Abstract

OBJECTIVE--To establish the accuracy of the traditional method of measuring the intensity of exercise in aerobic dance classes, that is, intermittent pulse palpation performed during a brief cessation of activity. METHODS--A short wave telemetry system was used to record heart rates during a class in a group of 12 healthy women aged 26 (SD 6) years. Subjects palpated their pulses for 10 s following high and low intensity exercise [78(8)% and 69(9)% of mean predicted maximum heart rate respectively]. Recorded exercising heart rates, averaged over 60 s preceding pulse palpation [ExHR(rec)], were compared with the recorded postexercise heart rates averaged over the 10 s palpation period [PostExHR(rec)] and with the palpated counts (PalpHR). Differences were assessed using Student's t test and Wilcoxon signed rank test. RESULTS--Differences between ExHR(rec) and PostExHR(rec) following high and low intensity exercise [3(6) beats.min-1 and 5(7) beats.min-1 respectively] were not significant. However, the wide variation between subjects means that a postexercise heart rate is unreliable as a measure of individual exercise intensity. PalpHR was significantly lower than ExHR(rec) (P < 0.01). Every individually palpated count underestimated the exercising heart rate (range 9 to 95 beats.min-1). CONCLUSIONS--While postexercise heart rate adequately represents the exercise heart rate for a group, the individual variation is too wide for this to be a useful measurement.