In this study respiratory and submental muscle activities during during inspiratory and expiratory breathing maneuver at specific workloads will be assessed according to inspiratory and expiratory muscle strength of each obstructive sleep apnea syndrome (OSAS) patient's.

Recurrent upper airway obstruction, apnea-hypopnea events, arousals and asphyxia during sleep increase the respiratory workload in patients with OSAS. This results in chronic overload of the inspiratory muscles -especially the diaphragm- and respiratory muscle fatigue in OSAS. When the literature was checked, there was no study assessing and comparing the activities of M. genioglossus, submental muscles (upper airways dilator muscles) and diaphragm during inspiration and expiration in a workload. Differences in the activity of these muscles according to the type of respiratory maneuver will provide more appropriate respiratory muscle training in patients.

Inclusion Criteria:

• Between 35-70 years old
• Diagnosed with mild-moderate OSAS
• Clinically stabile

Exclusion Criteria:

• Anatomical obstructive upper airway
• Occupations that lead to sleep deprivation or alterations in the sleep-wake cycle.
• Comorbidities such as chronic obstructive pulmonary disease, asthma, interstitial lung diseases, neuromuscular diseases and psychiatric diseases

Patients with OSAS who will be referred to the Cardiopulmonary Rehabilitation Unit of the Faculty of Physical Therapy and Rehabilitation of Hacettepe University by Dışkapı Yıldırım Beyazıt Educational and Research Hospital Department of Chest Diseases will be included in this study.