CEP Calf Sleeves also stabilize the musculature surrounding the venous system in the lower leg, which helps prevent varicose veins and other venous issues. Your veins consist of one-way valves that allow your blood to flow in one direction – upwards towards the heart. If the walls of the veins are loose, these valves do not close properly and can allow blood to backflow into a lower compartment. CEP Calf Sleeves apply 20-30mmHg of pressure to the walls of the veins, which keeps the one-way valves nice and tight and keeps your blood moving in the right direction.