• Arm Description: Participants in this group will engage in a 12-week multimodal exercise program. The program includes supervised training sessions, home-based exercises, and digital support. They will also receive a "Diabetes and Muscle Health Handbook" to guide their training.

Participants in this group will serve as the control. They will receive a "Nutrition and Muscle Health Education Sheet" at the beginning of the study. They will not participate in the multimodal exercise program and will continue with their routine health management based on existing medical advice.

Participants will engage in a 12-week multimodal exercise program comprising supervised training sessions, home-based exercises, and digital support. To facilitate adherence and proper technique, participants will also receive a "Diabetes and Muscle Health Handbook" as a training guide.

The Five-Times Sit-to-Stand Test (5TSTS) assesses lower limb muscle power. Participants are asked to stand up and sit down five times as quickly as possible with arms folded. The time to completion is recorded in seconds and analyzed as a continuous variable. According to the 2019 Asian Working Group for Sarcopenia (AWGS) consensus, a completion time of ≥ 12 seconds is considered abnormal and indicates low physical performance.

Handgrip strength (HGS) is assessed using a digital dynamometer (e.g., Jamar or an equivalent device). During the assessment, participants stand with their testing arm fully extended. Two consecutive trials are performed for each hand, and the maximum grip strength value (in kilograms) is selected for data analysis. Based on the 2019 Asian Working Group for Sarcopenia (AWGS) consensus, low muscle strength is defined as < 28 kg for men and < 18 kg for women

Determined by bioelectrical impedance analysis (BIA). Appendicular skeletal muscle mass (ASM, kg) is calculated as the sum of lean mass from both arms and legs. SMI is expressed as ASM divided by height squared (kg/m²). Low muscle mass is defined according to AWGS 2019 cut-off values (<7.0 kg/m² for men and <5.7 kg/m² for women).

Assessed using the Strength, Assistance with walking, Rise from a chair, Climb stairs, and Falls (SARC-F) questionnaire combined with calf circumference measurement (SARC-CalF). The SARC-F assesses 5 items scored 0-10. A calf circumference ≤34 cm (men) or ≤33 cm (women) adds 10 points. Total SARC-CalF scores range from 0 to 20. Higher scores indicate a higher risk of sarcopenia (a worse outcome). A total SARC-CalF score ≥11 indicates a high risk.

Metabolic control is evaluated by HbA1c levels. Venous blood samples are collected after an overnight fast and analyzed using standardized high-performance liquid chromatography (HPLC). Values are reported as percentages. According to the American Diabetes Association (ADA) guidelines, the target HbA1c level for patients with type 2 diabetes mellitus (T2DM) is < 7.0%.