Elastic-Band Resistance and Breathing Training for Older Adults With Pulmonary Function Impairment

FEV1 z-score was calculated using reference equations to standardize pulmonary function according to age, sex, height, and ethnicity. The change from baseline to Week 12 was used to evaluate standardized improvement in pulmonary function. Higher z-scores indicate better lung function.

FVC z-score was calculated using reference equations to standardize pulmonary function according to age, sex, height, and ethnicity. The change from baseline to Week 12 was used to evaluate standardized improvement in pulmonary function. Higher z-scores indicate better lung function.

FEV1/FVC z-score was calculated using reference equations to standardize the ratio according to age, sex, height, and ethnicity. The change from baseline to Week 12 was used to evaluate standardized change in airflow limitation. Higher z-scores indicate better pulmonary function.

Dominant-side quadriceps strength was measured using a standardized muscle strength testing device. The change from baseline to Week 12 was used to evaluate lower-limb muscle strength. Higher values indicate greater muscle strength.

Forced vital capacity (FVC) was measured using standardized spirometry. The change from baseline to Week 12 was used to evaluate improvement in pulmonary function. Higher values indicate better lung function.

Forced expiratory volume in 1 second (FEV1) was measured using standardized spirometry. The change from baseline to Week 12 was used to evaluate improvement in pulmonary function. Higher values indicate better lung function.

The FEV1/FVC ratio was calculated from standardized spirometry results. The change from baseline to Week 12 was used to evaluate airflow limitation. Higher values generally indicate better pulmonary function.

Non-dominant-side quadriceps strength was measured using a standardized muscle strength testing device. The change from baseline to Week 12 was used to evaluate lower-limb muscle strength. Higher values indicate greater muscle strength.

Dominant-side triceps surae strength was measured using a standardized muscle strength testing device. The change from baseline to Week 12 was used to evaluate lower-limb muscle strength. Higher values indicate greater muscle strength.

Non-dominant-side triceps surae strength was measured using a standardized muscle strength testing device. The change from baseline to Week 12 was used to evaluate lower-limb muscle strength. Higher values indicate greater muscle strength.

The Timed Up and Go test was used to assess functional mobility. Participants stood up from a chair, walked a fixed distance, turned around, returned to the chair, and sat down. Shorter completion time indicates better functional mobility.

The 2-minute step test was used to assess short-duration exercise tolerance. Participants stepped in place for 2 minutes, and the number of valid steps reaching the required knee height was recorded. Higher values indicate better exercise tolerance.

Baseline, Week 6, and Week 12

The 30-second chair stand test was used to assess repeated sit-to-stand ability. Participants were asked to complete as many full sit-to-stand repetitions as possible within 30 seconds. Higher values indicate better lower-limb functional performance.

Respiratory-related health status was assessed using the St. George's Respiratory Questionnaire total score. The change from baseline to Week 12 was used to evaluate respiratory symptoms and health-related quality of life. Lower scores indicate better respiratory-related health status.

Sleep quality was assessed using the Pittsburgh Sleep Quality Index total score. The change from baseline to Week 12 was used to evaluate changes in subjective sleep quality. Lower scores indicate better sleep quality.

Dominant-side handgrip strength was measured using a standardized handgrip dynamometer. The change from baseline to Week 12 was used to evaluate upper-limb and overall muscle strength. Higher values indicate greater muscle strength.

Non-dominant-side handgrip strength was measured using a standardized handgrip dynamometer. The change from baseline to Week 12 was used to evaluate upper-limb and overall muscle strength. Higher values indicate greater muscle strength.

Percentage of prescribed training sessions completed during the 12-week intervention, calculated as the number of completed sessions divided by the number of prescribed sessions × 100. Higher values indicate greater adherence.

Cumulative duration of completed supervised and home-based training sessions during the 12-week intervention, calculated from attendance records and training logs.

Percentage of randomized participants who completed the Week 12 follow-up assessment, calculated as the number completing the assessment divided by the number randomized to each group × 100.