Cardiorespiratory fitness has long been inversely associated with mortality, and has also been associated with reductions in cancer, diabetes, and coronary artery disease. However, some studies have found that intense exercise may be linked to cardiovascular problems. Note that these studies have often relied on questionnaires which may be subject to recall bias (when people have trouble remembering past events with accuracy).
In a 2018 retrospective cohort study, Cleveland Clinic researchers reviewed exercise treadmill stress tests for 122,007 adult patients seen from 1991-2014. They grouped patients into five fitness levels, from low (<25th percentile) to elite (≥97.7th percentile). They then pulled death records mostly from Social Security data and analyzed the association between fitness level and death.
The study authors confirmed that cardiorespiratory fitness was inversely associated with all-cause mortality. Adjusted mortality risk was highest in the least fit and exceeded other clinical risk factors like smoking and diabetes.
Ultimately, the more fit someone was, the less likely he or she was to die prematurely. This held true at every fitness level, with elite performance associated with an 80% reduction in mortality risk compared to those at the lowest fitness level.
In a follow-up CNN interview, Dr. Wael Jaber, the senior author, emphasized that
“being unfit…should be treated as a disease that has a prescription, which is called exercise”
Mandsager, K., Harb, S., Cremer, P., Phelan, D., Nissen, S. E., & Jaber, W. (2018). Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA network open, 1(6), e183605-e183605.
Photo by Victor Hanacek on picjumbo
