Abstract 18860: Cardiorespiratory Fitness Affects the Rate of Decline of Maximal Heart Rate with Age
Introduction: There is a general consensus that an individual’s cardiorespiratory fitness (CRF) does not affect the rate of decline of maximal heart rate (HRmax) with age. This consensus was developed primarily from large cross-sectional studies performing symptom limited exercise tests, which lack cardiometabolic data to confirm the achievement of true maximal effort and are limited to predicting CRF.
Methods: Maximal cardiopulmonary exercise test (CPET) results, with directly measured CRF, from participants (1161 men, 1070 women) of a university based health-assessment/fitness program were examined. Participants’ data were included if they performed a CPET on a treadmill, achieved a respiratory exchange ratio ≥1.0 and were not taking HR altering medications. Only subjects having completed ≥2 CPETs with ≥1 year between test dates were included in the longitudinal analysis (282 men, 172 women). Subjects were categorized into CRF categories (high, moderate, and low) relative to age and gender normative classifications. To determine the effect of CRF an interaction between fitness and age was tested, with HRmax as the dependent variable.
Results: The rate of decline of HRmax for the whole cohort in the cross-sectional and longitudinal analyses were -0.79 and -0.81 beats per minute (bpm) per year, respectively. Higher fit individuals had a significantly slower rate of decline of HRmax compared to individuals with a lower CRF. In the cross-sectional analysis the HRmax decline with age in the high, moderate, and low fit subjects were -0.61, -0.79, and -0.90 bpm per year, respectively, and -0.65, -0.83, -1.07 bpm per year, respectively in the longitudinal analysis.
Conclusions: In conclusion, this study provides evidence that high CRF delays and low CRF accelerates the rate of decline in HRmax with age. The application of CRF specific, HRmax prediction equations, can improve the interpretation of HRmax in exercise testing laboratories.
Author Disclosures: C. Ozemek: None. M.H. Whaley: None. H.W. Finch: None. L.A. Kaminsky: None.
- © 2014 by American Heart Association, Inc.