Last weekend, women made sports news -- and sports history -- all over the planet. Danica Patrick became the first female winner on the IndyCar circuit when she drove under the checkered flag in Japan. The supremely talented Lorena Ochoa won her fourth consecutive LPGA tournament.

During the same time frame, millions of girls sat indoors on a sparkling spring weekend and did ... nothing. No walking, no biking, no playing catch, no skipping rope. That dichotomy is highlighted in a new report by the University of Minnesota's Tucker Center, which found that physical activity among American girls is declining even as more of them participate in organized sports.

The report updates the Tucker Center's landmark 1997 study on the role of sports and physical activity in girls' lives. It's a good-news, bad-news document that ought to serve as a call to action. Research consistently shows that sports and exercise enhance girls' health, self-esteem and social development, just as they do for boys. But the Tucker Center report shows that barriers to participation still exist, and it's time to get serious about knocking them down.

"We need to look at physical activity as a core value, not as an add-on," said Nicole LaVoi, associate director of the Tucker Center who will join other authors of the report for a lecture at 7 p.m. tonight at the Cowles Auditorium. "We are placing a national asset at risk.

"Girls are half the population. They are an increasing majority on college campuses and are positioned to be a major force across the board. But they are at risk for being unhealthy and unhappy. There is a lot of work to be done."

The Tucker Center, a research institute at the U that studies girls and women in sport, commissioned the update of its 1997 study produced in concert with the President's Council on Physical Fitness and Sports. The original report helped change attitudes about women's sports participation by describing how physical activity enriches bodies and minds.

For the update, the authors reviewed research conducted since that time. Recent studies continue to prove the benefits of sports. They include a reduced risk of obesity and such illnesses as Type II diabetes and cardiovascular disease; higher grades and lower dropout rates, and development of social skills. Girls are participating in organized sports in record numbers, from youth leagues to elite professionals.

But research also shows that girls still face significant obstacles to participation, which do not seem to have abated in the past 10 years. They might live in poverty or in an ethnic community that doesn't see value in sports for girls. They might be expected to stay at home and engage in more traditional gender roles. They face stereotypes of athletics as "unfeminine," and they might not have access to activities they enjoy, particularly if they are not interested in serious competitive sport.

The legacy of Title IX is apparent in the great leap forward in sports participation. One in three girls now is active in sports, compared to one in 27 in 1972. On the flip side, one-third of all American girls are completely sedentary, and the other third meet only minimal standards of physical activity. Outside of organized sports, girls' participation in physical activities is waning.

"There's a misconception that girls aren't as interested in sports," said Diane Wiese-Bjornstal, an associate professor at the U and one of the report's authors. "Girls like sports. They do want them, although they might want different types of opportunities. We need to get out of the way and stop putting up barriers to stifle their natural enthusiasm."

So how do we do that? Perhaps the greatest value in the Tucker Center report comes in its final chapter, which lists ways to put the research into practice.

The authors say change can come through support from parents and mentors, emphasis on positive role models and activities that provide a comfortable, pressure-free environment. But it won't happen if we don't take action. Here's a suggestion: Take a girl for a walk, or play a game of horse, or teach her how to do a cartwheel. Once she gets moving, all of us will benefit from her forward progress.

Rachel Blount • rblount@startribune.com