Longitudinal Examination of Age-Predicted Symptom-Limited Exercise Maximum Heart Rate

Na Zhu,^*,1 Jose Suarez,^*,1 Steve Sidney,² Barbara Sternfeld,² Pamela J. Schreiner,¹ Mercedes R. Carnethon,³ Cora E. Lewis,⁴ Richard S. Crow,¹ Claude Bouchard,⁶ William Haskell,⁵ and David R. Jacobs, Jr^1,7

Abstract

Purpose

To estimate the association of age with maximal heart rate (MHR).

Methods

Data were obtained in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were black and white men and women aged 18-30 in 1985-86 (year 0). A symptom-limited maximal graded exercise test was completed at years 0, 7, and 20 by 4969, 2583, and 2870 participants, respectively. After exclusion 9622 eligible tests remained.

Results

In all 9622 tests, estimated MHR (eMHR, beats/minute) had a quadratic relation to age in the age range 18 to 50 years, eMHR=179+0.29*age-0.011*age². The age-MHR association was approximately linear in the restricted age ranges of consecutive tests. In 2215 people who completed both year 0 and 7 tests (age range 18 to 37), eMHR=189–0.35*age; and in 1574 people who completed both year 7 and 20 tests (age range 25 to 50), eMHR=199–0.63*age. In the lowest baseline BMI quartile, the rate of decline was 0.20 beats/minute/year between years 0-7 and 0.51 beats/minute/year between years 7-20; while in the highest baseline BMI quartile there was a linear rate of decline of approximately 0.7 beats/minute/year over the full age of 18 to 50 years.

Conclusion

Clinicians making exercise prescriptions should be aware that the loss of symptom-limited MHR is much slower at young adulthood and more pronounced in later adulthood. In particular, MHR loss is very slow in those with lowest BMI below age 40.

Keywords: prediction equations, graded exercise test, mixed models, epidemiologic study

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2891874/