Reductions in daily physical activity levels are related to clinically relevant outcomes in patients with COPD, such as concurrent cardiometabolic morbidities,5,6 reduced health status,7 and hospital admissions and readmissions.8,9 Moreover, patients with COPD who had low to very low levels of daily physical activity had higher mortality rates compared with patients with COPD who were physically active to some extent.9 In this issue of CHEST (see page 331), Waschki and colleagues10 also report an association between baseline levels of physical activity and the probability of 4-year survival in 169 patients with mild to very severe COPD. Physically inactive patients with COPD have the worst prognoses. Even though the studied sample is relatively small for a survival study, this study adds significantly to the existing literature. First, Waschki et al10 used accelerometer-derived data to assess daily physical activity levels in patients with COPD, while others used data from a physical activity questionnaire,9 which is known to lack precision. Second, Waschki et al10 included multiple pulmonary and nonpulmonary outcomes that had been related individually (eg, degree of dyspnea, static hyperinflation, cardiac function, systemic biomarkers of inflammation, mood status, health status, body composition, and 6-min walk distance test) or in combination (eg, the BODE [BMI, airflow obstruction, dyspnea, and exercise capacity] index and the ADO [age, dypsnea, and airflow obstruction] index) with survival in patients with COPD. Still, baseline levels of daily physical activity were the strongest predictors of 4-year all-cause mortality. Even though the exact mechanisms underlying this relationship remain poorly understood, the findings of Waschki et al10 do result in the interesting hypothesis that increasing physical activity levels may reduce mortality risk in patients with COPD. Whether and to what extent reversibility of physical inactivity will result in a better survival rate remains unknown and warrants further investigation.