Relevance of Fitness to Mortality Risk in Men Receiving Contemporary Medical Care

Background: An inverse association between cardiorespiratory fitness and mortality was robustly demonstrated 3 decades ago.

Objectives: The purpose of this study was to determine whether significant advances in disease prevention, detection, and treatment since that time have modified this association.

Methods: A total of 47,862 men completed baseline examinations, including a maximal treadmill test. Cohort 1 (n = 24,475) was examined during 1971 to 1991 and followed for mortality through 1992. Cohort 2 (n = 23,387) was examined during 1992 to 2013 with follow-up through 2014. Men were categorized as low fit, moderate fit, or high fit using Cooper Clinic normative data. Hazard ratios (HRs) for all-cause, cardiovascular disease, and cancer mortality were determined across fitness categories in the 2 cohorts.

Results: A significant inverse trend between fitness categories and all-cause (HR: 1.0, 0.60, and 0.53 in cohort 1 and HR: 1.0, 0.76, and 0.52 in cohort 2) and cardiovascular disease mortality (HR: 1.0, 0.55, and 0.43 in cohort 1 and HR: 1.0, 0.84, and 0.52 in cohort 2) was observed (p trend <0.001 for all). The trend across fitness categories and cancer mortality was significant for cohort 1 (HR: 1.0, 0.62, and 0.48; p < 0.001), but not for cohort 2 (HR: 1.0, 1.08, and 0.74; p = 0.19). HRs for all-cause mortality were 0.86 (95% confidence interval: 0.82 to 0.90) and 0.87 (95% confidence interval: 0.83 to 0.91) per 1-MET increment in fitness for cohorts 1 and 2, respectively (p < 0.001 for both). Similar values were seen for cardiovascular disease and cancer mortality.

Conclusions: Despite significant advances in disease prevention, detection, and treatment since fitness was first shown to be associated with mortality, the inverse association between fitness and mortality remains consistent in a contemporary cohort of men.