Loss of skeletal muscle has long been established as a feature of stable COPD. COPD patients have decreased quadriceps strength and fat-free mass [53]. These effects are worse after acute exacerbations. These effects may be more pronounced if we take into consideration that these patients received high doses of corticosteroids during an exacerbation. Further data related to the impact of exacerbation on exercise activity is the work by DONALDSON et al. [34]. In a longitudinal study, these investigators quantified time spent outdoors, and found that frequent exacerbators had spent less time. These investigators identified decreased activity a few days prior to exacerbations, which remained decreased for up to 5 weeks. More recent studies have utilised ambulatory activity monitoring. PITTA et al. [54] confirmed prior reports, and also described decreased activity level in patients that have exacerbations compared with those who did not. Furthermore, a decreased activity level 1 month after an exacerbation was associated with increased risk for hospitalisation. Thus, the investigators concluded that exacerbations decreased the overall exercise tolerance.