Wearing compression socks during long flights will help your legs with proper blood circulation. While movement is constrained during long flights, your compression socks will work for you. Less movement during travel can lead to heavy legs, swollen feet/ankles and other leg pains. Sitting for a long time is not only uncomfortable; it can also affect your circulatory system. Immobility can even contribute to a potentially life-threatening condition known as deep vein thrombosis (DVT), dangerous blood clots in the legs.