A shorter mucociliary clearance time was also found in
nonsmokers who performed aerobic exercise. This finding
is in agreement with data described in a previous study,7
which reported acceleration of mucociliary clearance after
aerobic exercise in healthy subjects as demonstrated by
analysis of radiolabeled particles. However, Olseni et al43´
found that moderate exercise did not improve mucociliary
clearance in subjects with bronchial hypersecretion. This
suggests that the mucociliary clearance response to exer-
cise is influenced by the properties and amount of mucus.
The acute responses of this mechanism following moder-
ate exercise in both smokers and nonsmokers in our study
may be related to the fact that no subject had hypersecre-
tion in the upper airways, as confirmed by the question-
naire addressing any respiratory infections that preceded
each experimental protocol.