This study, titled "Effect of Compound Ejiao Jiang on Exercise Tolerance and Quality of Life of Critically Ill Patients after Discharge from ICU: A Double-Blind, Multicenter, Randomized Controlled Clinical Study (LIFT Study)," intends to enroll 156 patients (78 in the experimental group and 78 in the control group). A double-blind design will be adopted, with patients receiving Compound Ejiao Jiang (20 ml each time, three times a day for 90 consecutive days) or a placebo for intervention. The primary outcome measure is the 6-minute walking distance on the 90th day after randomization. Meanwhile, secondary endpoints such as physical function, quality of life, and nutritional and inflammatory indicators will also be monitored. The aim of this study is to explore the rehabilitation value of Compound Ejiao Jiang for patients with post-intensive care syndrome (PICS) through high-level evidence-based medicine methods and to provide scientific evidence for the integrated traditional Chinese and Western medicine approach to improving the long-term prognosis of critically ill patients