Effects of Exercise training on Patients With Long COVID-19, is a single-center, randomized, controlled trial designed to evaluate the effects of 4- week aerobic exercise administered to patients with long COVID-19 symptoms. The main outcome is cardiopulmonary fitness and long COVID-19 symptom improvement. Quality of life, depression, anxiety, insomnia status and perceived stress will also be assessed before and after the exercise program.

Long COVID-19 symptoms are characterized by systemic deterioration of the entire body, leading to significant physiological and functional imbalances. Common symptoms may be related to decreased short-term or long-term exercise capacity resulting from organ tissue damage, such as myocardial and pulmonary dysfunction. Currently, even vaccines and medications cannot effectively address the long-term consequences of COVID-19. Exercise training has been proven to improve exercise capacity and quality of life during the recovery period for various chronic disease patients.

A total of 24 patients will be included in the study. Following informed consent and baseline testing, the participants will be randomized in a 1:1 fashion to receive a 4-week aerobic exercise training or attention control.The main objective is to assess the effects of a 4-week aerobic exercise training program on cardiopulmonary fitness and long COVID-19 symptom improvement. Secondary objectives include: to characterize baseline and intervention-related changes in quality of life, depression, anxiety, insomnia status and perceived stress status.

Inclusion Criteria:

1. 18-75 years old;
2. Complicated with at least one of the following symptoms within 3 months after COVID-19 infection, lasts for at least 2 months, and is not caused by other diseases: Cough, fatigue, memory loss, concentration problems, palpitation easily or rapid heartbeat, chest tightness or chest pain, pain (head, limbs, lower back), slow thinking or reaction, eye discomfort or decreased vision, shortness of breath or difficulty breathing at rest, diarrhea, loss of taste or decreased taste, insomnia, hair loss, other new symptoms after COVID-19 infection
3. Tested positive for COVID-19 quantitative Reverse Transcription-Polymerase Chain Reaction (RT-PCR) or antigen kit and turned negative for at least 4 weeks before inclusion;
4. The patient understands and signs the informed consent form.

Exclusion Criteria:

1. Infected with COVID-19 within one month
2. Conditions that may be worsened by exercise, such as acute cardiac insufficiency, exercise asthma, epilepsy, etc.
3. Physical disabilities caused by bone and joint or neuromuscular diseases,
4. Complicated with other serious diseases (such as unstable angina, resting oxygen saturation < 93%, untreated heart failure, uncontrolled arrhythmia, uncontrolled hypertension, uncontrolled type 2 diabetes),
5. Women during pregnancy and lactation;
6. Patients was assessed unsuitable for this study.