Telehealth exercise training for 12 weeks

usual outpatient care for 12 weeks

Each participant received an individual exercise counselling session lasting 10-15 minutes, based on the guidelines of the American College of Sports Medicine.

Participants in the home-based telehealth exercise group were provided with a mobile exercise application integrated with heart rate-monitoring clothing. The app delivers real-time heart rate feedback during each session and includes an alert system to ensure participants maintain their prescribed target heart rate based on individualized exercise prescriptions. Upon completion of each session, exercise duration and heart rate data are automatically uploaded to the medical center's cloud system via the monitoring device.

An experienced nurse regularly reviewed the cloud-based data to monitor adherence. Additionally, communication between participants and researchers was facilitated through the LINE platform, enabling timely interaction and support.

Common long COVID symptoms, based on the participants' subjective reports, include fatigue, shortness of breath, cough, chest pain, palpitations, brain fog, headaches, sleep disturbances, dizziness, changes in taste or smell, and depression or anxiety; these were assessed by a physician using a checklist with a binary response (present or absent).

Participants will undergo cardiopulmonary exercise testing using a motorized cycle ergometer with an incremental ramp protocol (10 W/min). The test will continue until participants report physical exhaustion or reach maximal exercise capacity, defined by respiratory exchange ratio criteria. Peak oxygen uptake (VO₂peak, mL/kg/min) will be estimated from maximal cardiac output and oxygen utilization and identified when oxygen consumption plateaus despite increasing exercise intensity.

Unit of Measure: mL/kg/min

During cardiopulmonary exercise testing, peak workload (watts) will be recorded as the highest workload achieved on the cycle ergometer. This reflects participants' ability to tolerate increasing exercise intensity.

Unit of Measure: watts

Anaerobic threshold (AT, mL/kg/min) will be determined during cardiopulmonary exercise testing as the point at which energy production begins to shift from aerobic to anaerobic metabolism.

Unit of Measure: mL/kg/min

The brief World Health Organization Quality of Life questionnaire includes 26 standardized items covering four domains: physical, psychological, social, and environmental. It also contains two general items assessing overall quality of life and general health. The Taiwanese version adds two culturally specific items related to social respect/acceptance and eating/food.

All items are rated on a 5-point Likert scale, where higher scores reflect better quality of life. Scores for each domain are calculated by averaging the item scores within that domain and then multiplying by 4, yielding a final score range from 4 to 20.

Adverse events were monitored throughout the 12-week intervention. They were defined as any unfavorable or unintended signs, symptoms, or medical conditions occurring during the study that were considered related or possibly related to the intervention and required medical attention, discontinuation of exercise, or modification of the intervention.

Mild and transient exercise-related responses, such as expected fatigue or delayed-onset muscle soreness that resolved without medical intervention, were not classified as adverse events, in accordance with standard exercise guidelines.