Participants will perform supervised aerobic high-intensity interval training combined with resistance training. Aerobic training is performed on a cycle ergometer and consists of four sets of 4-minute work intervals at 80-95% of VO₂peak, interspersed with 3-minute recovery intervals at 60% of VO₂peak. Each session includes a 3-minute warm-up and a 3-minute cool-down, for a total duration of 34 minutes per session. Exercise is performed three times per week for eight weeks. Resistance training includes chest press, leg extension, leg press, and abdominal exercises using pneumatic resistance machines (HUR, Finland), consisting of two sets of 20-25 repetitions at approximately 20RM. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the intervention period.

Participants will perform supervised low-intensity continuous training combined with resistance training and nutritional counseling. Aerobic training is performed on a cycle ergometer at 37-45% of VO₂peak for 28 minutes per session, with a 3-minute warm-up and a 3-minute cool-down, for a total duration of 34 minutes. Exercise is performed three times per week for eight weeks. Resistance training includes chest press, leg extension, leg press, and abdominal exercises using pneumatic resistance machines (HUR, Finland), consisting of two sets of 20-25 repetitions at approximately 20RM. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the intervention period.

Participants will receive usual postoperative care without structured exercise intervention. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the study period.

Supervised aerobic high-intensity interval training combined with resistance training and nutritional counseling. Aerobic training is performed on a cycle ergometer and consists of four sets of 4-minute high-intensity intervals at 80-95% of VO₂peak, interspersed with 3-minute recovery periods at 60% of VO₂peak. Each session includes a 3-minute warm-up and a 3-minute cool-down, with a total duration of 34 minutes. Training is performed three times per week for eight weeks. Resistance training includes chest press, leg extension, leg press, and abdominal exercises using pneumatic resistance machines, consisting of two sets of 20-25 repetitions at approximately 20RM. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the intervention period.

Cardiorespiratory fitness will be assessed using symptom-limited cardiopulmonary exercise testing (CPET) on a cycle ergometer under medical supervision with continuous breath-by-breath gas analysis. After a 4-minute unloaded warm-up, workload is increased by 10-20 W/min depending on patient condition, with participants cycling at 50 rpm until volitional exhaustion. The test is terminated when cadence falls below 40 rpm, at physician discretion, or at patient exhaustion, followed by a 2-minute cool-down at 20 W. Continuous 12-lead ECG, blood pressure, and oxygen saturation are monitored during testing. VO₂peak is defined as the highest 30-second averaged oxygen uptake immediately prior to exhaustion. Peak workload, peak heart rate, and oxygen uptake at ventilatory threshold are also recorded.

Handgrip strength will be measured using a standard adjustable-handle dynamometer (InGrip, InBody Japan Inc., Tokyo, Japan). Measurements will be performed in a standing position with arms at the side. Two maximal voluntary efforts will be recorded for each hand, and the highest value will be used (kg) as the outcome measure.