Effects of Moderate- Versus Vigorous-Intensity Exercise Training on Asthma Outcomes in Adults

Abstract

The therapeutic effects of exercise has prompted calls for it to be embedded into standard asthma care, but evidence informing the optimal exercise intensity is lacking. This study aimed to compare the effects of moderate- and vigorous-intensity aerobic exercise training on asthma outcomes and inflammation. This was a 12-week randomised controlled trial in 46 adults with asthma randomised to either 1) 45min moderate-intensity exercise training three times/week, 2) 30min vigorous-intensity exercise training three times/week, or 3) control group. Asthma-related quality of life (AQLQ), asthma control (ACQ), cardiorespiratory fitness, body composition, and airway and systemic inflammation were assessed pre- and post-intervention. Forty-one participants completed the study (89% retention). The moderate-intensity group had a statistically and clinically significant improvement in AQLQ [0.63 (0.33 to 0.93) p<0.001) and ACQ [-0.51 (-0.83 to -0.19), p=0.003] relative to control. The vigorous-intensity group had a statistically, but not clinically, significant improvement in AQLQ [0.46 (0.14 to 0.80, p=0.007] and ACQ [-0.36 (-0.69 to -0.02, p=0.040] relative to control. Following moderate-intensity training, there was a reduction in sputum macrophage [-1341 (-2491 to -191)x104/mL, p=0.024] and lymphocyte [-114 (-220 to -8)x104/mL, p=0.036] counts relative to control. A reduction in android fat mass, but not a change in fitness, was associated with improved AQLQ (rs=-0.341, p=0.030) and reduced sputum IL-6 (rs=0.422, p=0.013). Our findings suggest that both moderate-intensity and vigorous-intensity aerobic exercise training are associated with improvements in clinical asthma outcomes, and therefore both intensities could be recommended as an adjuvant asthma therapy.