The goal of this clinical trial is to learn if a structured early exercise program can help patients recover better in people who have just had coronary artery bypass surgery. The main questions it aims to answer are:

• Does this early exercise improve fitness and walking ability?
• Does it reduce the risk of muscle weakness (sarcopenia) after surgery?
• Does it improve patients' quality of life?
• Does it reduce feelings of anxiety and depression? Researchers will compare the group receiving the structured early exercise program (plus standard hospital care) to the group receiving standard hospital care only to see if the early exercise program leads to better and faster recovery.

Participants in the exercise group will:

• Start supervised exercise sessions within 24 hours after their surgery.
• Perform these sessions twice a day for 30 minutes each, for 5 days.
• The exercises include warm-ups, breathing exercises, walking or stationary cycling, and light resistance training.

Inclusion Criteria:

• age between 40 and 85 years;
• undergoing first-time CABG surgery;
• no diagnosed psychiatric disorders or musculoskeletal diseases and did not require any assistive mobility devices;
• ability to communicate in Mandarin or Taiwanese;
• agreed to participate and provided written informed consent after receiving a comprehensive explanation of this trial.

Exclusion Criteria:

• preoperative use of continuous 24-hour nitroglycerin infusion or inotropic agents;
• undergoing emergency cardiac surgery or requiring admission to the intensive care unit preoperatively;
• occurrence of major intraoperative complications (e.g., major hemorrhage, stroke, requirement for resuscitation, or severe delirium).

De-identified individual participant data (IPD) that underlie the results reported in the final publication will be made available. The study protocol will also be available.

Data will be available beginning 6 months after the publication of the primary manuscript and will remain available for 5 years.

Data access will be granted to qualified academic researchers for legitimate research purposes, such as re-analysis or meta-analysis. Researchers must submit a methodologically sound proposal to the corresponding author. Upon approval by the principal investigators and the Institutional Review Board, and contingent upon the terms of the original informed consent, de-identified Individual Participant Data that underlie the results reported in the final publication (including main dataset and analytic code) will be shared. A signed data-use agreement will be required prior to data release to ensure participant confidentiality.