Clinical Research Directory

Inclusion Criteria: * Detailed medical history taken, with no symptoms of discomfort reported * Good physical condition, with no history of severe chronic diseases * No history of long - term medication use * Willing to undergo cardiopulmonary exercise testing, with no ST - T segment changes observed during the test * Age: 18 - 65 years old * BMI: 18.5 - 28kg/m² * No smoking history or quit smoking for ≥5 years * Physical examination reports within 2 years show no significant abnormalities. Exclusion Criteria: * Pre - test resting blood pressure ≥160/100 mmHg (1 mmHg=0.133 kPa) * Chronic cardiovascular diseases, such as heart failure, coronary atherosclerotic heart disease, hypertension, congenital heart disease, cardiomyopathy, and severe arrhythmias * Respiratory diseases, such as chronic obstructive pulmonary disease, asthma, pulmonary artery hypertension, bronchiectasis, and respiratory failure * Digestive system diseases, such as peptic ulcer, gastrointestinal bleeding, hepatitis, liver cirrhosis, ulcerative colitis, Crohn's disease, chronic pancreatitis, and chronic cholecystitis * Endocrine system diseases, such as hyperthyroidism, hypothyroidism, diabetes, and other diseases with clear hormone abnormalities * Acute or chronic kidney diseases, blood system diseases, malignant tumors, and bone and joint diseases that affect activity * No history of acute infection within 2 weeks * Unable to cooperate with the examination * Contraindications to cardiopulmonary exercise testing: acute myocardial infarction