A new study suggests that staying physically active throughout life may improve the body's ability to handle stress and illness as people age, possibly helping them live healthier, longer lives. Published in the journal GeroScience, the research explored the relationship between regular physical activity and a health measure known as "vitality capacity," which reflects how well the body can adapt and recover from stress as people grow older. The study involved about 40 participants in Nice, France, who were on average 64 years old. Half of them had been doing aerobic exercise, such as running or cycling, at least three times a week for over 30 years, accumulating at least 2.5 hours of moderate activity each week. The other half had minimal exercise, with no more than 75 minutes of physical activity per week. Researchers collected various health data from the participants, including heart rate patterns, muscle strength, blood markers, and lung function. This information was used to create a "vitality score," which helps assess the body’s ability to resist stress as it ages, also referred to as physiological reserve. While the study found no major differences between the two groups in areas like energy levels, metabolism, nerve and muscle function, grip strength, or inflammation markers, it did reveal some important distinctions in physiological reserve. One key finding was that the blood-oxygen saturation levels were higher in the physically active group, averaging 96.8 percent compared to 94.8 percent in the inactive group. The study also showed that vitality capacity tends to decline with age, but this decline was less pronounced in those who remained physically active. These results emphasize the significant connection between regular aerobic exercise and maintaining a strong physiological reserve, which could be important for healthy aging. The researchers noted that the study had limitations, such as its small size and the fact that most participants were healthy, older, and of white ethnicity. They emphasized the need for more research to confirm the usefulness of the "vitality score" in medical settings and to identify the most effective types and amounts of exercise for improving health outcomes.