Author(s): CHEN, H., CHEN, Y., HSU, H., WANG, J., Institution: CHANG GUNG UNIVERSITY, Country: TAIWAN, Abstract-ID: 1008

INTRODUCTION:
While eccentric exercise may cause muscle damage and inflammation, some studies suggest it does not necessarily impair oxidative function. Additionally, non-invasive ventilation (NIV) can enhance muscle oxygenation, prolong exercise duration, and increase oxygen uptake (VO₂). Further research is needed to clarify its direct effects on muscle oxidative function and the potential benefits of NIV in COPD patients.
METHODS:
Patients diagnosed with COPD were recruited from outpatient clinics and randomly assigned to either the control group (CON, n=14) or the experimental group (EXP, n=12). Participants in the EXP group performed eccentric cycle exercise (ECE) with the assistance of non-invasive helmet ventilation. All participants engaged in 40-minute eccentric cycling sessions twice a week for a total of nine weeks, including a one-week familiarization period. The exercise intensity was set based on the peak oxygen uptake (VO₂peak) measured during a graded exercise test (GXT) before training. Measurements were taken during exercise sessions in the 2nd and 9th weeks to assess hemodynamic status and tissue oxygenation. Additionally, the Borg scale was used to record post-exercise leg fatigue and dyspnea levels.
RESULTS:
In the CON group, O₂Hb and tHb in the vastus lateralis increased significantly from the first to the last session (p=0.035). No significant differences in muscle oxygenation were found between EXP and CON. However, in the first session, EXP had a greater increase in cardiac output (p=0.036) and stroke volume (p=0.018). EXP also reported higher dyspnea than CON (p=0.013), but leg fatigue was similar between groups.
CONCLUSION:
After nine weeks, O₂Hb and tHb in the eccentric exercise group increased significantly. Tissue oxygenation remained stable in both groups, unaffected by helmet-assisted ventilation.