Inclusion Criteria:  COPD patients GOLD stage 2 and 3 (A-D) In accordance with Article L1121-8-1 of the Public Health Code, participants must be affiliated to a social security scheme or benefit from such a scheme.  Exclusion Criteria:  the presence of long-term or exercise-based oxygen therapy, the presence of a medically diagnosed pathology causing manifest disorders of balance, the inability to walk 150 m without stopping and to climb or descend stairs, a history of pneumonectomy or lobectomy within the last six months, the existence of an acute respiratory exacerbation within the last two months, the presence of obvious cognitive impairment that impairs comprehension of instructions, body mass index less than 21 or more than 35 kg/m².  Person referred to in articles L. 1121-5 to L. 1121-8 and L. 1121-12 of the public health code:  Pregnant woman, woman in labour or nursing mother Person deprived of liberty by judicial or administrative decision Person hospitalised without consent and not subject to a legal protection measure, and person admitted to a health or social establishment for purposes other than research Minor Person subject to a period of exclusion for other research Person of full age subject to a legal protection measure (guardianship, curatorship or safeguard of justice), person of full age unable to express their consent and not subject to a protection measure Person under psychiatric care