Chronic obstructive pulmonary disease (COPD) is a major health problem whose prevalence is increasing rapidly. The gradual decrease in exercise tolerance is one of the usual consequences of COPD that affects the functional independence and quality of life of patients.

In COPD patients, breathlessness and muscle fatigue are the main symptoms limiting exercise. Recent studies have shown that most of the physiological mechanisms of psychological factors such as emotions, motivation, memory, personality, expectations, or prior experience can greatly influence and modulate the perception of breathlessness. It has been proposed that the attentional distraction (visual or auditory) during exercise may be associated with a decrease in anxiety and shortness of breath and could improve exercise tolerance in COPD. We therefore propose to study the impact of attentional strategies of distraction on the perception of dyspnea and walking tolerance in patients with COPD.

The research hypotheses are:

i) Compared with exposure to a strategy of negative attentional distraction during exercise, exposure to a strategy of positive attentional distraction will improve walking exercise tolerance in patients with COPD;

ii) For a given level of effort, sensory perception and emotional perception will be enhanced by exposure to a strategy of positive attentional distraction.

Ten subjects with moderate to severe COPD will be recruited at the Research Center of the Institut Universitaire de cardiologie et de pneumologie de Québec (CRIUCPQ). During an assessment visit, we will measure complete pulmonary function, body composition and maximal functional capacity during a maximal incremental test work performed on a treadmill.

During two subsequent experimental visits, and after spirometry control, participants will perform a walking test performed on a treadmill at an intensity corresponding to 75% of maximum effort during maximal incremental test. The test will be carried out in combination with a strategy of either positive attentional distraction, neutral attentional distraction or negative attentional distraction . The order of the condition will be randomized.

Inclusion Criteria:

• Smoking history > 10 pack-years
• Post-BD FEV1 [30-80 % predicted value]
• Post-BD FEV1/FVC < 70 %
• Age [50-80 yrs]
• Voorips score < 9

Exclusion Criteria:

• Exacerbation < 4 weeks
• Asthma, Neoplasia, Cardiac failure, Diabetes
• Neuromuscular limitations
• Major depression or other psychiatric disorders
• BMI > 30 kg/m2
• PaO2 < 60 mmHg or oxygenotherapy
• Involvement in a structured and regular physical activity program