(Credit: John Angelillo/UPI/Newscom)

Michelle Obama helped kick off the 2013 U.S. Open today, telling an audience of kids that she grew up in a Chicago community without tennis but eventually forced her children to play it because it's "a lifelong sport."

The first lady, who was introduced by Serena Williams, used the opportunity of Arthur Ashe Kids Day, which launches the U.S. Open at the USTA Billie Jean King National Tennis Center in Queens, N.Y., to promote her "Let's Move" campaign.

King herself was in attendance, receiving praise from the first lady as "a living legend who has meant so much to me, so much to women, so much to young people and young athletes all over this country."

In the course of promoting tennis as a lifelong sport that can teach children the value of hard work and keep adults exercising into old age, Obama revealed that she forced her two daughters, Sasha and Malia, to play tennis because of its virtues.

"It's a great way to stay healthy, to stay fit, it's a lifelong sport, it's something I've tried to tell my kids - I forced them into playing tennis, because I didn't want them to be like me, but it's a great way to stay active," the first lady said. "And today I don't worry about how good I am, because I'm not very good, so it's easy."

Obama said she grew up in a community where tennis wasn't played, on Chicago's South Side.

"When I was your age, I didn't have tennis role models, I didn't live in a community where there were any tennis courts, and quite frankly I don't think I knew a single person when I was young who even knew how to play tennis," she said.

Obama praised the United States Tennis Association (USTA) for partnering with her "Let's Move" children's health campaign and pledging to donate hundreds of thousands of dollars, build thousands of courts, train thousands of tennis instructors, and teach the game to hundreds of thousands more kids through summer and after-school programs.

Joined by athletes onstage, Obama urged children to play tennis as a lifelong sport that will help them learn the value of hard work and practice.

"You're going to learn things like hard work, teamwork, discipline. That's why playing sports is so important, and that's what sports teaches you. It teaches you that if you keep on practicing, and giving 100 percent to anything you do, you will get better at it, and that's not just true on the tennis court, but that's also true in the classroom as well," the first lady said.

"If you want to be good at anything, you have to work at it," she said. "I know your parents tell you that all the time, but I want to emphasize it, if you want to be good at anything, you have to put the work in," she said.