High Cardiorespiratory Fitness Levels Slow the Decline in Peak Heart Rate with Age

INTRODUCTION: Although it is well accepted that peak HR (HRpeak) decreases with age, there is no clear consensus on the rate of this decline and the influence of cardiorespiratory fitness (CRF) on the rate of decline. METHODS: Treadmill cardiopulmonary exercise test (CPET) results with RER ≥ 1.0 from participants (1849 men and 1469 women; 18-80 yr) of a university-based health assessment/fitness program were retrospectively examined using cross-sectional and longitudinal study designs. All subjects were free of overt cardiovascular disease and were not taking HR-altering medications. Only subjects having completed ≥ 2 cardiopulmonary exercise tests with ≥ 1 yr between test dates were included in the longitudinal analysis (418 men and 225 women). Subjects were categorized into CRF categories (high, moderate, and low) relative to age and gender normative classifications. A general linear-model univariate analysis was performed to test the effect of CRF on the decline in HRpeak with age. RESULTS: In both cross-sectional and longitudinal analyses, HRpeak declined at a significantly faster rate across the CRF categories (cross-sectional: -0.60, -0.78, and -0.87 bpm · yr(-1), respectively; longitudinal: -0.61, -0.82, and -1.02 bpm · yr(-1), respectively). CONCLUSIONS: This study provides evidence that the maintenance of a high or moderate CRF may slow the age-related decline in HRpeak in both men and women. The application of CRF-specific HRpeak prediction equations should be used to improve interpretation of HRpeak from exercise tests.