Muscle Metabolism and Oxygenation During Localized Fatigue-exercise in COPD

Muscle Oxygenation and Metabolism in Response to a Localized Fatigue-inducing Exercise in Patients With Chronic Obstructive Pulmonary Disease

The purpose of this study is to investigate whether a localized exercise, in which cardiorespiratory demand is reduced, will result in greater limb muscle fatigue in patients with COPD as a consequence of muscle oxygenation and muscle metabolism disturbances.

Inclusion Criteria:

• COPD (FEV1/FVC < 0.70 and FEV1 < 0.80 predicted
• Healthy subjects: no evidence of airways obstruction (FEV1/FVC > 0.70 and FEV1 > 0.80 predicted)
• Smoking history > 15 pack-years

Exclusion Criteria:

• Chronic hypoxemia and/or hypercapnia (PaO2 < 60 mmHg or SpO2 < 88% at rest and/or PaCO2 > 45 mmHg)
• Recent exacerbation (< 3 months)
• Recent cancer (< 3 years)
• Diabetes
• Myopathy, neuromuscular or articular disease
• Unstable cardiac disease
• Absolute contraindications to exercise testing
• Regular physical activity or exercise training program in the last 2 months
• Physical activity score > 9 in the Voorips questionnaire
• Thigh skinfold thickness > 15 mm
• BMI > 30