Jan. 9 (HealthDay News) -- The American Heart Association (AHA) has recruited actress Jane Seymour to help launch "Start!", a campaign designed to encourage Americans to improve their health through walking.

Each year, 1.2 million Americans suffer a heart attack. In fact, cardiovascular disease and stroke claim 870,000 lives each year, making it the No. 1 killer.

Americans today are working longer hours -- 164 more per year -- than 20 years ago. And many people work in sedentary jobs, which leads to physical inactivity and a greater risk for heart disease and stroke, according to the AHA.

To get Americans up and moving, the heart association is launching "Start!" -- a movement that encourages corporations and their workers to promote physical fitness in the workplace.

The "Start!" campaign is being inaugurated by Dr. Raymond Gibbons, AHA president and a professor of medicine at the Mayo Clinic College of Medicine, in Rochester, Minn.

"I'm excited to be part of this groundbreaking new movement," Seymour said in a prepared statement. "I want to do my part to help get Americans in shape and eating better. 'Start!' is a great way for busy Americans to find the time to make a real change for the better in their lives."

The campaign focuses on walking, because it's a physical activity that is accessible, free and has the lowest dropout rate of any type of exercise. And adults gain two hours of life expectancy for each hour of regular exercise, according to the AHA.

"Regular walking has many proven benefits for an individual's overall health. Brisk walking for 30 minutes a day can lower both bad cholesterol (LDL) levels and high blood pressure. It can help individuals who are overweight achieve and maintain weight loss, and reduce their risk of stroke," Gibbons said in a prepared statement.

The "Start!" campaign is built around four key elements:

• MyStart Online, an online fitness and nutrition calculator.
• The "Start!" Fit-Friendly Companies Recognition Program, which cites employers that champion the health of their employees.
• The "Start!" Walking Program, which encourages walking at work.
• The "Start!" Heart Walk, a fundraiser that combines walking with raising money to fight heart disease and stroke.

From Monday through Feb. 5, people can sign up to receive phone calls from celebrities encouraging them to adopt healthy habits. You can sign up online at the American Heart Association, or by calling the association at 1-800-AHA-USA1.