Following intense exercise some people with varicose veins may feel their legs more swollen, more tired and painful. In these cases the problem is the varicose veins and not the exercise. An insufficient venous system cannot respond to the increased circulatory demands during exercise. Exercise though does not worsen varicosities, but rather calms them down. Any kind of athletic activity can only improve the leg circulation. Particularly walking or running makes your calf and thigh muscles contract, thus acting like a pump that pushes blood out of the leg. Still, at advanced stages symptoms may worsen with exercise (venous claudication).
Exercise is strongly advised for patients with varicose veins. If exercise worsens the symptoms then either the underlying venous insufficiency has progressed significanltly or the symptoms are of other origin.