This study compared the two step heights (35 cm vs. height adjusted according to the 90° knee angle) on the predictions of the VO2max predicted with their step indexes (SI) and steady heart rates (HR) during the test. Twenty-one college male students were the subjects (age: 21.71+0.45 years old, height: 174.7±7.1cm, weight: 69.9±8.1kg, VO2max: 45.41±1.30 ml/kg/min). VO2max was measured by the cycle ergometer with increasing workload. Participants performed respectively twice the step test which were divided into Fixed Height (FH: 35 cm) and Modified Height (MH: modification of the step height based on 90° knee angle). The frequency of the step test is 24 step/min for 3 minutes. The heart rate during exercise was measured to estimate HR, and the heart rate after exercise was measured to estimate SI. The results were as follows: First, correlation analyses between VO2max and the VO2max predicted by SI-FH and SI-MH were in significant (r=.469, p<.05; r=.681, p<.05). Second, correlation analyses between VO2max and the VO2max predicted by HR-FH 及HRMH were significant (r=-.626, p<.05; r=-.582, p<.05). Third, there was no difference between measured VO2max and predicted VO2max by SI-FH, SI-MH, HR-FH and HR-MH (p>.05). The correlation between VO2max and the VO2max predicted by SI of MH was higher than that of FH. The correlation between VO2max and the VO2max predicted by HR of FH was higher than that of MH. The step height adjusted according to the 90° knee angle can improve the validity to predict VO2max.
This study compared the two step heights (35 cm vs. height adjusted according to the 90° knee angle) on the predictions of the VO2max predicted with their step indexes (SI) and steady heart rates (HR) during the test. Twenty-one college male students were the subjects (age: 21.71+0.45 years old, height: 174.7±7.1cm, weight: 69.9±8.1kg, VO2max: 45.41±1.30 ml/kg/min). VO2max was measured by the cycle ergometer with increasing workload. Participants performed respectively twice the step test which were divided into Fixed Height (FH: 35 cm) and Modified Height (MH: modification of the step height based on 90° knee angle). The frequency of the step test is 24 step/min for 3 minutes. The heart rate during exercise was measured to estimate HR, and the heart rate after exercise was measured to estimate SI. The results were as follows: First, correlation analyses between VO2max and the VO2max predicted by SI-FH and SI-MH were in significant (r=.469, p<.05; r=.681, p<.05). Second, correlation analyses between VO2max and the VO2max predicted by HR-FH 及HRMH were significant (r=-.626, p<.05; r=-.582, p<.05). Third, there was no difference between measured VO2max and predicted VO2max by SI-FH, SI-MH, HR-FH and HR-MH (p>.05). The correlation between VO2max and the VO2max predicted by SI of MH was higher than that of FH. The correlation between VO2max and the VO2max predicted by HR of FH was higher than that of MH. The step height adjusted according to the 90° knee angle can improve the validity to predict VO2max.