Ganjoji Yakushido is a temple in the central Japanese city of Nagoya. This time of the year, some of the best sumo wrestlers are gathering for the Nagoya Grand Sumo Tournament. Here is a rare look at their lives before the contest.. All photos Issei Kato/Reuters

The sound of bodies slapping against each other rocks the stifling sumo stable as 11 gigantic wrestlers in loincloths take turns throwing each other out of a ring of sand.

The tough training and tradition-bound ways have put many locals off the sport, leaving sumo to be dominated by foreign, mainly Mongolian, wrestlers.

After ending their morning practice, the wrestlers mingle with fans, sign autographs and pose for photos before the first of their two daily meals.

Lunch, prepared by the junior wrestlers, is a spread of pig’s feet, grilled and deep-fried sardines, steamed rice and ‘chanko nabe’ – a signature hotpot dish associated with sumo wrestlers, who are said to consume 8,000 calories a day.

To maintain their heft, the wrestlers nap for several hours immediately after eating, wearing masks to aid breathing.

Life as a wrestler is highly regimented. On entering sumo, they are expected to grow their hair long to form a topknot similar to the samurai hairstyles of the Edo period.

The sumo lifestyle can have negative health effects with diet and the sport taking a toll on the wrestler’s body. Recently, the standards of weight gain have become less strict, in an effort to improve the overall health of the wrestlers.

The wrestlers, or rikishi, taking time out from training. They spend more than three hours each morning practising holds.