London — Michelle Obama formally opened her stint as leader of the US Olympics delegation on Friday, attending a breakfast with Olympians and saying she was "just in awe" of their company.The US first lady mingled with the US athletes afterward, posing for photos, shaking hands and sharing hugs with dozens who had signed up to attend."Try to have fun. Try to breathe a little bit," Mrs Obama said. "But also win, right?"The first lady had a busy itinerary on Friday, including promoting healthy living with more than 1 000 children, a reception hosted by Queen Elizabeth II at Buckingham Palace and then the opening ceremony at Olympic Stadium.She told the US athletes that some of her fondest memories in sports stemmed from watching the Olympics on television. She also shared the story of her father, who was athletic but contracted multiple sclerosis "in the prime of his life"."He retained his love of sports, truly," Mrs Obama told the athletes. "And the Olympics was a special time for him to watch amazing athletes of all abilities compete on the world stage."Mingling"Every few years, these games bring pride, excitement and wonder to millions of people around the world. And that must mean so much to all of you," she added.Later, the first lady met with hundreds of children on the lavish grounds of Winfield House, the official residence of the US ambassador in London.As the University of Florida Gator marching band paraded and twirled batons, children hurried between sports areas and mingled with athletes.Soccer hero David Beckham appeared alongside the first lady, Olympic gold-medal sprinter Carl Lewis signed autographs, and ex-NBA star Dikembe Mutombo offered the kids — most of them from US military families — tips on basketball.A former Manchester United goalkeeper and members of the US field hockey and tennis squads also ran training sessions for the children, aged nine to 14 years old.The event was part of the first lady's "Let's Move!" campaign, aimed at tackling childhood obesity and promoting sports.Excitement"I think this is amazing and what the first lady has done to get kids to move is truly wonderful," said Lewis. "Both she and the president love the Olympics and the Olympic movement."Student Ethen Duval, originally from Oklahoma, sharpened his skills at the soccer camp."I'm looking forward to watching the Olympic soccer," said the 10-year-old, who lives at Lakenheath US Air Force Base in Britain. "I can't wait to watch things with my Dad and see the look on his face when something exciting happens and he says 'Wow!'"The 46-year-old Mutombo towered above his young pupils, who were eager for the Olympics to begin."They are mostly excited about the basketball," he joked.The breakfast took place at the University of East London, where the US Olympic Committee has established a full training facility that will host hundreds of athletes during the games.'Otherworldly'Among the Olympians attending were two-time fencing gold medallist Mariel Zagunis, chosen by US athletes to carry the nation's flag into the opening ceremony, along with the US women's basketball team and members of the track and field squad.Mrs Obama appeared with several past US Olympic and Paralympic standouts, including Brandi Chastain, Gabriel Diaz de Leon, Grant Hill, Summer Sanders and Dominique Dawes."Being here is otherworldly for me," the first lady said. "I am still so inspired."On Saturday, Mrs Obama will meet with Samantha Cameron, the wife of British Prime Minister David Cameron, before watching US athletes on the first full day of Olympic competition. She will see more events on Sunday before departing.Other first ladies who have led recent US Olympic delegations include Hillary Clinton at Lillehammer in 1994 and Laura Bush at Turin in 2006.