Association of Cardiorespiratory Fitness With Long-Term Mortality Among Adults Undergoing Exercise Treadmill Testing
In a study of over 122,000 adults, higher fitness kept lowering death risk with no ceiling, the fittest group had the lowest mortality of any group measured.
KEY FINDINGS
This cohort study, led by Kyle Mandsager and colleagues at the Cleveland Clinic Foundation in the United States, followed 122,007 adults who underwent exercise treadmill testing between 1991 and 2014. Patients were grouped into cardiorespiratory fitness performance categories relative to age and sex norms, then tracked for all-cause mortality. It was published in JAMA Network Open in October 2018 and remains one of the largest studies of its kind.
Cardiorespiratory fitness was inversely associated with all-cause mortality, and unlike many risk factors, the benefit had no observed ceiling. Adults with extreme fitness, two or more standard deviations above the mean for their age and sex, had the lowest risk-adjusted mortality of any group in the study, including those with merely above-average fitness.
Notably, the increase in mortality risk associated with low fitness was comparable to, or greater than, traditional risk factors such as coronary artery disease, smoking and diabetes.
This is a US-based study rather than an Australian one, but it remains among the most robust pieces of evidence available on fitness and survival.
The takeaway is simple. Fitness is not a cosmetic measure, it behaves like one of the strongest survival signals we can put a number on, and the fittest people in the study outlived every other group in it.
What gives that weight is the scale and reach of the evidence: a very large group tracked over two decades, with the benefit holding well beyond the young and healthy. It is the reasoning behind treating a measured VO2 max as a genuine longevity marker rather than a performance statistic.
