Roger Federer's credits his longevity, in part, to a man who never played pro tennis.
Pierre Paganini, who has been working as Federer's fitness trainer for 18 years, is one reason why the reigning Australian Open champion has played some of his most dynamic tennis at the advanced age of 36.
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Their relationship, which features more than fitness work, goes back 20 years.
"I guess I was very lucky, you know, to meet Pierre when I was 14 years old and I joined the National Tennis Center," Federer told the media after his fourth-round win. "He was running the program as a fitness coach. He was also taking care of the tennis coaches and everything. Because he was already very experienced, having had, you know, with the Maleeva sisters, who were very successful; one played for Switzerland and the other for Bulgaria. He also worked with Marc Roset in the past, who was part of the Davis Cup team.
"When I met him, he was already very experienced at the time and knew exactly, coming from decathlon, what to do in terms of fitness in tennis because he's very creative. I worked there with him for a little bit for two years. He was taking more care of the older guys, Severin, my coach, actually. I saw him from time to time but I had a fitness coach who was using the methods that Pierre was telling him to do with us."
The 54-year-old Paganini says the key to training Federer is challenging him.
"For Roger, you have to be good to find exercises that give him trouble," Paganini told The New York Times' Christopher Clarey. "He’s so coordinated. In 2000, when we started working full-time again, I proposed a complex thing and sensed while he was doing it that it was more and more perfect. He then explained at the end why I had asked him to do it. It was fascinating to me. He had understood as an athlete how to do it but also understood why. He had the internal and external aspects covered. He’s not someone who consumes. He’s someone who creates."
Together, Paganini and Federer built the fitness foundation that has helped him win 19 Grand Slam titles.
"I didn't work with him from 16 to 19 and starting in 19, ever since I worked with Pierre again, you can imagine the impact that he's had on my career as a fitness coach but also a little bit as a mentor, to be honest, because we do a lot of talking besides working," Federer said. "You always count an extra 45 minutes where we just talk about everything. I love every session that, you know, we worked together, and without him I don't think I would have been as fit or as fast in my career, so a lot of credit goes to him."