Free-living physical activity characteristics, activity-related air trapping and breathlessness, and utilization of...

Many patients with Chronic Obstructive Pulmonary Disease (COPD) experience air trapping at rest and during exercise. This study examined the relationship between air trapping and air hunger breathlessness during acute physical activity (PA) engagement. In addition, we examined free-living movement patterns of COPD patients, as well as their utilization of psycho-behavioral factors known to influence PA behavior.

Ten current or former smokers with COPD (M age=70 years) participated. Baseline pulmonary function measurements were gathered and participants completed a graded exercise test (2, 2.5, and 3 mph; 5 min each). At each stage, air hunger breathlessness was rated using the Multidimensional Dyspnea Profile (MDP). Inspiratory capacity (IC) measurements were also collected to monitor air trapping. Data regarding PA and sedentary behavior was measured over 7 days using accelerometry.

The results (mean [SD]) showed air trapping during exercise. IC levels across baseline and the 3 stages, respectively, were 1.66 (.62) L, 1.33 (.52) L, 1.35 (.58) L, and 1.28 (.57) L. A significant difference occurred between baseline and stage 1 (p=.01). Coincident low-to-moderate air-hunger breathlessness was observed across baseline and the 3 stages (Likert scale 0-10): 0.44 (1.01), 1.44 (2.12), 2.33 (2.59), and 2.67 (2.64). Participants utilized few PA-related psycho-behavioral strategies and spent the majority (67.4%) of their waking hours in sedentary behavior, while only engaging 5 min a day of moderate intensity PA and 0 min at vigorous-intensity PA.

These COPD patients were intolerant to low levels of exercise intensity, resulting in little PA engagement, and also utilized few PA-related psycho-behavioral strategies.