Vagal activity and airway response to ipratropium bromide before and after exercise in ambient and cold conditions in healthy cross-country runners.
OBJECTIVE
To determine whether the variability in the effect of ipratropium bromide on the bronchial response to exercise among endurance athletes depends on their vagal activity. The hypothesis was that this would be the case.


METHODS
Participants served as their own controls in a double-blind, repeated-measures investigation.


METHODS
Climatic chamber in an exercise laboratory.


METHODS
Six well-trained healthy adult cross-country runners (three women and three men).


METHODS
Four exercise provocation tests at ambient temperature of 22 or -5 degrees C after inhalation of ipratropium bromide or placebo.


METHODS
Vagal activity was assessed in each visit by a 4-second cycling test; airway response to exercise was measured by periodic pulmonary function testing.


RESULTS
With ipratropium bromide, forced expiratory volume in 1 second (FEV1) increased by 5.3+/-1.4% at 22 degrees C and by 7.5+/-1.5% at -5 degrees C. The beneficial response of the large airways to ipratropium bromide versus placebo was positively related to vagal activity for FEV1 at -5 degrees C, for peak expiratory flow (PEF) at -5 degrees C, and for PEF at 22 degrees C.


CONCLUSIONS
The findings suggest that the beneficial large-airways response to ipratropium bromide may be related to vagal activity.


CONCLUSIONS
Information about vagal activity may help to determine whether an athlete is a suitable candidate for treatment with ipratropium bromide. This may offer more therapeutic possibilities, especially for those individuals who have a high vagal activity, such as endurance athletes.
Knöpfli
B H
BH
Children's Exercise and Nutrition Centre, McMaster University, Hamilton, Ontario, Canada.
Bar-Or
O
O
D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000502:physiology; D001985:Bronchial Provocation Tests; D003080:Cold Temperature; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005080:Exercise Test; D005260:Female; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage*; D008297:Male; D010101:Oxygen Consumption; D010276:Parasympatholytics / Q000008:administration & dosage*; D010807:Physical Endurance / Q000187:drug effects*; D012016:Reference Values; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology; D012420:Running / Q000502:physiology*; D013696:Temperature; D014630:Vagus Nerve
D010276:Parasympatholytics; D009241:Ipratropium