Obstructive sleep apnea (OSA) is characterized by complete or partial upper-airway collapse during sleep associated with sleepiness. OSA causes severe impairments in quality of life (sleepiness, tiredness, concentration difficulties). Moreover, OSA has adverse consequences on the cardiovascular system by causing intermittent hypoxia, increased sympathetic nervous system activation and vascular endothelial dysfunction.

Continuous Positive Airway Pressure (CPAP) and mandibular advanced devices (MAD) remain the two first-line therapies for OSA. However, not all patients are eligible for these treatments or are not able to follow for a lifelong therapy and therefore do not use it consistently.

A recent meta-analysis has confirmed that regular physical activity reduces OSA by approximately 28% (Mendelson et al. 2018). However, an important inter-individual variability exists and no study to date has identified characteristics of patients who respond to these interventions.

The aim of this Prospective study, single-site, non-randomized 4-week trial is to evaluate the impact of a 4-week physical activity intervention on the apnea-hypopnea index (AHI) in OSA patients based on their baseline fluid shift level.

Participants included in the present study will benefit from a 4-week physical activity intervention. Upon the initial visit, a physical activity prescription will be defined and they will be equipped with a physical activity monitor that allows feedback. Participants will then exercise one day per week on-site and 4 days/week on their own. Weekly physical activity will be reviewed weekly with the participant during their on-site visit.

Inclusion Criteria:

• • Patient aged 18 to 80 years old

  • Patient with OSA (AHI ≥ 15 events/hr)
  • Patient not receiving any treatment for their OSA
  • Patient able to provide written informed consent
  • Patient able to participate in regular physical activity (no medical contraindication to exercise)

Exclusion Criteria:

• • Pregnancy

  • Person deprived of liberty or subject to a legal protection measure
  • Patient presenting a condition that can influence the results. (According to the investigator's judgment, i.e. heart failure, venous insufficiency).
  • Vulnerable person or legally protected adult.
  • Patients already included in another interventional study
  • BMI > 30 kg/m²
  • Patient taking diuretics