Objective: To determine if a heart rate-based protocol for bronchial provocation testing ensures sufficient exercise intensity for inducing exercise-induced bronchial obstruction.
Participants: 100 clinically healthy non-asthmatic sports students.
Design: Subjects underwent an exercise challenge test (ECT) on a treadmill ergometer for bronchial provocation according to the guidelines of the American Thoracic Society (ATS). Heart rate (HR), forced expiratory volume in 1 second (FEV1), pH (pH) and lactate concentration were measured before and after exercise.
Results: After exercise in 56% of the examined subjects lactate concentrations were <6 mmol/l. A highly significant decrease in FEV1 (mean −4.41 (SD 1.5%)) was found at concentrations of >6 mmol/l, whereas at concentrations <6.48 mmol/l, no participant showed an impairment of lung function (FEV1 values ⩽90%). In five subjects, a bronchial obstruction was found, as shown by decreases in FEV1 of −10 to −47% after exercise. The lactate concentrations in these individuals were between 6.48 and 11.7 mmol/l, indicating a predominantly anaerobic metabolic response to exercise.
Conclusion: These results show that the ATS standard protocol, using a heart rate formula for assessing the exercise intensity, is not sufficient to cause predominantly anaerobic lactate metabolism and hence exercise-induced hyperventilation. Therefore, a potential bronchial obstruction could not be induced in 56% of the subjects. For a sensitive study design, exercise intensities demanding anaerobic lactate metabolism should always be ensured. A more precise protocol is required.
Statistics from Altmetric.com
Competing interests: None declared.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.