To counter those obstacles, the nonprofit Women's Sports Foundation, founded 30 years ago by Billie Jean King, is trying to get girls ages 8 to 18 exercised about exercise.

The program, called GoGirlGo!, is rooted in government and medical statistics that link inactivity to increasing rates of obesity and other health problems, including breast cancer and osteoporosis, and escalating health costs.

"The inactivity of youngsters has long-term consequences we can't ignore," says Donna Lopiano, foundation executive director.

During the three-year initiative, the foundation hopes to get 1 million girls active and keep another 1 million girls from stopping their physical activity and will track their participation.

The program provides:

• $2.6 million in grants for activity programs that serve economically disadvantaged girls.

• Kits to program participants that include advice from Olympic and other top female athletes about health issues.

• Adults as mentors for girls and high school athletes as peer leaders who promote exercise.

• The Gogirlgo.com Web site that includes tips on taking up any of 100 sports — from the common to the more unusual, such as dog-sledding and parachuting.

• Corporate partnerships to promote the program with apparel, products and sponsorships.

Sports psychologist Doreen Greenberg says girls are especially susceptible to peer pressure, are afraid of being labeled jocks and don't receive as much encouragement from their parents or other adults to participate in sports.

However, foundation officials are not stressing competitive sports. "Being physically active isn't just about throwing a ball or sprinting somewhere," says Dawn Riley, foundation president. "We're trying to make it so that it's easy, it's fun."