ABSTRACT
The purposes of this study were to determine the effect of interval workload exercise protocol on selected pulmonary functions in asthmatic subjects with exercise-induced bronchospasm [EIB], and to demonstrate the difference between using interval exercise protocol alone and the combination of it with administration of short-acting bronchodilator beta2-agonists on pulmonary functions for the same subjects. Twenty-six asthmatic subjects, fifteen males and eleven females aged 35.61 +/- 2.5 years with a history of EIB participated in the study. They were in stable clinical and physiological conditions. Subjects did not administer any medicines 24 hours prior to each intervention. All subjects were enrolled in two interventions study procedures. In the first intervention, they practice interval workload exercise protocol of 60% - 40% of their maximum work rate [MWR], which is determined previously by using symptom-limited exercise test, for 30 minutes by bicycle ergometer. While in the second intervention, short-acting bronchodilator beta2-agonists was administered through pressurized metered-dose inhaler and after 10-minutes, they practice the same exercise protocol as in the first intervention. Selected pulmonary function measures of EVC, FEVI, FEVI% pred., MVV and RR were recorded pre, during and immediately after cessation of exercise and after 15 minutes rest by using computerized spirometry. On comparing during exercise parameters between the first and second interventions, it was found a significant [P<0.05] decrease in RR [26.2 +/- 3.2 vs. 20.9 +/- 2.1 C/M] in the second intervention. While on comparing the two interventions immediately after cessation of exercise, it was found a significant [P<0.05] increase in FEVI% pred. [69.4 +/- 7.5 vs. 80.5 +/- 6.8%], in PEFR [5.5 +/- 1.4 vs. 6.9 +/- 1.5 L/S] and in MVV [95.1 +/- 20.0 vs. 98.4 +/- 19.0 L/M], while RR showed significant [P<0.05] decrease [28.7 +/- 3.2 vs. 21.8 +/- 1.8 C/M] in the second intervention. On comparing the pulmonary function parameters for both interventions after 15 minutes rest, it was found a significant increase [P<0.05] in FVC [2.5 +/- 0.6 vs. 3.0 +/- 0.4 L], in FEVI [2.4 +/- 0.6 vs. 2.9 +/- 0.5 L], in FEVI% pred. [68.6 +/- 5.7 vs. 76.8 +/- 3.3%] and in MVV [95.8 +/- 14.2 vs. 102.6 +/- 20.1 L/M]. Interval workload exercise protocol is efficient in asthmatic subjects with a history of EIB and it can be used in pulmonary rehabilitation and during carrying out their daily activities. Short-acting bronchodilator 2-agonists that are used in occasions before exertion can be replaced by practicing the exercise or the daily activities as an interval exercise workload protocol, to improve the cardiopulmonary fitness and to avoid the adverse reactions of 2-agonists