Wimbledon: Chocolate is Isner's final treat if he beats Anderson
The 33-year-old American has long been conscious of the importance of nutrition and diet, but he has been allowing himself a regular chocolate treat during his run to the semi-finals.
“After each win throughout these 10 days I’ve had a KitKat. I’m not going to change that now,” Isner said.
It is a routine that has served Isner well, the ninth seed winning the battle of the ace specialists against Milos Raonic in four sets in the quarter-finals.
He will face a familiar figure in the last four in the shape of 6ft 8ins Kevin Anderson, the conqueror of Roger Federer. Isner stands two inches taller than his South African opponent.
Anderson is a man that Isner played several times on the US college circuit and he leads their professional head-to-head 8-3.
Isner added: “There could be a little mental aspect in our match. I say that because our rivalry goes back way before the pro tour.
“We’ve been lined up against each other for about 14 years now because he left Illinois when I left Georgia. We’ve been doing it ever since.
“For me this match-up, and I think for him as well, is especially cool. It’s a very nice spotlight on college tennis that one of us, no matter what, is going to be playing in the Wimbledon final.
“We’re duking it out in the semi-finals. The two of us went to college, did it a different route. It’s pretty cool.”
Djokovic, back from injury, is looking close to his best after victory over Kei Nishikori while Nadal overcame Juan Martin del Potro in five sets.
The pair have played each other an incredible 51 times, with Djokovic leading the head-to-head by just one.
“There is no one other match in the history of tennis that is played more than our match,” said Nadal. “That’s a big thing. We always played in important stages, important places.
“Friday is another important match against an opponent that is one of the most difficult ones that you can face. He’s playing well.”