Abstract: bjective  To explore the effects of enhanced external counterpulsation (EECP) combined with aerobic and resistance exercise on cardiopulmonary reserve capacity and exercise endurance in MHD patients with frailty.  Methods  Elderly MHD patients with frailty admitted to Nanjing Medical University Affiliated BenQ Hospital from January to December 2023 were prospectively selected as the research subjects. They were randomly divided into the exercise group, EECP group, and combined group using the digital randomization method. All three groups were observed for 3 months, with primary assessment indicators including cardiopulmonary reserve capacity, exercise tolerance, and quality of life.  Result  A total of 129 patients were included, with 43 in each of the exercise, EECP, and combined groups. After treatment, significant differences were observed among the three groups in stroke volume (SV) (F=8.015, P=0.001), left ventricular end-systolic volume (LVESV) (F=7.832, P=0.001), and left ventricular ejection fraction (LVEF) (F=3.992, P=0.021). After treatment, significant differences were found among the three groups in peak expiratory flow (PEF) (F=28.923, P<0.001), forced vital capacity (FVC) (F=56.482, P<0.001), forced expiratory volume in the first second (FEV1) (F=40.780, P<0.001), and tidal volume (VT) (F=71.835, P<0.001). Post-treatment comparisons among the three groups revealed significant differences in peak load power (WR) (F=66.005, P<0.001), peak oxygen pulse (peak VO2/HR) (F=228.830, P<0.001), peak metabolic equivalent of task (METs) (F=88.218, P<0.001), anaerobic threshold (AT) (F=28.485, P<0.001), peak oxygen uptake (peakVO2) (F=20.617, P<0.001), 6-minute walk distance (6MWT) (F=37.617, P<0.001), and 30-second sit-to-stand test (30s-STS) (F=43.287, P<0.001).  After treatment, significant differences were observed among the three groups in the Spitzer Quality of Life Index (SQLI) and Frailty Phenotype (FP) scores (F=44.025, 64.500; both P<0.001).Conclusion  Both EECP and aerobic and resistance exercises have positive effects on improving cardiopulmonary function and exercise endurance in elderly MHD patientswith frailty, with combined intervention yielding better outcomes.

Key words: Maintenance hemodialysis, Frailty, Enhanced external counterpulsation, Exercise endurance, Cardiopulmonary reserve capacity