How Does She Run So Fast? Examining the Muscle Composition of a 91-Year-Old World Record Sprinter

Baltimore (April 25, 2025)—A woman smashed a longstanding world record in the 200-meter sprint at the age of 91, prompting scientists to delve into her physiology to learn how she can run so fast. Researchers will present their findings at the 2025 American Physiology Summit in Baltimore. The Summit is the flagship annual meeting of the American Physiological Society (APS).

Reduced mobility is a part of aging for most adults. Aerobic and strength exercises and balance training can help maintain mobility, independence and quality of life. Older adults who reach age 90 often are not active and healthy enough to participate in strenuous physical activities or competitive sports such as sprinting. The subject of a recent case study is the exception to this rule.

An Italian woman set a new world record in the 90-plus age category for the 200m sprint in May 2024 with a time of 51.47 seconds. This record was nearly 1.5 seconds faster than the previous world record. At age 91, she participated in a study called Trajector-AGE to better understand the physiology of her muscle.

The world record holder performed a cycling test and knee extensor exercises in the lab of Simone Porcelli, MD, PhD, at the University of Pavia in Italy. The goal of the exercise session was to assess power output and muscle fatigue. In addition, the researchers performed a muscle biopsy of the sprinter’s thigh and muscle fibers were analyzed in the lab of Christopher Sundberg, PhD, at Marquette University in Milwaukee.

The research team found that the world record holder’s cardiorespiratory fitness—the ability of the circulatory and respiratory systems to supply the muscles with oxygen during exercise—was comparable to highly fit women in their 50s. Mitochondrial function (the energy centers of the cells) was also indistinguishable from that of women decades younger.

The woman’s slow-twitch (Type I) muscle fibers were remarkably large. Slow-twitch fibers can work for a long time with minimal fatigue. Built for endurance such as walking, jogging and long-distance running, these muscle fibers generate less power than fast-twitch fibers but do not tire as easily. She also had a very high percentage of fast-twitch (Type II) muscle fibers, which generate a lot of power. Fast-twitch fibers are ideal for quick and explosive movements such as sprinting, jumping and lifting heavy weights.

“This unique combination likely contributed to her exceptional 200m sprint performance, allowing her to maintain both endurance and speed at an advanced age,” said Marta Colosio, PhD, postdoctoral fellow at Marquette University and first author of the study. “Lifelong exercise training can enable extraordinary performance and maintain high functional levels even into the ninth decade of life.”

However, the findings of this study emphasize the benefits of physical activity at any age, including older adults who have not been lifelong exercisers. “Exercise is a powerful tool for promoting healthy aging,” Colosio said.

NOTE TO JOURNALISTS: The American Physiology Summit will be held April 24–27, 2025, in Baltimore. To schedule an interview with the researchers, conference organizers or presenters, or to request abstract A-1564, “How Does She Run So Fast? The Physiological Basis for the Elite Performance of the New—Over 90 Years of Age—World Record Holder in the 200M Sprint: A Case Report,” contact APS Media Relations or call 301.634.7314. Find more highlights from the meeting in our Newsroom.

Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.