Exercise Training Programs Improve Cardiorespiratory and Functional Fitness in Adults With Asthma A SYSTEMATIC REVIEW AND META-ANALYSIS

Purpose: This systematic review aimed to identify the characteristics and determine the effects of exercise interventions on improving health-related physical fitness in adults with asthma. Review Methods: A systematic search was completed in MEDLINE, CINAHL, Embase, and SPORTDiscus for peer-reviewed publications of experimental studies that investigated the effects of an exercise training intervention on performance-based health-related physical fitness outcomes in adults with asthma. Two reviewers independently screened studies for inclusion according to predetermined criteria and performed data extraction and quality assessment of included studies. Forty-five articles were included, in which results for 39 unique studies were reported. Subjects (n = 2135) were aged 22 +/- 4 to 71 +/- 11 yr with mild-severe asthma. Most exercise programs used aerobic exercise, either alone or in combination with resistance or breathing/stretching exercises. The most common exercise program characteristics were supervised moderate-to-vigorous intensity aerobic exercise performed for 30-45 min 3 d/wk. Meta-analyses revealed significant improvements in cardiorespiratory fitness (Vo2peak: unstandardized mean difference [MD] 3.1 mL/kg/min, 95% CI, 1.9-4.3), functional fitness (walking distance: MD 41 m, 95% CI, 27-54), and overall health-related physical fitness (standardized mean difference [SMD] 0.67, 95% CI, 0.46-0.89) in favor of groups who underwent experimental exercise training interventions. Aerobic exercise elicited superior improvements in health-related physical fitness compared with breathing/stretching exercise (SMD 0.47, 95% CI, 0.14-0.81). Supervised exercise training programs, particularly those aerobic in nature, are effective in eliciting clinically meaningful improvements in cardiorespiratory and functional fitness in adults with asthma. PROSPERO registration ID number = CRD42018092828.