1998 Volume 33 Issue 3 Pages 147-153
The purpose of this study is to establish a new method for the evaluation of workload in terms of heart rate (HR). A box step stress test would be a better alternative to the bicycle-ergonometer test because of its simple components and portability.
We performed three kinds of tests in order to find the appropriate height and rate of stepping for the step stress test. We recorded the HR with varying the step rate at a constant step height, varying the height at a constant rate, and varying the step height and rate under constant power (the product of step height and rate is constant). The results were as follows:
1) There was a strong correlation between HR and the physical power of the step stress test. Also, there was a strong correlation between the consumption volume of oxygen (V02) and physical power. The coefficient of correlation, in both cases, was larger than 0.99 in all subjects.
2) Sixteen subjects out of 18 tested, showed the minimum HR and V02 when the step height was 30cm and the step rate was 20 steps/min. These results show that 30cm and 20 steps/min is the most suitable height and speed for average-sized individuals.
3) The HR for the step stress test at 30cm×20 steps/min was 120 to 150 beats/min. Since the HR was greater than 110 beats/min, we believe that the HR was not affected by mental stress.
4) The above results show that the step stress test can be used for the bicycle-ergonometer test to determine power. The test with 30cm height at 20 steps/min was found as the most appropriate step stress test for subjects 150-180cm tall.
