Matched placebo granules. This preparation is specifically designed to be indistinguishable from the active "Huangjing Yangji Formula Granules" in terms of appearance, color, odor, packaging, and solubility. It contains no pharmacologically active herbal components. Administered orally in the same manner (twice daily, 30 minutes after meals) for 3 months.

A structured, progressive resistance training program using elastic bands. Participants train 3 times per week for 3 months. Each 60-minute session includes warm-up, 10 core strength exercises (e.g., standing row, leg extension, bridge), and cool-down. Intensity is progressively increased from low (approximately 40-60% of 1-RM) to medium-high (approximately 60-80% of 1-RM) resistance. Sessions are supervised once weekly, with twice-weekly home-based sessions.

Time (in seconds) required to stand up from a standard armchair, walk 3 meters at a usual pace, turn around, walk back, and sit down again. The test is performed twice, and the shorter time of the two trials is recorded. It is a widely used measure of functional mobility and fall risk.

Maximal isometric strength of the dominant hand, measured in kilograms (kg) using a handheld dynamometer (handgrip). The participant is seated with the forearm supported. Three trials are performed, and the highest value is recorded as the outcome. It is a standard measure of overall muscle strength.

Total score on the POMA, a standardized tool to assess balance and walking ability. It consists of a Balance subscale (9 items, score 0-16) and a Gait subscale (7 items, score 0-12). The total score ranges from 0 to 28, with a higher score indicating better mobility and lower fall risk. Scores are interpreted as: ≤18 (high fall risk), 19-24 (moderate fall risk), ≥25 (low fall risk).

The appendicular skeletal muscle mass (sum of muscle mass in both arms and legs) measured in kilograms (kg) using a multi-frequency BIA device (InBody 770C), divided by the square of height in meters to yield ASMI in kg/m².

Lean body mass measured in kilograms (kg) using a multi-frequency bioelectrical impedance analysis (BIA) device (InBody 770C).

Fat mass measured in kilograms (kg) using a multi-frequency bioelectrical impedance analysis (BIA) device (InBody 770C).

Body fat percentage measured in percent (%) using a multi-frequency bioelectrical impedance analysis (BIA) device (InBody 770C).

Body Mass Index calculated as weight in kilograms divided by height in meters squared (kg/m²). Weight and height are obtained using a multi-frequency bioelectrical impedance analysis (BIA) device (InBody 770C).

Total score on the FRAIL scale, a brief screening tool based on the frailty phenotype. It assesses five components: Fatigue, Resistance (difficulty climbing stairs), Ambulation (difficulty walking), Illnesses (number of comorbidities), and Loss of weight. Each component present scores 1 point. Total scores range from 0 to 5 and are interpreted as: 0 (robust/no frailty), 1-2 (pre-frail), and ≥3 (frail).

Total score on the Barthel Index, a measure of independence in performing basic activities of daily living (ADL). It assesses 10 items: feeding, bathing, grooming, dressing, bowel control, bladder control, toilet use, bed-chair transfer, ambulation, and stair climbing. Each item is scored 0, 5, 10, or 15 based on the level of assistance required. Total scores range from 0 to 100 and are interpreted as: 0-20 (total dependence), 25-45 (severe dependence), 50-70 (moderate dependence), 75-95 (mild dependence), 100 (complete independence).

Total score on the 30-item GDS, a self-report measure designed specifically to assess depressive symptoms, focusing on mood and cognition while minimizing somatic items. Scores range from 0 to 30. A total score of ≥11 indicates the presence of depressive symptoms, with scores of 11-20 suggesting mild depression and scores of 21-30 suggesting moderate to severe depression.

Total score on the MNA-SF, a 6-item screening tool used to assess nutritional status or risk of malnutrition. Total scores range from 0 to 14 and are interpreted as: 12-14 (normal nutritional status), 8-11 (at risk of malnutrition), and 0-7 (malnourished).

Global score on the PSQI, a 19-item self-rated questionnaire assessing sleep quality and disturbances over the past month. The score encompasses seven components. Total scores range from 0 to 21, interpreted as: 0-5 (good sleep quality), 6-10 (mild sleep disturbance), 11-15 (moderate sleep disturbance), and 16-21 (severe sleep disturbance).

Scores on the SF-12, a shortened version of the SF-36 used to efficiently assess health-related quality of life. It yields two summary scores: the Physical Component Summary (PCS) and the Mental Component Summary (MCS). Both are standardized scores, with higher values indicating better physical or mental health-related quality of life.

Fasting venous blood samples will be collected, processed within 30 minutes, and stored for batch analysis. Levels of the following biomarkers will be quantified using standard methods: inflammatory markers (Tumor Necrosis Factor-alpha, Interleukin-6, Interleukin-1beta), muscle metabolism markers (Irisin, Myostatin), and metabolic hormones (25-Hydroxyvitamin D, Insulin-like Growth Factor-1, Growth Hormone).

The TCM syndrome score is assessed according to the《Guiding Principles for Clinical Research of New Chinese Medicines》. It evaluates three primary symptoms (muscle wasting, general fatigue, soreness and weakness of the lower back) and five secondary symptoms (poor appetite, abdominal distension, loose stools, dizziness, forgetfulness). Primary symptoms are scored 0 (none), 2 (mild), 4 (moderate), or 6 (severe); secondary symptoms are scored 0 (none), 1 (mild), 2 (moderate), or 3 (severe). The total score is the sum of all items, with a higher score indicating more severe symptoms. Efficacy is categorized based on the percentage reduction in the total score after treatment: ≥70% (markedly effective), 30-69% (effective), <30% (ineffective).