On Tuesday, Olympic swimming legend Michael Phelps responded to criticism over his 'Phelps vs. Shark' event during Discovery Channel's 'Shark Week'. On Sunday, Discovery aired a special where Phelps tried to beat the speed of a great white in a 100-meter race. However, many viewers were left disappointed when it was revealed that he raced a digitally added CGI shark due to safety concerns. In a post to his Facebook page, Phelps said, "For those of you who are disappointed, I'm sorry for that. But I absolutely had one of the most exciting two weeks of my life being able to dive with these animals, and see these animals up-close and personal, and really, just honestly learning more about them."