We have become quite used to celebrity question and answer sessions on Twitter and yesterday,star athlete,Serena Williams,on Friday had a "SerenaFriday" question-and-answer session on Twitter, which led to the question about her interest in running the New York City marathon like her fellow tennis star, Caroline Wozniacki. 'My ass is too big';Serena responded.That might have been surprising to many but equally as honest,I must admit. Considering her athletic figure,one would think she would make her a pretty solid distance runner which is likely correct. We get your point,Serena and it is a valid one,too.