Underwood has stated that she has a great interest in sports. She has participated in the annual City of Hope Celebrity Softball tournament for charity for many years. The event takes place in Nashville, Tennessee, and benefits research for life-threatening diseases. In 2005, she performed the "Star-Spangled Banner" at Game 4 of the NBA Finals between the San Antonio Spurs and Detroit Pistons, and in 2006 at the NBA All-Star Game. She performed at halftime of the 2006 Thanksgiving Day football game at Texas Stadium in Irving, Texas, and was friends with Dallas Cowboys quarterback Tony Romo. She also performed the "Star-Spangled Banner" at the between the Seattle Seahawks and Carolina Panthers in 2006, as well as at the 2006 edition of NASCAR's Coca-Cola 600, the MLB All Star Game in Pittsburgh, and at Game 3 of the 2007 World Series between the Boston Red Sox and Colorado Rockies. On February 7, 2010, Underwood performed the National Anthem for Super Bowl XLIV.