The study looked at 243 peritoneal dialysis patients to see how their ability to manage fluid overload changes and how it relates to physical activity. The researchers identified three groups of patients according to the trajectory of their behavior changes: a group with a low level of improvement (C1), a group with a moderate level of improvement (C2), and a group with low to moderate fluctuation (C3). Significant differences between groups were found in education level, incidence of diabetic nephropathy, peritonitis during the study, and low blood protein. During the first six months of treatment, the physical activity of all patients increased, with the C2 group showing higher physical activity than the other groups at the start of the study. In the later phases of the study (months 3–6), group C1 achieved higher physical activity than groups C2 and C3. The conclusion of the study states that the patient's education, diabetic nephropathy, incidence of peritonitis and low protein content in the blood affect how patients' ability to manage fluid overload changes. Proper management of fluid overload in the individual phases of treatment has an impact on the physical activity of patients.