a recent appearance on the ‘Quadcast’ podcast, released on Wednesday, December 17, Marcus Armstrong spoke in detail about his time with Angela Cullen. He revealed how her guidance helped him develop mental discipline and maintain focus amidst the distractions of professional motorsport. Armstrong emphasized that Cullen’s approach was highly structured, prioritizing activities that directly contributed to on-track performance and eliminating those that didn’t. He explained that her philosophy was simple: if it didn’t improve lap times, it wasn’t worth doing.

Even after Angela Cullen returned to Formula 1 to rejoin Lewis Hamilton for his new journey with Ferrari, Marcus Armstrong maintained a close professional and personal relationship with her. He credited Cullen for the significant leap in his 2025 IndyCar performance, which saw him achieve his best season yet. After joining Meyer Shank Racing, bolstered by a technical partnership with Chip Ganassi Racing, Armstrong secured 11 Top 10 finishes in 17 races, including two Top 5 results and a podium in Race 2 of the Iowa doubleheader. On the podcast, Armstrong noted that Cullen’s guidance instilled a new level of discipline, accountability, and focus that directly translated into stronger results on track.

Marcus Armstrong highlighted that while Angela Cullen had returned to F1 with Lewis Hamilton, their connection remained strong. He credited her influence as a key factor in his ability to deliver consistent and high-level performances in his first full season with Meyer Shank Racing. “She went back with Lewis this year, but we’re still very close, and I was fortunate to have that experience. I feel like that’s why I was able to make such a big step forward this season. You really have to earn your results; you can’t just expect them,” Armstrong reflected.

Recognizing his rising talent and consistent performance, Meyer Shank Racing extended Marcus Armstrong’s contract in mid-August, ensuring he continues to drive the No. 66 Honda through the 2026 season. With the continued support of mentors like Angela Cullen and the backing of a top-tier team, Armstrong is poised to remain a standout competitor in the IndyCar series while closely following the career developments of Lewis Hamilton and Ferrari in Formula 1.