RT Journal Article
SR Electronic
T1 Heart rate-based protocols for exercise challenge testing do not ensure sufficient exercise intensity for inducing exercise-induced bronchial obstruction
JF British Journal of Sports Medicine
JO Br J Sports Med
FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine
SP 429
OP 431
DO 10.1136/bjsm.2007.041715
VO 43
IS 6
A1 C Trümper
A1 S Mäueler
A1 C Vobejda
A1 E Zimmermann
YR 2009
UL http://bjsm.bmj.com/content/43/6/429.abstract
AB 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.