Walking and other aerobic physical activity has a direct effect on your blood's good cholesterol level. Regular physical activity, including walking, also "can help lower LDL (bad) cholesterol," according to the U.S. government's National Cholesterol Education Program. Walking reduces bad cholesterol indirectly by helping you reduce your weight and stress, according to "Controlling Cholesterol" and "The 8-Week Cholesterol Cure." Walking helps men's cholesterol levels more than women's.
Your blood cholesterol levels are crucial because they affect your heart-disease risk. "For every 1 percent drop in blood cholesterol, studies show a 2 percent decrease in the likelihood of a heart attack," according to "An Invitation to Health," a textbook for college students. The National Cholesterol Education Program reports that your heart-disease risk is low if your total cholesterol is less than 200 milligrams per deciliter, your bad cholesterol is less than 100 milligrams per deciliter and your good cholesterol is more than 60 milligrams per deciliter.
Walking is a major part of the solution to improving good cholesterol levels, according to Kenneth Cooper, a well-known author of 18 exercise books. In "Controlling Cholesterol," Cooper reports that brisk treadmill walking for 16 weeks at the University of Minnesota's Laboratory of Physiological Hygiene raised young men's good cholesterol by 16 percent and "very moderate exercise" that consisted "mainly of walking" raised middle-aged men's good cholesterol by 10 percent.
Less body fat is "associated with lower levels of the "bad" LDL cholesterol," wrote Cooper. Losing weight by itself reduces total cholesterol and bad cholesterol levels, but the reductions were the "greatest" in a study by the universities of Colorado and Virginia when exercise was combined with weight loss, reported Cooper. The study showed total and bad cholesterol levels fell 13.2 milligrams per deciliter and 10.1 milligrams per deciliter, respectively. The best cholesterol-lowering exercises are walking, cycling, running, swimming and cross-country skiing, wrote Cooper.
Lower bad cholesterol levels after six to 12 months of aerobic exercise, including walking, can "mean as much as a 30 percent reduction in the risk of coronary artery disease," according to "Essentials for Health and Wellness," a college textbook. Walking 30 minutes three times weekly for 11 years reduced heart-disease deaths by 26 percent, and regular walkers weighed 18 fewer pounds, according to the August 2009 issue of Harvard Men's Health Watch.
Cooper has two walking programs for improving cholesterol levels. If you're between 30 to 50 years old, you should walk 2 miles three times weekly during week one of your program and increase your walking until you're walking three miles four times weekly during week 10 and afterward. If you're older than 50, you should walk one mile four times weekly during week one and increase your walking until you're walking three miles four times weekly during week 12 and afterward.
Aerobic exercise, including walking, helps men's good and bad cholesterol levels more than women's, according to "Controlling Cholesterol." In a University of Pennsylvania study, a 16-week program reduced men's bad cholesterol levels 15.8 percent, but women's by 4.7 percent.