LAUSR

Introduction: Physical activity in daily life (PADL) has been widely studied in subjects with chronic obstructive pulmonary disease (COPD). However, relationship of PADL with variables from maximal exercise tests still lacks attention in the literature. Aim: To identify whether maximal exercise capacity presents discriminative capacity to identify physical activity/inactivity in subjects with COPD. Methods: Fourteen subjects with COPD (9 men) were assessed regarding lung function, PADL (SenseWear® ArmBand during seven days) and maximal exercise capacity (incremental shuttle waking test, ISWT). Furthermore, subjects wore the PADL monitor during the ISWT in order to determine maximal METs achieved. Results: The 3-METs threshold represented 57(35–73)% of the maximum (%max). The intensity of 48%max was identified as point of better discriminative capacity to identify inactive subjects (area under the curve [AUC] 0.64[95%CI 0.27–0.99]; sensitivity 1; specificity 0.36). However lower values were found for the discrimination of active subjects (AUC 0,36[95%CI 0.001–0.73]). Additionally, for 3-METs, 79% of subjects were classified as active and 21% as inactive, whereas for the %max, 86% of subjects were classified as active and 14% inactive (P>0.05). Among subjects in which 3 METs represented lower than 48%max, there was no subject classified as inactive. However, among subjects in which 3METs represented higher than 48%max, 30% of subjects were classified as inactive and 70% as active (P>0.05). Conclusion: These preliminary results show that maximal exercise intensity had good discriminative capacity to identify physical inactivity in subjects with COPD.