Assessing exercise intensity in cardiac rehabilitation: the use of a Polar heart rate monitor

Objective: To assess the accuracy of a Polar heart rate monitor in measuring heart rate in exercising cardiac rehabilitation patients. Design: Simultaneous heart rate recordings comparing results from the Polar monitor with those from Holter monitoring and intermittent pulse rate as measured by radial artery palpation. Setting: Exercise sessions in a community-based cardiac rehabilitation centre. Patients: Twenty phase III cardiac rehabilitation patients recovering from an acute cardiac event. Main outcome measures: Comparison of heart rates recorded by the two systems and by pulse rate measurement. Results: The Polar monitor gave results very similar to those from Holter monitoring. Intermittent pulse rate measurement gave a limited and less accurate view of the intensity of the exercise session. Conclusion: The Polar heart rate monitor gives accurate readings during cardiac rehabilitation exercise sessions at low cost. It is a useful tool which allows assessment of exercise intensity which is not available from intermittent radial pulse rate measurement.