Can the 6MST be used to estimate endurance training intensity? A cross sectional study.

<bold>Background:</bold> Home-based pulmonary rehabilitation (PR) can address the limited access to center-based programs. This approach notwithstanding requires an in-center evaluation as no home-feasible field test has been validated to estimate endurance training intensity. <bold>Aim:</bold> To evaluate the predictive capability of the six-minute stepper test (6MST) in determining training intensity based on cardiopulmonary exercise testing (CPET). <bold>Method:</bold> A multicenter (N=3) cross-sectional study including COPD patients referred for PR with CPET was conducted. Participants underwent two 6MSTs and its predictive capability in determining heart rate at the ventilatory threshold (HRvt), corresponding workload (Wvt), and peak workload (Wpeak) based on CPET was assessed using multivariate stepwise regression, incorporating physiological parameters and performance during the 6MST as well as baseline characteristics. <bold>Results:</bold> One-hundred and five patients were included. They were aged 61 (SD 9) years, weighted 70 (SD 14) kg, had moderate obstruction (FEV1: 61 (SD 21) %), impaired exercise capacity (VO2peak 15.5 (SD 4.4) ml/kg/min) and they performed 231 (SD 74) steps during the 6MST. Predictive equations and correlation coefficients are shown in table 1. <bold>Conclusion:</bold> The 6MST may be useful in estimating endurance training intensity. Future study should assess the external validity these findings. <table-wrap><object-id>erj;64/suppl_68/PA600/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col></colgroup><tbody><tr><td>Predictive equations</td><td>R², p value</td></tr><tr><td>HRvt = 0.60 x HR1-3 (bpm) + 0.661 x BMI (kg/m²) – 0.33 x age (years) + 49.54</td><td>0.377, p<0.01</td></tr><tr><td>Wvt = 0.44 x weight (kg) + 0.15 x step count + 8.37 x FEV1 (L) -0.08 x HR4-6 (bpm) -24.29</td><td>0.615, p<0.01</td></tr><tr><td>Wpeak = 0.61 x weight (kg) + 0.22 x steps count + 18.74 x FEV1 (L) -0.15 x HR4-6 (bpm) -29.83</td><td>0.745, p<0.01</td></tr></tbody></table></table-wrap>