The COVID-19 infection, which is considered as a pandemic by the World Health Organization, affects the whole world. COVID-19 is an infectious respiratory disease caused by SARS-CoV-2. It is stated in early studies that after COVID-19 infection, there are adverse effects on both the peripheral and respiratory muscles along with the pulmonary system involvement. The purpose of our study; To examine the effect of Inspiratory Muscle Training (IMT) on respiratory muscle strength, respiratory functions and functional capacity in PostCOVID-19 patients. Patients who have been hospitalized and discharged with the diagnosis of COVID-19 in Istinye University hospitals, at least 6 weeks have passed since the infection, the PCR test has turned negative will be taken. The evaluation and treatment of the patients will be carried out in the Education and Research Units of Istinye University Physiotherapy and Rehabilitation Department. Patients included in the study will be randomly divided into two groups, study and control groups. Demographic evaluation form, Post Covid Functional Status Scale, Charlson Comorbidity Index, Modified Medical Research Council (MMRC) Dyspnea scale, Corbin posture analysis, Respiratory function test, Respiratory muscle strength measurement, Respiratory Muscle Endurance measurement, 6-minute walking test (6 MWT) ), Peripheral Muscle Strength, Grip Strength, Hospital Anxiety and Depression Scale (HADS), Breathlessness Perception Questionnaire (BBQ) and Nottingham Health Profile Questionnaire will be used. In the study group, IMT will be applied at 40% of the maximum inspiratory pressure (MIP) for eight weeks, every day of the week, twice a day for 15 minutes. The patients will come for a control once a week, the MIP values will be measured again and the new training intensity will be determined at 40% of the new MIP value. The control group will be given a constant training of 15 minutes at 10% of the MIP, twice a day, every day of the week for eight weeks. Evaluations of the study and control groups will be made at the beginning and after eight weeks.

Inclusion Criteria:

• Adults ages 18-70
• Being clinically stable,
• Having COVID-19 infection and at least 6 weeks after infection
• Being between Grade 2-4 according to Post-COVID Functional Status Scale
• Regular participation in treatment
• To read, write and understand Turkish
• Volunteering to participate in research

Exclusion Criteria:

• Presence of mental and cognitive impairments
• Having an orthopedic, neurological disease that prevents exercise
• Uncontrolled hypertension, having a cardiovascular disease
• Pregnancy and breastfeeding