a previous double-blind, placebo-controlled study involving
administration of once-daily LAMA, tiotropium, in which
a statistically significant difference in endurance time was
reported between tiotropium and placebo after 21 days (13.6%,
P = 0.039) and after 42 days of treatment (21.4%,
P = 0.0098).14
The magnitude of the effect increased during the 3-week
treatment period, which may have been due to further adaptive
responses following improved ventilatory mechanics.
It is thus possible that treatment periods longer than 3 weeks
may yield larger treatment improvements in exercise
endurance.13,14 Additionally, reduced airway obstruction may,
over time, result in increased activity with a training effect
and lead to further improvements in exercise tolerance. Such
improvements in exercise capacity have been noted in studies
examining pulmonary rehabilitation.25
Improvement in exercise capacity is recognized as an
important goal in the management of COPD.5 Dyspnea is