The benefits of exercise are widely known, "yet few of us look upon physical inactivity as a clear risk factor for heart disease," says Dr. David D. Cosca, assistant clinical professor of family practice at the UC Davis School of Medicine and one of six lecturers in the 1992 UC Health Net Wellness Lecture Series. Studies show that 80 percent of Americans are less physically active than necessary for cardiovascular benefit, a figure prompting the Centers for Disease Control and the U.S. Preventive Services Task Force to conclude that "physical inactivity is the CHD (coronary heart disease) risk factor of potentially greatest public health impact." Cosca will speak on "Physical Inactivity: The Neglected Coronary Artery Disease Risk Factor" at 5 p.m. Tuesday, Oct. 13, in Lecture Hall 180, Medical Sciences Building 1C, on the Davis campus.