Inclusion difficulties (44/100 patients) despite a 24-month extension. The population often presents with 2 concomitant diseases.

Many exercise tests are commonly used to evaluate the changes of exercise tolerance following rehabilitation programs in patients with chronic respiratory diseases.

Among the tests (6-MWT, incremental test, ...), the literature seems to indicate that endurance time is the most responsive parameter for detecting and quantifying changes in exercise capacity following a rehabilitation program. Although its clinical interest is undeniable, the endurance shuttle walking test is rarely used because it requires the prior performance of two incremental shuttle walking tests to determine the walking speed imposed on the patient.

In this protocol, we propose to test a Walk-Time Limit Test (WTLT) derived from the 6-minute walk test (6-MWT) and based on the average walking speed achieved in this test commonly used in the follow-up of patients with chronic diseases.

TTLM validation would improve the functional assessment of patients with chronic diseases while limiting the number of exercise tests.

Each patient will perform 4 visits over a period of 4-week. Fifty subjects with COPD and fifty subjects with heart failure will be recruited for the same protocol.

During the first visit, the subject will realize two 6-MWT and a cardiopulmonary exercise test on ergocycle with the measure of cardiorespiratory parameters. We will evaluate the physical activity during daily life using an accelerometer and we will use several questionnaires to measure the quality of life, the motivation to physical activities and symptoms.

During the second visit, the subject will realize a 4-meter walk test, two incremental shuttle walk tests (ISWT), an endurance shuttle walk test (ESWT) and a test with dynamometer to measure the quadriceps strength.

During the third and fourth visits, the subject realize two or three endurance walking tests (Walk-Time Limit Test - WTLT) at a walking speed equivalent to the mean speed realize during the better 6MWT (visit 1)

Inclusion Criteria:

• Chronic Respiratory Disease Group:

  • Diagnosis of COPD with FEV1 corresponding to stages GOLD II or III (50-80% predicted or 30-50% predicted, respectively).
  • Patient's agreement
  • Being older than 18
  • Stable treatment for 3 months
  • Subjects affiliated with social security

• Group cardiovascular diseases:

  • Diagnosis of heart failure or stable coronary artery disease with NYHA Class II stage.
  • Patient's agreement
  • Being older than 18
  • Stable treatment for 3 months
  • Subjects affiliated with social security

Exclusion Criteria:

• Any medical contraindications to the practice of a suitable physical activity
• Presence of muscle, joint and / or neurological comorbidities affecting motor skills and test performance.
• Refusal of the patient
• Subject under guardianship or curatorship
• Subject aged over 80 at the time of inclusion
• Realization of a rehabilitation program during the study period
• Subject under resting oxygen therapy
• Diagnosis of heart failure, coronary artery disease or any cardiovascular pathology that required surgery.
• Diagnosis of an associated chronic respiratory disease, such as asthma, pulmonary arterial hypertension or interstitial lung disease.

All collected data that underlie results in a publication

Data will be available beginning three years and ending fifteen years following the final study report completion

Data access requests will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement.