The study was designed to test the following hypothesis

Patients with high cardio-respiratory response to electrostimulation (ES), high perception of pain during ES and high ES-induced muscle fatigue, have low tolerance to ES (more difficulties to increase intensity during training).

Background: Muscle electrostimulation (ES) appears as a promising alternative to general physical reconditioning in advanced COPD and its feasibility has been confirmed in this population. However, patients are not equal in tolerance to ES. Certain patients are not able to increase ES intensity during training, limiting its benefits. Furthermore, little is known about the effect of one ES training session on cardio-respiratory response, muscle fatigue and systemic inflammation in COPD patients.

Objective: To evaluate the tolerance to ES in COPD patients and to identify the physiological parameters involved in ES tolerance.

Method: We propose to conduct a prospective study including 21 COPD patients of different pulmonary severity (7 in each group of GOLD II, III and IV). Patients will be evaluated 3 times: at day 1, day 2 and day 9. In the first session, patients will be initiated to ES and evaluated in walking distance. In the second session, patients will become autonomous with ES and they will be evaluated in muscle strength and body composition. In the third session, cardio-respiratory measurements will be performed during ES and patients will be evaluated in muscle strength and systemic inflammation (blood sampling) before and after ES. Between the 2d and the 3d sessions, patients will have to perform 5 ES sessions at home (from day 3 to day 8). Tolerance (symptoms assessed with visual analogical scale (VAS)) and intensity of ES will be measured during each ES session.

Planning analysis: The main outcome will be the change in ES intensity between session 2 and 3 (delta intensity). The other end-points will be minute ventilation, heart rate, VO2 and SaO2 during ES, but also change in ES tolerance (VAS) during ES at equal ES intensity, leg muscle fatigue after ES, body composition and changes in plasmatic proteins after ES. Simple and multiple regressions analysis will be done between delta intensity and 1/cardio-respiratory response during ES, 2/muscle fatigue after ES, 3/body composition, 4/perception of pain at session 2 (VAS), 5/changes in plasmatic proteins after ES.

Inclusion Criteria:

• Subject is diagnosed with COPD.
• 40 years-old and older
• Currently or previously smoking with a smoking history of at least 10 pack-years
• Subject understands and is able to read and write French or English

Exclusion Criteria:

• absence of neuromuscular pathology
• absence of vascular pathology
• absence of dermatosis on legs