WATCH: Novak Djokovic tries sumo wrestling, feels ‘out of shape to compete’

Novak Djokovic during the sumo wrestling session. (Source: Twitter/@ATP_Tour)

Novak Djokovic was given a reality check about being one of the fittest athletes in the world, when he tried wrestling with retired sumo professionals in Tokyo on Monday, as he felt that he was "out of shape".

The 32-year-old Serb, who is in Tokyo to play in the Japan Open Tennis Championships, visited a traditional dohyo to watch the sumo wrestlers during their morning practice.

"I felt I’m out of shape a little bit… with a few more kilos, I’ll be ready to compete. Probably three times as much as I have right now would be the right measurement for me to compete," Djokovic told the ATP website, after unsuccessfully attempting to make one of the wrestlers budge.

"It’s quite impressive to see also how flexible they are. I didn’t think that they were that flexible considering it’s a heavyweight sport."

"But I see that they are paying a lot of attention to the mobility of their joints, which is of course what allows them to move around as agile as possible at their weight."

"It’s a great experience, one of the most popular sports in Japan. Speaking with my father yesterday on the phone, I was telling him that I’m going to have an opportunity to meet sumo wrestlers," the 16-times Grand Slam singles champion added.

Djokovic, who plays 20-year-old Australian Alexei Popyrin in the first round on Tuesday at the Ariake Coliseum, recalled watching Yokozuna Akebono who became sumo’s first foreign-born grand champion in 1993.

"He and I were remembering many years ago when we used to watch Akebono… someone we supported a lot."

Earlier on Monday, Bruno Soares of Brazil and Mate Pavic of Croatia beat the World #1 and fellow Serbian Filip Krajinovic 6-2, 4-6, 6-4 to progress to the men’s doubles quarter-finals of Japan Open.