The critical role of cardiorespiratory fitness in disease prevention.

Cardiorespiratory fitness (CRF) has been increasingly recognized in recent years as an important predictor of risk for adverse outcomes in numerous chronic conditions. In fact, a growing body of epidemiological and clinical evidence demonstrates that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, hyperlipidemia, and type 2 diabetes. Moreover, adding CRF to these traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The utility of CRF now extends far beyond all-cause and cardiovascular mortality to include the prevention and treatment of numerous other chronic conditions; CRF has been demonstrated to have a mitigating influence in as many as 40 such conditions. Herein we discuss the impact of CRF in the prevention of chronic disease in both adults and children. This discussion includes recent data on interactions between CRF and aging, obesity, statin use, incidence of diabetes, and the impact of CRF and physical activity patterns in adolescents including mental health, scholastic achievement, and cardiometabolic health. Finally, we discuss how CRF, as an essential vital sign, can be implemented in clinical practice.