Adults with higher cardiorespiratory fitness in their 40s and 50s went on to spend more of their later life without serious illness, according to a cohort study of more than 24,500 people published April 22, 2026 in the Journal of the American College of Cardiology. On average, the fittest group developed chronic conditions at least 1.5 years later than the least fit group.
The gap was not only in years. Among men, the high-fitness group experienced roughly 9% fewer chronic diseases and a 3% longer lifespan than low-fit men, with similar patterns in women. Researchers examined 11 major chronic conditions, including heart disease, type 2 diabetes, kidney disease and cancer.
How the study was done
The team drew on the Cooper Center Longitudinal Study, using a maximal treadmill test to estimate each participant's cardiorespiratory fitness earlier in adulthood, then followed their health through Medicare claims after age 65. Because the design is observational, it cannot prove that fitness itself caused the longer disease-free stretch, only that the two are strongly linked.
"The findings are very much in line with decades of research showing that cardiorespiratory fitness is one of the strongest markers of long-term health," Robert Glatter, MD, an emergency medicine physician at Lenox Hill Hospital in New York, told Healthline. He added that the study "does not prove cause and effect" and that fitter people may also have healthier diets or better access to care.
Also read: 8 warning signs of stomach cancer most people mistake for indigestion
What cardiorespiratory fitness actually means
Cardiorespiratory fitness describes how efficiently the heart, lungs and circulation deliver oxygen to working muscles. It is often expressed as VO2 max, the maximum volume of oxygen the body can use per minute. Higher values tend to track with lower rates of cardiovascular disease and early death, and they generally decline with age unless training offsets the drop.
The good news for people in their late 40s or 50s is that fitness is not fixed. Even moderate improvements shifted health outcomes in the new analysis, and the researchers frame midlife as a practical window to build what they call health span, the years lived without major disease.
What that looks like in practice
For most adults, that means aiming for at least 150 minutes a week of moderate aerobic activity such as brisk walking or cycling, or 75 minutes of vigorous activity, plus strength work twice a week, according to Glatter.
Cardiologist Cheng-Han Chen, MD, of MemorialCare Saddleback Medical Center, suggested a gentler on-ramp for people starting out. "I would encourage people to do at least 20-30 minutes of moderate-intensity aerobic activity, such as brisk walking, on most days of the week. As their fitness increases, they can then increase either the length or intensity of the exercise," he said.
Also read: If you take antibiotics, these common foods may make them less effective
The effect does not require becoming an athlete. "Even modest increases in cardiovascular fitness can lead to a 10-25% improvement in survival," New York cardiologist Mary Greene, MD, told Healthline. That aligns with earlier work suggesting that grip strength and walking speed also outperform many traditional risk markers as predictors of how long people live in good health.
If you are 40 or older and have been sedentary, or have a heart condition, check in with your doctor before ramping up intensity.
Also read: 8 warning signs of an overactive thyroid most people blame on stress
This article is made and published by Jesper Bengtson, who may have used AI in the preparation.