In order to move around the court swiftly, Williams has to be both agile and fast. Her coach Patrick Mouratoglou recently told Shape Magazine that you can't train for that just by sprinting, because that form of cardio only has you running in a straight line. This sport is all about speed and changing direction because you have to do both all the time,” he said. "I'll have her do technical runs side to side, and randomly determine where she's going to run… We can make an exercise where she has to run right, right, left, right, left, left, right, left. Something like that, but she'll go when I signal and they're not in the same time intervals so she doesn't know when it's going to happen."