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

The therapeutic effects of exercise have 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 randomized controlled trial in 46 adults with asthma randomized to either (1) 45-minute moderate-intensity exercise training 3 times/wk, (2) 30-minute vigorous-intensity exercise training 3 times/wk, or (3) the control group. Asthma-related quality of life (AQLQ), asthma control (ACQ), cardiorespiratory fitness, body composition, and airway and systemic inflammation were assessed before and after the intervention.

Forty-one participants completed the study (89% retention). The moderate-intensity group had a statistically and clinically significant improvement in AQLQ (0.63 [0.33-0.93], P < .001) and ACQ (-0.51 [-0.83 to -0.19], P = .003) relative to control. The vigorous-intensity group had a statistically, but not clinically, significant improvement in AQLQ (0.46 [0.14-0.80], P = .007) and ACQ (-0.36 [-0.69 to -0.02], P = .040) relative to control. After moderate-intensity training, there was a reduction in sputum macrophage (-1341 [-2491 to -191] × 10⁴/mL, P = .024) and lymphocyte (-114 [-220 to -8] × 10⁴/mL, P = .036) counts relative to control. A reduction in android fat mass, but not a change in fitness, was associated with improved AQLQ (r_s = -0.341, P = .030) and reduced sputum IL-6 (r_s = 0.422, P = .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.