Most Americans know that physical activity is good for them, yet the majority of them are still not active enough to get the health benefits of exercise. This is especially true for women, whose activity levels decline drastically during adolescence and stay much lower than men's for the rest of their lives.

Yet regular exercise can help prevent and relieve some of the major health problems facing females, including heart disease, stroke, osteoporosis and depression. Heart disease is the number one cause of death for women and stroke is number three, according to the American Heart Association, which notes that, since 1984, more women than men have died of heart disease and stroke. One in two women will eventually die of heart disease or stroke, says the AHA, compared with one in 27 who will eventually die of breast cancer.

To help women become active, the AHA worked with experts at the Cooper Institute for Aerobics Research in Dallas to create a 12-week program called "Choose to Move." Designed for busy women who don't have a lot of time or athletic skills, the program features gradual, systematic behavior changes to help increase physical activity levels and lower cholesterol. Over the course of three months, women learn how to:

* Set goals and monitor progress

* Build physical activity into daily life

* Eliminate barriers to healthy living

* Create a support system

* Reduce dietary fat

* Prevent relapse.

The free program includes a handbook, resource list, weekly score sheets and reply cards so women can report their progress to the heart association. As an extra motivator, women who complete the program by Nov. 14 will receive a free Choose to Move T-shirt. To receive the Choose to Move handbook, call 1-888-694-3278 (1-888-MYHEART) or visit the Web site www.women.americanheart.org.

To be eligible for the T-shirt, women must register by Friday, July 30.