Life's Essential 8 Cardiovascular Health Score and Cardiorespiratory Fitness in the Community

Background The relation of cardiorespiratory fitness (CRF) to lifestyle behaviors and factors linked with cardiovascular health remains unclear. We aimed to understand how the American Heart Association's Life's Essential 8 (LE8) score (and its changes over time) relate to CRF and complementary exercise measures in community‐dwelling adults. Methods and Results Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise testing for direct quantification of peak oxygen uptake (V̇O 2 ). A 100‐point LE8 score was constructed as the average across 8 factors: diet, physical activity, nicotine exposure, sleep, body mass index, lipids, blood glucose, and blood pressure. We related total LE8 score, score components, and change in LE8 score over 8 years with peak V̇O 2 (log‐transformed) and complementary CRF measures. In age‐ and sex‐adjusted linear models (N=1838, age 54±9 years, 54% women, LE8 score 76±12), a higher LE8 score was associated favorably with peak V̇O 2 , ventilatory efficiency, resting heart rate, and blood pressure response to exercise (all P <0.0001). A clinically meaningful 5‐point higher LE8 score was associated with a 6.0% greater peak V̇O 2 (≈1.4 mL/kg per minute at sample mean). All LE8 components were significantly associated with peak V̇O 2 in models adjusted for age and sex, but blood lipids, diet, and sleep health were no longer statistically significant after adjustment for all LE8 components. Over an ≈8‐year interval, a 5‐unit increase in LE8 score was associated with a 3.7% higher peak V̇O 2 ( P <0.0001). Conclusions Higher LE8 score and improvement in LE8 over time was associated with greater CRF, highlighting the importance of the LE8 factors in maintaining CRF.