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Marta’s story: Retirement to global marathon runner

A marathon runner wearing a Tokyo Marathon 2024 t-shirt and multiple race medals stands in front of a window overlooking a city skyline.

A retired schoolteacher from the Greater Houston area will complete the World Marathon Majors to help fund cancer prevention research.

Author: Katie Horsfall
Published: 27 March 2026

Marta Mixa is running the iconic TCS London Marathon for World Cancer Research Fund – earning all six stars from the original Abbot World Marathon Majors series (the world’s most prestigious long-distance running events).

Born in San Salvador and a US citizen for 40 years, Marta began her six-star journey back in 2019 with the New York City Marathon. After qualifying Boston and Chicago and running Berlin in the same year, Marta went on to complete three World Marathon Majors in 2022 alone.

A smiling marathon runner in a Boston 2022 vest, sunglasses, and cap raises her arms in celebration, flashing a peace sign as she nears the finish line, with spectators behind a metal barrier.

In 2024, she crossed the finish line once more, completing the Tokyo Marathon and bringing herself one step closer to the iconic medal. Now more determined than ever to conquer the programme, Marta registered for the TCS London Marathon in a bid to earn her sixth and final star.

A smiling marathon runner wearing sunglasses, a cap, and a colourful outfit holds up a finisher's medal. Other runners and trees are visible in the background. The runner's bib reads 77579 and 東京メトロ (Tokyo Metro).

Fundraising for cancer prevention research is important to Marta after losing her aunt to breast cancer in 2024. Marta shared:

“She fought until the very end, but cancer stole her life, leaving three children, grandchildren, and her great grandchildren behind. It was really hard because she was the first family member that ever passed away from cancer.”

Marta’s sister-in-law, Sue, was also diagnosed with cancer in another devastating blow for the family.

“Sue was a vivacious, strong woman who loved the great outdoors and lit up every room. She fought for six long years and it was hard to see her go.”

Driven by her loss, Marta committed herself to not only support cancer research but to embracing a healthier lifestyle – which is proven by science to reduce risk of cancer along with many other conditions.

A smiling marathon runner in blue kit stands on a sunlit road holding a medal, with other participants and spectators walking behind her. She wears sunglasses, a headband, and race number J38227.

Marta’s love of running began in her late 30s, and over the past six years, she has completed 15 marathons. She credits her strength and endurance in her 60s to a balanced, nutrient-rich diet. Marta explained:

“The right protein is so important, together with carbohydrates. Carbs give you energy, and protein keeps you strong. I try to incorporate lots of fruit and vegetables into my diet, as well as lean protein such as salmon and chicken.”

A woman with her arms raised runs in a marathon, wearing a white vest, pink visor, and pink knee-high socks. Other runners are visible behind her on a road lined with trees and flags.

Steve Greenberg, World Cancer Research Fund’s UK Director, commented:

“Marta is an unstoppable force, and her dedication to funding life-changing research is truly inspirational. Her active lifestyle and balanced diet echos our Cancer Prevention Recommendations, which help people live longer, healthier, and happier lives free from the devastating effects of cancer. She embodies everything that World Cancer Research Fund is about, and we are truly grateful for her support.”

For Marta, the journey has always been about more than medals:

“My motivation is letting others know they can do it too. Your age doesn’t matter. Stay strong, stay fit, stay healthy. Your body will thank you for it.”