Post-Exercise Palpation of Pulse Rates

Abstract

0066 Despite the intense marketing of heart rate (HR) monitors, endurance-trained adults as well as participants involved in group exercise settings (e.g., aerobic dancing) still rely on the palpation of pulse rates to periodically monitor exercise intensity. However, due to the rapid recovery of HR following exercise, post-exercise palpation of pulse rates may underestimate exercise HR in this population. Futhermore, because baroreceptor sensitivity is increased in endurance-trained individuals, carotid palpation may cause reflex reductions in heart rate. PURPOSE: To determine the accuracy of carotid and radial palpation in estimating exercise heart rate and the effect of carotid palpation on HR following exercise in an endurance-trained population. METHODS: Twenty young healthy endurance-trained adults (24±1 yr) performed two sets of submaximal exercises for five min at 70 and 85% of maximal HR on the treadmill; one with carotid pulse count and another with radial pulse count, in a randomized order. RESULTS: Post-exercise palpation of pulse rate was substantially lower (P<0.01) than the actual HR during exercise. On average, HR was underestimated by 20 and 27 beats per min at lower and higher intensities of exercise. Even when ECG-derived HR was analyzed immediately after exercise, a significant underestimation of exercise HR (seven to nine beats per min lower) still persisted (P<0.05). Pulse rate obtained by carotid palpation following exercise at both intensities and radial palpation at the lower intensity was no different from HR measured with ECG after exercise. In the radial artery trial at the higher exercise intensity, pulse rate following exercise was lower (P<0.05) than ECG-derived HR. Carotid palpation did not significantly affect HR following exercise at either exercise intensity. Augmentation index and pulse wave velocity, which are measures of arterial stiffness that are closely associated with arterial baroreflex sensitivity, were not significantly related to the changes in HR with carotid palpation. CONCLUSION: Post-exercise pulse counts may not be appropriate as an indicator of exercise intensity in endurance-trained adults. Supported by NIH Grant AG20966