Performance, metabolic, hemodynamic, and perceived exertion in the six-minute step test at different heights in a healthy population of different age groups

Introduction: The 6-minute step test (6-MST) uses the movement of moving up and down a platform, a common activity in daily life. Because it combines low cost and requires little physical space, this test is an alternative to other functional tests. However, it lacks further standardization, as there are several protocols in the literature using different step heights. Objectives: compare the performance, metabolic, hemodynamic, and perceived exertion during the 6-MST conducted with different step heights. Besides, compare the performance between different age groups for each step height. The association between age, body mass index, level of physical activity, lower limb measurements with performance was also evaluated. Methods: This is a cross-sectional study. The IPAQ short form was used to evaluate the level of physical activity. Performance, metabolic, hemodynamic, and perceived exertion were assessed at rest, during, and immediately after the 6-MST. Healthy participants, aged between 18 and 79 years, underwent three-step tests (15-, 20-, and 30-cm) on the same day, in randomized order. Results: Forty-four participant's performance in the test with the highest step was significantly lower compared to those with the lowest height (149 ± 27 vs. 170 ± 29 and 180 ± 35; p<0,05). The estimated peak oxygen consumption (VO2peak) increased ~2.5 ml.kg-1·min-1 with the increase of step height. Both the delta-heart rate (delta-HR) and dyspnea measured with the Modified Borg Scale (MBS) were higher in the 30 cm step height test (delta-HR= 55.5 ± 18.9; MBS= 5.0 (0-9.0)) compared with the 15 cm (delta-HR= 36.7 ± 15.1; MBS= 3.0 (0-9.0)) and 20 cm step height test (delta-HR= 43.5 ± 15.4; MBS= 3.0 (0-8.0). There was a moderate correlation between performance with BMI (r= -0.31 to -0.39) and physical activity level (r= 0.29 to 0.46) regardless of the step height. Conclusion: The higher step height caused greater cardiovascular stress, without exceeding the submaximal levels of the test, indicating that the 6-MST can be used as an alternative instrument for evaluating aerobic capacity in healthy individuals. Keywords: exercise test; 6-minute step test; health