BackgroundAerobic exercise appears to have clinical benefits for many asthmatics, yet a complete understanding of the mechanisms underlying these benefits has not been elucidated at this time.PurposeThe objective of this study was to determine feasibility for a larger, future study that will define the effect of aerobic exercise on cellular, molecular, and functional measures in adults with mild-moderate asthma.DesignRecruited subjects were randomized into usual care (sedentary) or usual care with moderate intensity aerobic exercise treatment groups.Setting / ParticipantsNineteen adults with mild-moderate asthma but without a recent history of exercise were recruited at the UAB Lung Health Center, Birmingham, AL.InterventionThe exercise group underwent a 12 week walking program exercising at 60 – 75% of maximum heart rate (HRmax). Subjects self-monitored HRmax levels using heart rate monitors; exercise diaries and recreation center sign-in logs were also used.Main outcome measuresFunctional measures, including lung function and asthma control scores, were evaluated for all subjects at pre- and post-study time-points; fitness measures were also assessed for subjects in the exercise group. Peripheral blood and nasal lavage fluid were collected from all subjects at pre- and post-study visits in order to evaluate cellular and molecular measures, including cell differentials and eosinophilic cationic protein (ECP).ResultsSixteen subjects completed the prescribed protocol. Results show that subjects randomized to the exercise group adhered well (80%) to the exercise prescription and exhibited a trend toward improved fitness levels upon study completion. Both groups exhibited improvements in ACQ scores. No changes were observed in lung function (FEV1, FEV1/FVC), cell differentials, or ECP between groups.ConclusionsResults indicate that a moderate intensity aerobic exercise training program may improve asthma control and fitness levels without causing asthma deterioration in adult asthmatics. As such, these findings demonstrate the feasibility of the study protocol in preparation for a larger, clinical trial that will elucidate the functional consequences of aerobic exercise on asthmatic cellular and molecular responses.

RATIONALE: Increasing evidence indicates that decreased physical activity may play a role in asthma development (Lucas & Platts-Mills, 2005). In light of this evidence, this study has examined the effect of moderate intensity aerobic exercise on asthmatic responses in adult patients. METHODS: We have completed a randomized, parallel group proof of concept study in which sixteen adults (33 -78yrs) with mild to moderate persistent asthma were assigned randomly to either: i) a 12-week protocol of moderate intensity aerobic exercise plus usual care or ii) a 12-week protocol of usual care only. All participants had evidence of reversibility via spirometry as performed by the ATS guidelines. Exercise participants completed a walking program at a frequency of 3x/wk, 60 -75% of agepredicted HRmax. RESULTS: Before and after protocol completion, participants were monitored for differences in asthma control, lung function, and proinflammatory targets in peripheral blood and nasal lavage. Results suggest that participants in the exercise group exhibited a trend toward improved fitness levels, including increased VO2 peak and total treadmill time. Subjects in both groups exhibited improved asthma control; no changes were observed in lung function or pro-inflammatory mediator levels. As indicated by heart rate monitors and exercise logs, adherence in the exercise group was 86%. CONCLUSIONS: This study has demonstrated the feasibility of the protocol and measurements, established proof of concept, and generated preliminary data for a larger, clinical efficacy trial that will test the efficacy of exercise as an adjunct therapy for the treatment of asthma.

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