Refining Maximal Heart Rate Estimation to Enhance Exercise Recommendations for Persons With Parkinson Disease

Abstract

Objective: To derive and evaluate an alternative equation to estimate maximal heart rate in persons with Parkinson disease (PD) in the absence of structured exercise testing using observed maximal heart rate data from a maximal cardiopulmonary exercise test (CPET) and basic demographic and clinical data.

Design: Baseline data from a randomized controlled trial.

Setting: Academic Medical Center.

Participants: Eighty-two persons with mild-to-moderate PD who completed a CPET.

Interventions: Not applicable.

Main outcome measures: A linear regression model was fit to maximal heart rate from CPET using the relaxed least absolute shrinkage and selection operator (lasso) and 7 readily clinically accessible candidate covariables. Model fit was assessed by leave-one-out cross-validation. Maximal heart rates from the CPET were compared with estimates from the regression model and from 2 traditional age-based maximal heart rate estimators: (220 - age) and [208 - (0.7 × age)].

Results: The regression-based heart rate estimator was [166 - (1.15 × age) + (0.60 × resting heart rate)] and most closely fit the observed maximal heart rate from the CPET. The (220 - age) and [208 - (0.7 × age)] equations overestimated maximal heart rate for 88% and 94% of the participants, respectively. The mean square error of the regression-based estimator was 63% and 75% lower than those of the 2 traditional age-based estimators, respectively.

Conclusions: Overestimating maximal heart rate generates prescribed target heart rate zones that are likely unachievable during aerobic exercise. The proposed regression-based maximal heart rate estimator most closely fit observed maximal heart rates from the CPET. Adoption of this estimator, based on both age and resting heart rate, may improve estimated maximal heart rate accuracy and thus provide more appropriate and achievable exercise heart rate zones for persons with PD in the absence of a CPET.

Keywords: Aerobic exercise; Autonomic dysfunction; Chronotropic incompetence; Parkinson disease; Rehabilitation.