Study finds higher fitness in midlife tied to more years free of chronic disease and longer lifespan
WASHINGTON (April 22, 2026) — How fit you are in midlife may help determine not just how long you live, but how many of those years are spent in good health, according to a new study published today in the JACC, the flagship journal of the American College of Cardiology.
The study found that adults with higher levels of cardiorespiratory fitness in midlife lived longer lives, developed fewer chronic diseases and spent more years free from serious illness compared with those who were less fit.
Cardiorespiratory fitness—how well the heart and lungs supply oxygen during physical activity—is known to reduce the risk of heart disease and early death. This study extends prior research by showing that fitness also plays a meaningful role in healthy aging, defined as years lived without major chronic disease.
The findings indicate that higher fitness in midlife is strongly associated with later onset of chronic disease, lower overall disease burden and longer life expectancy. These benefits were observed in both men and women.
Researchers followed more than 24,500 men and women who were healthy through age 65 and tracked their health outcomes later in life using Medicare data. Fitness was measured earlier in adulthood using a treadmill test, and researchers examined the development of 11 major chronic conditions, including heart disease, diabetes, kidney disease and cancer.
Compared with people who had low fitness levels, those with high fitness in midlife experienced clear benefits later in life. On average, they developed chronic diseases at least 1.5 years later, had fewer total conditions and lived longer overall. These patterns were seen in both men and women and across different ages, body weights and smoking histories.
Importantly, the study emphasizes health span—not just lifespan—highlighting that fitness helps people live more of their lives in good health, not simply live longer with disease.
The findings also underscore the public health value of physical activity, as cardiorespiratory fitness can be improved through regular movement such as brisk walking, cycling or other aerobic exercise.
Researchers note that improving fitness during midlife may be a key strategy for promoting healthy aging and preserving quality of life later on, even with modest increases in physical activity.
Limitations of the study include its observational design, which does not allow researchers to establish causality, and the fact that participants were generally health‑conscious, which may limit broader generalizability.
The American College of Cardiology (ACC) is a global leader dedicated to transforming cardiovascular care and improving heart health for all. For more than 75 years, the ACC has empowered a community of over 60,000 cardiovascular professionals across more than 140 countries with cutting-edge education and advocacy, rigorous professional credentials, and trusted clinical guidance. From its world-class JACC Journals and NCDR registries to its Accreditation Services, global network of Chapters and Sections, and CardioSmart patient initiatives, the College is committed to creating a world where science, knowledge and innovation optimize patient care and outcomes. Learn more at www.ACC.org or connect on social media at @ACCinTouch.
The ACC’s JACC Journals rank among the top cardiovascular journals in the world for scientific impact. The flagship journal, the Journal of the American College of Cardiology ( JACC) — and specialty journals consisting of JACC: Advances, JACC: Asia, JACC: Basic to Translational Science, JACC: CardioOncology, JACC: Cardiovascular Imaging , JACC: Cardiovascular Interventions , JACC: Case Reports, JACC: Clinical Electrophysiology and JACC: Heart Failure — pride themselves on publishing the top peer-reviewed research on all aspects of cardiovascular disease. Learn more at JACC .org .
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Journal of the American College of Cardiology
Midlife Cardiorespiratory Fitness and Healthy Aging: An Observational Cohort Study
22-Apr-2026