Although regular exercise improves asthma control in adults as measured by the Asthma Control Test (ACT), it has little effect on peak expiratory flow (PEF) variability, according to a study published in Scientific Reports.
The Regular Exercise and Asthma Control Trial was a randomized, controlled trial designed to test the hypothesis that asthma control in adults would be improved by a 24-week exercise intervention. Adult participants with mild to moderate asthma were randomly assigned to a reference group (RG, n=82) or an exercise intervention group (iG, n=82). Participants in the iG group followed an individualized exercise program that included at least 30 minutes of aerobic exercise at least 3 times per week, along with stretching and strength training. Of the 105 participants who completed the trial, 89 (68%) provided sufficient information for analyses (n=44 iG and n=45 RG). The primary end point was asthma control, as measured by the ACT, asthma symptoms, and PEF variability.
ACT scores improved in 62% (n=26) of iG participants, and 39% (n=17) of RG participants, so the intervention effect assessed by risk difference (RD) for improved asthma control between groups was 0.233 (95% CI, 0.027-0.438; P =.032). The RD was 0.256 (95% CI, 0.048-0.463; P =.016) when adjusted for age, sex, body mass index, smoking, regular exercise at baseline, and ACT at baseline. When the intervention’s effects on individual asthma symptoms (wheezing, cough, shortness of breath, and phlegm) were analyzed, the reduction in shortness of breath was statistically significant (RD, 0.301; 95% CI, 0.109-0.492, P =.003), while changes in PEF variability were similar across both groups. Effect estimates were substantially greater for younger participants (RD 0.332; 95% CI, 0.059-0.624, P =.025) compared with older participants (RD, 0.069; 95% CI, −0.231 to 0.370; P =.653), elevated among women (RD, 0.294; 95% CI, 0.067–0.521; P =.015) with no effect evidence among men (RD −0.025; 95% CI, −0.478 to 0.428; P =.916), and a significant effect was seen in never smokers, but not current or previous smokers (RD, 0.334; 95% CI, 0.101–0.566; P =.009 vs RD, −0.089; 95% CI, −0.450 to 0.373; P =.334).
Study investigators concluded, “Our RCT provides evidence that 24 weeks of regular aerobic exercise with muscle training and stretching, improves asthma control measured by a broad spectrum of indicators, including reduction in use of rescue asthma medication, while it seems to have little effect on PEF variability. The a priori subgroup analyses suggest that the beneficial effects are most prominent among the young, women, and never smokers.”
Disclosure: This clinical trial was supported by grants from GlaxoSmithKline. Please see the original reference for a full list of authors’ disclosures.
Jaakkola JJK, Aalto SAM, Hernberg S, Kiihamäki SP, Jaakkola MS. Regular exercise improves asthma control in adults: A randomized controlled trial. Sci Rep. 2019;9(1):12088.