Abstract

Objective: To compare the 12-week effects of continuous high-intensity training (CTHI), continuous training at the ventilatory threshold (CTVT) and high-intensity interval training (HIIT) on cognition, and the 1-year maintenance of these effects in people with COPD.

Methods: Participants were randomized to CTHI, CTVT, or HIIT and underwent 12 weeks of three times weekly training on cycle ergometers. The intensity phase included 25 minutes of pedaling at 80% of peak wattage (Wpeak) for CTHI. For CTVT, the intensity was set at the ventilatory threshold, while HIIT consisted of 30-second intervals at 100% of Wpeak alternated with unloaded pedaling. Session duration for CTVT and HIIT was calculated to ensure comparable total work as for CTHI. Assessments were made at baseline (week 0), program completion (week 12) and 1 year after baseline (year 1). Cognition was assessed with a neuropsychological testing battery. Global cognitive function was assessed using the Montreal Cognitive Assessment (MoCA).

Results: Thirty-six participants (64% women, mean age: 67.5±9 years) with moderate COPD were randomized. The 12-week effects of exercise training on cognition were small or very small, except for visuospatial abilities, which detected larger effects especially in participants with mild cognitive impairment at baseline. There was considerable heterogeneity between intervention groups. CTHI was the only group with medium-to-large effects in each cognitive domain assessed. At year 1, gains and losses in cognition were seen in all groups.

Conclusion: In COPD, 12 weeks of training led to small changes in cognition, with notable heterogeneity between exercise protocols and across cognitive domains.