Heart rate as an estimator of oxygen consumption during manual postal delivery.
研究通过模拟邮递任务，发现心率估算耗氧量仅在测试工作与职业肌肉工作相似时才准确，为职业体力负荷评估提供参考。
Nine young healthy postmen performed three progressive maximal exercise tests (on a bicycle ergometer and with and without a 10-kg shoulder bag on a treadmill) for which the least-squares regression equations of heart rate (HR) on oxygen consumption (VO2) were established. HR and VO2 were then measured during five modes of simulated postal delivery: on level ground by foot (F), bicycle (B), and push-cart (C) and on stairs by foot (S/F) and push-cart (S/C). The respective work HR values were inserted into the three regression equations established for HR/VO2, and VO2 was solved for. The estimated VO2 values tended to be systematically higher than the measured ones. The best regression proved to be that established for the treadmill plus mailbag; the regression coefficients between the measured and estimated VO2s were higher than 0.75, and the percentage differences between the means of the measured and estimated values were no more than 10% for F and B delivery. All the regressions yielded inaccurate estimations of VO2 for C, S/F and S/C delivery. It was concluded that HR is acceptable as an estimator of VO2 only when the test work closely resembles the muscle work in the job.