Andy Murray is not sure why he experienced cramps during his opening-round match against Robin Haase at the U.S. Open.
The No. 8 seed had taken a two-set lead and began to cramp at the beginning of the third set, describing it as unusual timing.
"Normally it's kind of a gradual thing, but after maybe two-and-a-half, three hours maybe you start to feel like that," said Murray, who won 6-3, 7-6 (6), 1-6, 7-5. "You know, sometimes nerves can bring it on. I certainly wasn't nervous at the beginning of the third set after just winning a tough second set.''
Fitness was unlikely to be the reason, Murray suggested, saying he would talk to a nutritionist about what he had been eating.
"The fact that it was the whole body would suggest that maybe it was something to do with my eating or drinking, because if it's through fatigue in one part of your body, then, yeah, that would probably be down to conditioning," he said. "But cramping in my left forearm—I mean, I didn't use my left forearm a whole lot today compared with other parts of my body, so I would expect it would be something to do with what I have eaten or something or not eaten."
Murray said that he would not know whether it might re-occur until he found himself in match conditions again, but there was little adjustment to make without first identifying the source of the problem.
"This is the shape I'm in for the tournament. I feel or I felt extremely good before the match, and I did train very, very hard to get ready for the tournament," he said.