Exercise therapy (ET) is crucial for preventing and managing Post-Intensive Care Syndrome (PICS), a complex condition affecting physical, cognitive, and mental functions after ICU discharge. This review summarizes current evidence on ET's role in ICU and post-discharge settings, highlighting its benefits in improving physical, cognitive, and mental functions. ET is defined as any physical activity that helps maintain or improve muscle strength and function. It includes passive, assisted, and active interventions. ET has been shown to be safe and effective during and after ICU admission, with recent research focusing on optimal dosing, timing, and adjunctive interventions. Emerging technologies like virtual reality and robotics are being explored to enhance ET delivery. Challenges include ensuring consistent ET delivery, addressing individual patient needs, and improving post-ICU rehabilitation. ET is associated with reduced muscle atrophy, shorter ICU stays, and improved functional capacity. It also has positive effects on cognitive and mental health, reducing delirium and improving quality of life. ET is recommended as a key component of ICU rehabilitation, with early initiation and continued use post-discharge. Future research should focus on personalized ET approaches, prediction models for PICS risk, and multidimensional interventions combining ET with nutrition, sleep, and environmental factors. The review emphasizes the need for further research to optimize ET and improve outcomes for ICU survivors.Exercise therapy (ET) is crucial for preventing and managing Post-Intensive Care Syndrome (PICS), a complex condition affecting physical, cognitive, and mental functions after ICU discharge. This review summarizes current evidence on ET's role in ICU and post-discharge settings, highlighting its benefits in improving physical, cognitive, and mental functions. ET is defined as any physical activity that helps maintain or improve muscle strength and function. It includes passive, assisted, and active interventions. ET has been shown to be safe and effective during and after ICU admission, with recent research focusing on optimal dosing, timing, and adjunctive interventions. Emerging technologies like virtual reality and robotics are being explored to enhance ET delivery. Challenges include ensuring consistent ET delivery, addressing individual patient needs, and improving post-ICU rehabilitation. ET is associated with reduced muscle atrophy, shorter ICU stays, and improved functional capacity. It also has positive effects on cognitive and mental health, reducing delirium and improving quality of life. ET is recommended as a key component of ICU rehabilitation, with early initiation and continued use post-discharge. Future research should focus on personalized ET approaches, prediction models for PICS risk, and multidimensional interventions combining ET with nutrition, sleep, and environmental factors. The review emphasizes the need for further research to optimize ET and improve outcomes for ICU survivors.