The Effects of the Yi Jin Jing on the Muscles and Bones of Adults

Inclusion Criteria: * Age 18-90 years inclusive; * Generally healthy, no acute or chronic diseases affecting major organ functions; * No cognitive impairment, able to understand and comply with study procedures; * Willing and able to provide written informed consent; * No pregnancy or lactation (for females); * No recent (within 3 months) major surgery, hospitalization, or significant weight change (\>5% body weight). Exclusion Criteria: * Presence of acute or unstable chronic diseases (e.g., uncontrolled hypertension, diabetes, heart failure, or malignancy); * Severe cognitive impairment, psychiatric disorders, or inability to follow study instructions; * Recent (≤3 months) major surgery, trauma, or hospitalization; * Pregnancy, lactation, or childbearing potential without reliable contraception; * Body mass index (BMI) \<16 or \>40 kg/m²; * Current use of medications affecting muscle or nutritional metabolism (e.g., corticosteroids, anabolic steroids); * Participation in another interventional trial within 30 days.