First Lady Michelle Obama participates in "Lets Move!" tennis clinic at the U.S. Open in New York

Tennis greats Billie Jean King (L), Katrina Adams, and John McEnroe are introduced during the Let’s Move! tennis clinic held during the U.S. Open at the National Tennis Center on September 9, 2011 in New York City. Obama's " Let’s Move!" initiative aims to stress the importance of physical activity for kids. UPI/Monika Graff